Tuflow - User contributions [en]

Flood Modeller Tutorial Module01

2026-03-30T13:34:11Z

RussellGardner: /* Troubleshooting for HPC Simulation */

=Introduction=
In this module, an existing 2D TUFLOW domain is linked to a Flood Modeller 1D model.

The 2D domain represents the floodplain, while the 1D model represents the watercourse and in-channel structures. Linked 1D–2D models combine the strengths of both approaches. Here, the 1D scheme represents the largely unidirectional flow of the watercourse, while the 2D scheme captures the more complex floodplain hydraulics.

In the below 2D model example, the main channel is only 5-10 m wide, making the 5 m grid resolution too coarse to represent it accurately. This reduces the accuracy of conveyance within the channel. 
[[file:Poor_2d_rep.png|400px]] There are several options for improving the representation of this creek channel:
* Decrease the width of the 2D cells, either globally or by using Quadtree, and/or apply sub-grid sampling.
* Model the channel as a 1D network dynamically linked to the 2D domain (the floodplain).
For this module, the second option will be demonstrated.

TUFLOW can also link with other 1D solvers, including ESTRY (TUFLOW 1D), XP-SWMM and 12D Solutions’ Dynamic Drainage. Setting up a channel that cuts through a 2D domain is typically one of the more time-consuming modelling tasks.

For this module, the complete Flood Modeller 1D model network has been provided, to allow for progressing through the module in a relatively short period of time.

===Linking Flood Modeller to TUFLOW===

It is assumed from the outset of this module that Flood Modeller has already been linked to the desired version of TUFLOW. There are four methods by which Flood Modeller and TUFLOW can be linked, all of which are described on this [[Running_linked_Flood_Modeller_-_TUFLOW_Models | page]].

Using the Flood Modeller interface to set the location of the TUFLOW engine files for the TUFLOW build you want to use, is the simplest approach to linking Flood Modeller and TUFLOW and does not duplicate files. This method is recommended if it is expected that the same versions of Flood Modeller and TUFLOW will be used consistently when running linked models.

1) Open the Flood Modeller software and in the 'Home' tab select the 'General' option. 
[[file:FM Home Tab.png|500px]] 

2) Select the 'Project Settings' sub-menu and within the TUFLOW Engine File Location choose to browse to the version of TUFLOW that you would like to link Flood Modeller to. Choose 'Open' and then 'OK'. It is recommended that the option 'Show Solver Window when Running Simulations' be switched on as well. 

[[file:FM TUFLOW Linking 26092025.png|500px]] 

3) Save the changes that you have made to the setup. This will update the settings file (formed.ini).

4) Restart Flood Modeller to effect the revised setting.

4) The linked model can then be run by opening the .ief file within the Flood Modeller Interface and clicking Run. 

=Existing Model Data=
This tutorial builds upon the 2D TUFLOW domain that was constructed as part of [[Tutorial_M01 |Module 1]] and [[Tutorial_M02 |Module 2]] of the TUFLOW Tutorial Model.

The model developed in these tutorial modules already contains some culverts modelled as 1D elements. The culverts are modelled in ESTRY, TUFLOW's internal 1D engine. One of these culverts will be kept in ESTRY and the other will be added to the Flood Modeller model. The 2D boundary conditions (upstream inflows and downstream stage-discharge boundary) will be removed from the model. These will instead be represented in Flood Modeller as it is a more typical schematisation for a 1D/2D linked model.

The existing TUFLOW model consists of:
*Definition of Active/Inactive Areas
*Definition of Land Use areas for the spatial distribution of roughness values
*1D ESTRY culverts
*1D/2D boundary links to connect the 1D ESTRY culverts to the 2D TUFLOW domain.

= Project Initialisation =
TUFLOW models are separated into a series of folders which contain the input and output files. The recommended set up for the model directory and sub-folders is shown below. For a more detailed description, refer to the [https://docs.tuflow.com/classic-hpc/manual/2025.2/FoldersFileTypesandFileNaming-2.html#FoldersFileTypesandFileNaming-2]. 
<ol>
[[File:Tute M01 Directory Structure v3.png|left]]
{| class="wikitable"

! style="background-color:#005581; font-weight:bold; color:white;"| Sub-Folder
! style="background-color:#005581; font-weight:bold; color:white;" width=10%| Input / Output
! style="background-color:#005581; font-weight:bold; color:white;" width=75%| Description
|-
| bc_dbase|| Input || Boundary condition database(s) and input time-series data.
|-
| check|| Output || GIS and other check files to carry out quality control checks (use Write Check Files).
|-
| model|| Input ||Geometry (TGC), Boundary (TBC) and other model control text files (i.e. no GIS files).
|-
| model\gis|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\gis is typically used for all QGIS and ArcGIS files.
|-
| model\mi|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\mi is typically used for MapInfo formatted GIS files.
|-
| results|| Output|| TUFLOW outputs the results to this folder in specified formats.
|-
| runs|| Input|| TUFLOW Control Files (TCF).
|-
| runs\log|| Output || TUFLOW log files (TLF) and messages layers.
|}
</ol>
The TUFLOW folders can be set up manually, automatically running TUFLOW model with <tt> Write Empty GIS Files </tt> command or automatically through GIS programs:
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS | QGIS - SHP]]
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS_GPKG | QGIS - GPKG]]
:*SMS - the folder structure listed above is automatically created before running the model using the 'Export TUFLOW files' command (see [[Run TUFLOW from within SMS | Run TUFLOW from within SMS]]).
:*ArcMap (10.1 and newer) - the ArcTUFLOW Toolbox can be used to automatically create the model folders, model projection, TUFLOW control files and run TUFLOW to create the template files.

The following points on TUFLOW folders and filenames are worth noting:
:*TUFLOW accepts any folder structure, though the above listed format is most commonly used and is recommended. 
:*TUFLOW accepts spaces and special characters (such as ! or #) in filenames and paths, but other software may not. It is recommended that spaces and other special characters are not used in the simulation path and filenames. 
:*Folder paths, filenames, file extensions and TUFLOW commands are not case sensitive in any TUFLOW control files. 
:*Any directories that don't apply can be omitted, for example, if using QGIS or ArcMap the model\mi directory is not required. 
 

= Model Familiarisation=
Become familiar with the model location, using an aerial image and DEM: 
:*[[Model_Familiarisation_QGIS | QGIS]]
 

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module01_Archive |Tutorial Module 01]].

===Define the External 1D Networks===
This part of the module creates the GIS layers that specify the location of the Flood Modeller nodes that are to be connected to the 2D domain.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_x1D_Nodes | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_x1D_Nodes | QGIS - GPKG]]

===Define the Water Level Lines===
This part of the module creates the Water Level Lines that will be used to visualise 1D results in 2D map outputs.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_WLL_Lines | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_WLL_Lines | QGIS - GPKG]]

===Define the 1D/2D Boundary Links===
This part of the module creates the 1D/2D boundaries to link the Flood Modeller 1D component to the TUFLOW 2D domain.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Links | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Links | QGIS - GPKG]]

===Define Bank Elevations===
This part of the module defines the bank elevations of the watercourse which are the elevations of the 1D/2D boundary links created in the previous section.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_Banks | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_Banks | QGIS - GPKG]]

===Deactivate 2D cells ===
This part of the module describes the steps to deactivate the 2D cells where the 1D model is replacing the 2D solution.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Code | QGIS – SHP ]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Code | QGIS - GPKG]]

=Modify Simulation Control Files=

With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.

== TUFLOW Geometry Control File (TGC) ==
At this stage, the following changes will be made to the geometry:
* The cells along the watercourse that are represented in the 1D Flood Modeller component of the model are deactivated.
* Bank elevations along the watercourse are enforced.

<ol>
<li> In the '''FMT_Tutorial\FMT_M01\TUFLOW\model''' folder, save a copy of M01_5m_002.tgc as FMT_M01_001.tgc. </li>

<li> Open FMT_M01_001.tgc 
'''QGIS - SHP''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt>..\model\gis\2d_code_FMT_M01_001_R.shp 
<tt>Read GIS Code BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_R.shp <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R.shp''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R.shp''' deactivates selected cells along the watercourse.

 '''QGIS - GPKG''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt> 2d_code_FMT_M01_001_R 
<tt>Read GIS Code BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_R <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R''' deactivates selected cells along the watercourse. </li>

<li> Topography amendments should be added in a new section at the bottom of the TGC. These are: 
'''QGIS - SHP''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> gis\2d_bc_FMT_M01_HX_001_L.shp | gis\2d_bc_FMT_M01_HX_001_P.shp <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P.shp''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L.shp''' layer (defining bank location).

 '''QGIS - GPKG''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> 2d_bc_FMT_M01_HX_001_L | gis\2d_bc_FMT_M01_HX_001_P <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L''' layer (defining bank location). </li>

<li> Save the file. The geometry control file is now ready to be used. </li>
</ol>

==TUFLOW Boundary Control File (TBC)==
Next, update the TBC to reference the model boundary files created in the previous steps, as described below:

*Add the 1D/2D boundaries that link the Flood Modeller open channel to the 2D floodplain.
*Update the 1D/2D boundaries which link the ESTRY culverts to the 2D floodplain, as some of these culverts are now modelled in Flood Modeller.
*Remove the external inflows applied to the TUFLOW model, as these are now applied in Flood Modeller.

<ol>
<li> Open '''M02_5m_001.tbc''' and save a copy as '''FMT_M01_001.tbc'''.
<li> Remove the boundary linking to the TUFLOW inflows by putting an exclamation mark before the line reading: '''QGIS - SHP''' <tt>Read GIS BC</tt> <tt>== </tt> gis\2d_bc_M01_002_L.shp '''QGIS - GPKG''' <tt>Read GIS BC</tt> <tt>== </tt> 2d_bc_M01_002_L

<li> Add reference to the 1D/2D boundary links that connect Flood Modeller to the 2D floodplain:

 '''QGIS - SHP''' <tt>Read GIS BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_P.shp | gis\2d_bc_FMT_M01_HX_001_L.shp <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt> '''QGIS - GPKG''' <tt>Read GIS BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_P | 2d_bc_FMT_M01_HX_001_L <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt><li> Save the file. The boundary control file is now ready to be used.

</ol>

== TUFLOW Control File (TCF) ==
Finally, the TCF is updated as follows:
<ul>
<li>Remove references to model parameters that are read from Flood Modeller.
<li>Read in the GIS layer of the Flood Modeller nodes.
<li>Read in the GIS layers used to create Water Level Lines along the Flood Modeller component of the model (optional).
<li>Add a reference to the ESTRY Control File.
<li>Update references to the TBC and TGC.
</ul>The following steps outline how to apply these updates:

# In the \FMT_Tutorial\FMT_M01\TUFLOW\runs folder, save a copy of the TUFLOW file created as a part of [[Tutorial_M02 |Module 2]] ('''M02_5m_001.tcf''') as '''FMT_M01_001.tcf.'''
# Remove the Start Time, End Time, and 2D Timestep parameters from the TCF, as these are read from the Flood Modeller .ief file in a linked Flood Modeller-TUFLOW model. If they are left in place the Flood Modeller settings will override the TUFLOW settings. This is done by adding an exclamation mark in front of each of the following commands. <tt>! SIMULATION TIME CONTROL COMMANDS</tt> <tt>Timestep </tt> <tt>== </tt> 1.5 <tt>! Specifies a 2D computational timestep of 1.5 seconds </tt> <tt>Start time </tt> <tt>== </tt> 0 <tt>! Specifies a simulation start time of 0 hours</tt> <tt>End Time </tt> <tt>== </tt>3 <tt>! Specifies a simulation end time of 3 hours</tt>
#Read in the GIS layers of the Flood Modeller Nodes. Place the below command line anywhere in the .tcf. It is good practice to create a section within the .tcf to reference all 1D commands: '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
#Add commands to read in the GIS layers referencing Water Level Lines drawn along the Flood Modeller component of the model: '''QGIS - SHP''' <tt>Read GIS X1D Network</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nwk_001_L.shp <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> ..\model\gis\1d_x1d_WLL_FMT_M01_001_L.shp <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> '''QGIS - GPKG''' <tt>Read GIS X1D Network</tt> <tt>== </tt> 1d_x1d_FMT_M01_nwk_001_L <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> 1d_x1d_WLL_FMT_M01_001_L <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> The addition of TUFLOW Water Level Lines (WLL) allows the Flood Modeller 1D results to be visualised within the TUFLOW 2D map outputs. They provide a means by which to remove the gaps in the map outputs where the 1D Flood Modeller domains are located and the 2D cells are deactivated. To do this, TUFLOW requires a 1D_WLL layer to define the cross sections locations, and a 1d_nwk layer that defines the river centre line. The layers are not used in the hydraulic calculations and their inclusion is not always required. The Dist_for_Add_Points determines the intervals in metres at which interpolation points are inserted along each WLL.
#Add commands to read in an ESTRY Control File which contains references to some of the culverts present on the floodplain: <tt>ESTRY Control File</tt> <tt>== </tt>..\model\FMT_M01_001.ecf <tt>!Reference the ESTRY Control File </tt>
#Update the links to the Geometry control file, the Boundary Condition control file and the bc_dbase file: <tt>Geometry Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tgc <tt>BC Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tbc <tt>BC Database</tt> <tt>== </tt>..\bc_dbase\bc_dbase_FMT_M01.csv
</ol>
This concludes the changes needed to be made to the TCF.

=Flood Modeller Simulation Files=
A complete Flood Modeller model is provided in the '''FMT_M01\Flood_Modeller''' folder. The model files are located in the DAT, IED and IEF folders.

The DAT and IED files are complete and do not require modification to link with TUFLOW. The IEF file must be altered to create the link. These alterations can be made in a text editor or in the Flood Modeller interface.

The instructions below are written for Flood Modeller interface version 7.2.

===IEF File===
<ul>
<li> Open Flood Modeller. Select 'Load 1D Network'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\DAT''' and load the '''FMT_M01_001.dat'''.</li>
<li> Right click 'Event Data' and select 'Add Item'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' and load the '''FMT_Inflows.IED'''.</li>

<li> On the 'Simulation' tab, click New 1D Simulation. Save the file when prompted in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IEF''' folder as '''FMT_M01_001.ief'''</li>
<li> On the 'Files' Tab of the simulation window, set the following parameters:</li>
*Event Title: FMT_M01_001
*1D Data File: The full path to the \FMT_Tutorial\FMT_M01\Flood_Modeller\DAT\FMT_M01_001.dat
*Use Initial Conditions from: Network File (.dat)
*Results File: set the full path to \FMT_Tutorial\FMT_M01\Flood_Modeller\RES\FMT_M01_001.
[[File:Ief file.png|frameless|500x500px]]
<li>To the right of the Event Data box, click Add and select the '''FMT_Inflows.IED''' file in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' folder.</li>

<li>On the 'Times' tab, replace the simulation time parameters that were removed from TUFLOW. Enter the following parameters:</li>
*Run Type: Unsteady (Fixed Timestep)
*Start Time (hrs): 0
*Finish Time (hrs): 3
*Timestep (s):1
*Save Interval (s): 300.
[[File:Ief time.png|frameless|500x500px]]

<li> Add the 'Links' tab by clicking View> Tabs > Links. On the 'Links' tab, enter the following parameters:
*2-d Scheme: TUFLOW
*2-d Timestep: 2
*Check the box for ‘Perform corrective 1D timestep’
*2-d control file: full path to the '''FMT_M01_001.tcf''' from the '''\FMT_Tutorial\FMT_M01\TUFLOW\runs''' folder.
[[File:Ief tcf.png|frameless|500x500px]]
</li></li><li></li><li> Save the Scenario Data and run the Flood Modeller simulation. </li>{{Video|name=Setting up FMP IEF Simulation File.mp4 |width=1123}}</ul>

= Review Check Files =

=== Review Boundaries and 1D/2D Links ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M02_001_1d_to_2d_check
*FMT_M02_001_sac_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. In this case it should show the HX boundaries that have been digitised along the river banks.

The _sac_check layer highlights the lowest 2d cells within the SA boundary polygon to which inflow is first distributed.

=== Review Bank Elevations ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M01_001_zln_zpt_check_P

The _zln_zpt_check layer highlights the cells whose elevations have been modified by z lines to represent the bank crests of the watercourse.

= Review the Results =
Instructions for viewing the TUFLOW mesh (XMDF) and 1D time series (.tpc) outputs are provided in [[Tutorial_M01_Results_QGIS | Module 1]] and [[Tutorial_M03_Results_QGIS | Module 3.]] It is often useful to view 1D Flood Modeller results alongside 2D TUFLOW map outputs. The Flood Modeller results can be opened in QGIS with the TUFLOW Viewer plugin, together with the TUFLOW mesh results, by following the linked instructions. Alternatively, the TUFLOW mesh results can be loaded directly into the Flood Modeller Pro interface.

The video below demonstrates both methods:
*[[TUFLOW Viewer - Load Results - Time Series FM|Loading Flood Modeller 1D results]] in QGIS using the TUFLOW Viewer plugin.
*Loading TUFLOW mesh results in Flood Modeller Pro.
{{Video|name=Viewing Results in Flood Modeller and TUFLOW.mp4.mp4 |width=1123}}

= Troubleshooting =

=== Troubleshooting for HPC Simulation ===

If the following error message is encountered when running the TUFLOW HPC model:

<pre>ERROR 3999 - ptx file version mismatch
</pre>

If using the 2023-03-AA release or later up to, but not including, the 2026.0.0 release , please ensure that the four TUFLOW kernel files below have been transferred from your TUFLOW engine folder into your Flood Modeller "bin" folder.

*hpcKernels_nSP.ptx
*hpcKernels_nDP.ptx
*qpcKernels_nSP.ptx
*qpcKernels_nDP.ptx
If using the 2026.0.0 release or later, please ensure that the four TUFLOW fatbin container files listed below have been transferred from your TUFLOW engine folder into your Flood Modeller "bin" folder.

* hpcKernels_nDP.fatbin
* hpcKernels_nSP.fatbin
* qpcKernels_nDP.fatbin
* qpcKernels_nSP.fatbin

=== Troubleshooting for GPU Simulation ===
If the following error is encountered when running the TUFLOW HPC model using GPU hardware: :
<pre>TUFLOW GPU: Interrogating CUDA enabled GPUs …
TUFLOW GPU: Error: Non-CUDA Success Code returned
</pre>
or
<pre>ERROR 2785 - No GPU devices found, enabled or compatible.
</pre>
Please try the following steps:
<ol>
<li> Check if the GPU card is an NVIDIA GPU card. Currently, TUFLOW does not run on AMD type GPU.
<li> Check if the NVIDIA GPU card is CUDA enabled and whether the latest drivers are installed (see [[GPU_Setup |GPU Setup)]].
</ol>If an issue not described above is encountered, an email should be sent to [mailto:support@tuflow.com support@tuflow.com]. 

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model| Back to Tutorial Introduction Main Page]]
}}

Running linked Flood Modeller - TUFLOW Models

2026-03-30T13:33:57Z

RussellGardner: /* Flood Modeller-TUFLOW HPC/Quadtree */

==Introduction==
There are several different ways to run a linked Flood Modeller-TUFLOW or ISIS-TUFLOW model. 
This wiki page is intended to guide the user through the main methods of installing the link correctly and provide information on troubleshooting. 
Other resources for installation help include:
*[https://wiki.tuflow.com/index.php?title=TUFLOW_Licensing Installing a TUFLOW dongle]
*[https://wiki.tuflow.com/index.php?title=Running_TUFLOW Running a TUFLOW Model]
*[https://help.floodmodeller.com/floodmodeller/ Installing Flood Modeller]
*[https://help.floodmodeller.com/isis/ISIS.htm Installing ISIS (for backwards compatibility)]

Licensing considerations for running linked models have not been considered in this section. It was been assumed that the User has purchased the Flood Modeller-TUFLOW link module or is making use of the free versions.

==Methods to Run Linked Flood Modeller-TUFLOW models==
The four main methods for installing Flood Modeller and TUFLOW to run linked models are detailed below.
It is assumed for all methods that Flood Modeller has already been installed and TUFLOW has been downloaded.

===Set the TUFLOW Engine File Location in the Flood Modeller Interface===
Using the Flood Modeller interface to set the location of the TUFLOW engine files for the TUFLOW build you want to use, is the simplest approach to linking Flood Modeller and TUFLOW and does not duplicate files. This method is recommended if it is expected that the same versions of Flood Modeller and TUFLOW will be used consistently when running linked models.
 

1) Open the Flood Modeller software and in the 'Home' tab select the 'General' option. 
[[file:FM Home Tab.png|500px]] 

2) Select the 'Project Settings' sub-menu and within the TUFLOW Engine File Location choose to browse to the version of TUFLOW that you would like to link Flood Modeller to. Choose 'Open' and then 'OK'. 
[[file:FM TUFLOW Linking.png|500px]] 

3) Save the changes that you have made to the setup. This will update the settings file (formed.ini).

4) Restart Flood Modeller to effect the revised setting.

4) The linked model can then be run by opening the .ief file within the Flood Modeller Interface and clicking Run. 

===Set an Environment Variable===
Setting TUFLOW as an environment variable allows for simple installation and minimises duplication of files. This method is recommended if it is expected that the same versions of Flood Modeller and TUFLOW will be used consistently when running linked models.
 
1) Click on the start button in windows and open the Control Panel. In the Control Panel, navigate to System. 
[[file:control_panel.png|800px]] 
2) Click on Advanced Systems Settings. In the Advanced tab, click Environment Variables. 
[[file:Adv_Sys_Set.png|800px]] 
3) Under System Variables, click on the Path Variable and select Edit. 
In the dialog box, under Variable value, add a semi-colon after the current text and then the full file path to the location of the TUFLOW executable. 
4) The linked model may be run by opening the .ief file within the Flood Modeller Interface and clicking Run. 
[[file:env_var.png|800px]]

===Batch File===
This method allows the user the flexibility to simulate models using different version of Flood Modeller and TUFLOW on the same computer. 
After setting up this method the model is run through a batch file. The benefit of this method is that it allows for the running of multiple simulations. Later versions of Flood Modeller have a Batch run facility which can be used for this purpose. 
1) Using a file explorer, navigate to the location of the TUFLOW executable files. Copy all of the files either within the 'w32' folder or 'w64' folder depending on whether the 32 bit or 64 bit version of Flood Modeller has been installed on the computer. 
[[file:tuflow_download_files.png|500px]] 
2) Navigate to the location on the local drive where Flood Modeller has been installed. In this case, it is ''C:\Program Files\Flood Modeller'' although your path may differ depending on your system and installation. 
Paste the copied TUFLOW files into the ''bin'' folder. If asked, copy and replace the files. 
3) To set up this method for multiple versions of Flood Modeller and TUFLOW: 
* Create an empty folder and appropriately rename it to denote the versions of Flood Modeller and TUFLOW.
* Copy the entirety of the 'bin' folder from the version of Flood Modeller that you wish to use.
* Paste this 'bin' folder inside the newly created folder. 
* Copy and paste in all TUFLOW executable files from the version that you wish to use inside the 'bin' folder. Remember to ensure either the 32-bit or 64-bit executables are copied. These need to be compatible with the version of Flood Modeller used.

[[File:Diff TF versions.JPG]]
 

To run linked Flood Modeller-TUFLOW models with this method, create a [[Run_TUFLOW_From_a_Batch-file | batch file]]. 
* In a text editor, paste the path to the Flood Modeller executable file (ISISf32.exe for single precision and ISISf32_DoubleP.exe for double precision) and the name of the .ief file. It may be necessary to include the filepath if the .ief file is not saved in the same folder as the batch file.
* Add the optional batch switch '-sd'. This is useful when running multiple simulations as it allows for the simulation to automatically shutdown on completion removing the need for any user intervention.
* Double click on the batch file in a file explorer to start the simulation.
[[File:FMT run batch.PNG|700px]] 

===Flood Modeller Batch Runs===
The Flood Modeller batch run functionality can be used to set up multiple batch runs of Flood Modeller-TUFLOW linked models. 
Refer to the following guidance document on the Flood Modeller [https://help.floodmodeller.com/docs/the-batch-runner-2 website] for further information 

==Using TUFLOW Events and Scenarios when Running Linked Models ==
The Events and Scenarios feature within TUFLOW can be used when running linked models. Further information on this feature may be found within [https://www.tuflow.com/Download/Presentations/2012/2012%20Aust%20Workshops%20-%20TUFLOW%20Multiple%20Events%20and%20Scenarios.pdf this presentation] and in the [[TUFLOW_Example_Models | TUFLOW example models]]. 
 
Each unique Flood Modeller - TUFLOW simulation will still require its own .ief file. However, each of these .ief files may refer to the same TUFLOW .tcf control file. The TUFLOW Event or Scenario is specified within the 'Run Options' Section of the 'Links' tab within the .ief file. 

In the below example, the .ief file is named 'my_model_0100F_EXG_002.ief'. It references a TUFLOW .tcf file named 'my_model_~e1~_~s1~_002.tcf'. 
By adding '-e1 0100F -s1 EXG' to the 'Run Options' box, the '0100F' event and the 'EXG' scenario is selected by TUFLOW. 
 
[[File:FMT EventsScenarios.PNG]]

==Single vs Double Precision and 32-Bit vs 64-Bit==
A common error encountered when compiling linked Flood Modeller-TUFLOW models is inconsistency between versions. These errors will typically cause the model run to fail before the simulation has commenced. 
 
There are two factors to getting this correct: 
1) [https://www.computerhope.com/issues/ch001498.htm 32-Bit or 64-Bit] versions 
Both TUFLOW and Flood Modeller have both 32-Bit and 64-Bit versions. 
When installing Flood Modeller, the user has the option to selection which version to install. As TUFLOW does not require installation, the option of selecting 32-Bit or 64-Bit occurs when choosing which executable to simulate the model. It is important that the 32 or 64 bit versions match. This can be verified by viewing the Flood Modeller diagnositics file (.zzd) and the TUFLOW log file (.tlf). 

2) [https://www.tuflow.com/forum/index.php?/topic/821-single-precision-vs-double-precision/ Single vs Double Precision] 
Both TUFLOW and Flood Modeller have Single and Double precision versions. In short, these refer to the number of decimal points used when carrying out the calculations. Depending on the model, one version may be preferred over the other. CH2M have provided some further guidance on [https://www.floodmodeller.com/en-gb/news/articles/2013/6/double-precision-single-precision-and-batching-konrad-adams-isis-and-tuflow-specialist/ this page] . 
 

Whichever precision version is selected when simulation a linked Flood Modeller -TUFLOW model, it is important to ensure consistency between the packages. This can be verified by viewing the Flood Modeller diagnositics file (.zzd) and the TUFLOW log file (.tlf). 
[[File:Version_check.png]]

==Flood Modeller-TUFLOW HPC/Quadtree==

Flood Modeller is compatible with TUFLOW Classic, TUFLOW HPC and TUFLOW Quadtree. In order to use TUFLOW HPC, Flood Modeller 4.6 or later should be used. It is recommended that TUFLOW 2018-03-AE or later is used. This allows connectivity between Flood Modeller, TUFLOW HPC and TUFLOW 1D (aka ESTRY). The benefit of using TUFLOW HPC is to allow the 2D calculations to utilise GPU card technology for significant reductions in simulation time compared to TUFLOW Classic. The following section [[Running linked Flood Modeller - TUFLOW Models#Flood Modeller-TUFLOW Benchmarking including TUFLOW HPC|here]] provides some benchmarking tests demonstrating this.

In order to use TUFLOW Quadtree, then Flood Modeller 5 or later is required, which should be used in conjunction with TUFLOW 2020-01-AB or later.

When using Flood Modeller and TUFLOW HPC/Quadtree, it is important that the Flood Modeller folder must contain copies of four TUFLOW files. This folder is called the “bin” folder and is located (by default) in “C:\Program Files\Flood Modeller”. For TUFLOW versions 2020-10-AF and earlier, the four required TUFLOW files are called:

* kernels_nSP.ptx
* kernels_nDP.ptx
* QPC_kernels_nDP.ptx
* QPC_kernels_nDP.ptx

If using the 2023-03-AA release or later up to, but not including, the 2026.0.0 release, the names of the kernels have changed and are now:

* hpcKernels_nSP.ptx
* hpcKernels_nDP.ptx
* qpcKernels_nSP.ptx
* qpcKernels_nDP.ptx
If using the 2026.0.0 release or later, the .ptx kernels have been replaced by .fatbin container files, which are named:

* hpcKernels_nDP.fatbin
* hpcKernels_nSP.fatbin
* qpcKernels_nDP.fatbin
* qpcKernels_nSP.fatbin

The Flood Modeller installation includes versions of these files that should be compatible with the latest version of TUFLOW available at the time of the Flood Modeller release. If you need to use a later release of TUFLOW or if you find that the link in a Flood Modeller-TUFLOW coupled model is failing with a [[TUFLOW Message 3999|3999 error]] message (and an error description of 'ptx file file version mismatch' in the hpc.tlf), then browse to your TUFLOW engine folder, and copy the above four files and then paste them into your Flood Modeller bin folder (replacing the files there). If wanting to use the 2023-03-AA release or later, please ensure the relevant kernels are in the Flood Modeller Bin folder and any other TUFLOW .ptx files (ie, kernels_nSP.ptx, kernels_nDP.ptx) are removed. If wanting to use the 2026.0.0 release or later, please ensure the relevant .fatbin files have been transferred to the Flood Modeller Bin folder.

== Troubleshooting ==

When switching between different build versions of TUFLOW it is possible to receive errors relating to the linking of the software. This is can be due to incorrect linking files being called when the link is established. If using TUFLOW HPC/Quadtree refer to the section above. Other linking issues can result in the TUFLOW initialisation phase failing with no specific error or warning. These are most commonly a symptom of mismatched files within TUFLOW and in the Flood Modeller Bin Folder.

If a linked model is failing, with the last message in the .tlf being: 

<tt>Attempting to create XMDF file </tt> <tt>"\\Example_path\Model.xmdf"</tt> 

Navigate to the specific TUFLOW Build that is being used, locate the following files below and copy and paste these into the Flood Modeller Bin folder: 

*'''hdf5.dll'''
*'''hdf5_hl.dll'''

Should this error continue to happen it is recommended re-installing Flood Modeller or contacting [mailto:support@tuflow.com support@tuflow.com] attaching the .tlf and also informing which build versions of both software packages is being used.

In some instances, when running from Flood Modeller, a linked Flood Modeller-TUFLOW model will fail during the model initialisation phase without saving a TLF file. In such an instance it is worth testing the TUFLOW model by running a TUFLOW only model (or using the Test Model functionality. Please see here: [https://wiki.tuflow.com/index.php?title=Run_TUFLOW_From_a_Batch-file#Testing_a_simulation Testing a simulation]). The pre-processing will ultimately fail as it is not being run in conjunction with the Flood Modeller model, but it will flag up any input errors which occur within the TUFLOW model and result in the TLF not being written.

If you have further queries or issues it is recommended contacting [mailto:support@tuflow.com support@tuflow.com].

==Flood Modeller-TUFLOW Benchmarking including TUFLOW HPC==

The following page provides information on some linked Flood Modeller-TUFLOW Benchmarking on different PC's utilising TUFLOW Classic, TUFLOW HPC on multiple CPU and TUFLOW HPC on a GPU Card.

[[Flood Modeller-TUFLOW Benchmarking|Flood Modeller-TUFLOW Benchmarking]].

Flood Modeller Tutorial Model

2026-02-06T13:06:08Z

RussellGardner:

=Introduction=
The objective of the Flood Modeller - TUFLOW modules is to demonstrate how TUFLOW links to the external Flood Modeller 1D scheme and the methods available to create this link. They are designed to supplement existing documentation and assume prior knowledge of both Flood Modeller and TUFLOW software packages.

These modules were developed by BMT in collaboration with Jacobs. Comments, requests and feedback can be sent to [mailto:support@tuflow.com support@tuflow.com].

=Requirements and Downloads=
Both TUFLOW and Flood Modeller have modest system requirements for small models such as those used in these modules. Larger and more complex models, however, may require higher hardware specifications, particularly memory (RAM). The tutorial models are intentionally small to ensure quick simulation and load times, and should run on any modern PC or laptop capable of running Windows 10 or later.

TUFLOW models typically require access to a GIS package, a text editor, Microsoft Excel and a results viewer to build, review and visualise a model. A list of compatible packages is available on the TUFLOW Wiki. Flood Modeller can also be used as a graphical user interface for creating and editing GIS layers in a TUFLOW model, as well as for visualising results.

Instructions for Flood Modeller - TUFLOW modules are provided using the following GIS file formats:

* '''QGIS - SHP'''

* '''QGIS - GPKG'''

{| class="wikitable" width="75%"

! style="background-color:#005581; font-weight:bold; color:white;"| Requirement
! style="background-color:#005581; font-weight:bold; color:white;" | Brief Description
! style="background-color:#005581; font-weight:bold; color:white;" | Download
|-

| '''TUFLOW''' || TUFLOW is a computer program for simulating depth-averaged, one dimensional free-surface flows such as occurs from floods and tides, with the 2D solution occurring over a regular grid of square elements. 

It is commonly used in the UK and Ireland, Australia and the United States for the modelling of surface waters, river systems and pipe networks. 

It is recommended to always use the latest release version of TUFLOW. 

This tutorial model does not require a TUFLOW licence. 

This tutorial is set up to use a NVIDIA GPU card. If this is not available, CPU can be specfied within the [https://docs.tuflow.com/classic-hpc/manual/2025.2/TCFCommands-1.html#tcfHardware Hardware] command. 
||The TUFLOW executable is provided within the [https://wiki.tuflow.com/Tutorial_Introduction#Module_Data Tutorial Dataset].
|-

|'''Flood Modeller'''|| Flood Modeller (previously known as ISIS) is a commercial flood modelling package developed by Jacobs for simulating depth-averaged one and two dimensional free surface flows. It is primarily used for the simulation of river channels and is widely used within the UK and Ireland. This tutorial model will only leverage Flood Modeller’s 1D Solver. 
TUFLOW 1D and 2D domains can be dynamically linked to the 1D domain of Flood Modeller. Flood Modeller is not included within the TUFLOW executable and must be downloaded separately. 

Unlike TUFLOW Flood Modeller has a standalone Graphical User Interface which can be used to build networks, run models, and visualise results.

It is recommended that TUFLOW 2023-03-AA or later is used in conjunction with Flood Modeller Version 5 or later. [https://docs.tuflow.com/classic-hpc/manual/2025.2/OneD2DLinkingFM-2.html#fig:fig-FMTUFLOWVersionCompatability Figure 10.15] of the [https://docs.tuflow.com/classic-hpc/manual/2025.2/ 2025 TUFLOW manual] provides a list of compatibility between recent Flood Modeller and TUFLOW versions. 

For Flood Modeller Version 5 or later a Standard, Professional, or Unlimited Edition of Flood Modeller Pro is required to open and run the tutorial model.
||[https://www.floodmodeller.com/downloads/ Latest 64-bit version of Flood Modeller]. 
|-
| '''QGIS''' QGIS TUFLOW plugin || A Geographic Information System (GIS) used to build models and view results. This tutorial was developed with QGIS 3.20. It is recommended to have QGIS 3.20 or later to ensure compatibility with TUFLOW plugin latest features. 

The TUFLOW plugin includes numerous tools to increase workflow efficiency. 

||[https://qgis.org/download/ Latest 64-bit version of QGIS]. 

[[TUFLOW_QGIS_Plugin| QGIS TUFLOW Plugin Installation]].
|-
| '''NotePad++''' Syntax Highlighting || A text editor is required for creation of the TUFLOW input files. This tutorial was developed with NotePad++. Ideally a text editor should be able to: 
*Colour code the TUFLOW control files;
*Open other files from the active control file; and
*Launch a TUFLOW simulation. 
TUFLOW colour coding can be enabled using syntax highlighting.
|| [https://notepad-plus-plus.org/downloads/ Latest 64-bit version of Notepad++]. 

[https://downloads.tuflow.com/_archive/Miscellaneous/NPP_TUFLOW_Syntax_Highlighting.zip TUFLOW syntax highlighting for Notepad++]. For instructions on configuring Notepad++ for TUFLOW modelling, see [[NotepadPlusPlus_Tips |Notepad++ tips]].
|-
| '''Microsoft Excel''' || A spreadsheet software is required for working with tabular data and .csv files. This tutorial has been created in Excel. ||
|}
=Module Data=
To build the tutorial model, download one of the datasets below. This includes a digital elevation model (DEM), aerial photography, background model data for the tutorial model and a working version of the model. There are two formats available, Shapefile and GeoPackage. The GeoPackage format has been supported since the TUFLOW 2023-03 Release, for tips on its use see [https://wiki.tuflow.com/GeoPackage_Tips GeoPackage Tips].

*[https://downloads.tuflow.com/TUFLOW/Wiki_Tute_Models/QGIS_SHP_FMP_Tut_Model.zip QGIS SHP Download]
*[https://downloads.tuflow.com/TUFLOW/Wiki_Tute_Models/QGIS_GPKG_FMP_Tut_Model.zip QGIS GPKG Download]

If would you like to download the tutorial model datasets for ArcGIS or MapInfo, these can be found on the [[Flood_Modeller_Tutorial_Model_Archive | Archive Page]].

=Recommended Reading=
The aim of this tutorial is to demonstrate the steps undertaken to build, review and visualise the results of a linked Flood Modeller – TUFLOW model. It assumes that the user has a good understanding of both the 1D component of Flood Modeller and the 1D and 2D components of TUFLOW. The following resources may be of use:
*[[Tutorial_Introduction |TUFLOW Tutorial Model]]
*[https://docs.tuflow.com/classic-hpc/manual/2025.2/ TUFLOW Classic / HPC User Manual]
*[https://help.floodmodeller.com/docs/getting-started-with-1d-river-modelling Flood Modeller 1D Quick Start Guide]
*[https://help.floodmodeller.com/docs/technical-reference Flood Modeller Technical Reference]

=Modules=
The tutorial is presented over a series of modules, with each module offering the opportunity to run the model and review the results. Each of the modules builds upon the previous iteration with models developed in the previous module made available.

New users are advised to undertake the modules in sequence, whilst more experienced users can skip to modules containing specific features of interest. Results and check files are not included to keep the size of the download file manageable, but can be generated through the running of the simulations. The folder should be placed in a location with write permissions. The first tutorial module introduces the user to the linking of a TUFLOW 2D domain to a 1D Flood Modeller model. From this tutorial you will learn how to link an existing Flood Modeller 1D model to a TUFLOW 2D domain. This tutorial is ideal for those starting to learn how to link Flood Modeller and TUFLOW.

:*[[ Flood_Modeller_Tutorial_Module01 | Flood Modeller Module 1]] - Linking Flood Modeller to TUFLOW

The second tutorial demonstrates the linking of an ESTRY pipe network to an existing Flood Modeller – TUFLOW linked model. From this tutorial you will learn how to add a 1D pipe network and connect it to the representation of the watercourse created in Flood Modeller and link it to the TUFLOW representation of the floodplain created as part of the first tutorial. The second tutorial is ideal for those who would like to learn more about the interaction of TUFLOW with Flood Modeller including the simulation of fully integrated drainage systems.
:*[[ Flood_Modeller_Tutorial_Module02 | Flood Modeller Module 2]] - Linking Flood Modeller to ESTRY

 
{{Tips Navigation
|uplink=[[Main_Page| Back to Main Page]]
}}

Green-Ampt Infiltration Parameters

2026-01-26T09:47:55Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 11, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023 v2.jpg.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 12 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Green-Ampt Infiltration Parameters

2026-01-20T13:36:16Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023 v2.jpg.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 12 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Green-Ampt Infiltration Parameters

2026-01-20T13:35:02Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023 v2.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 12 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

File:Init moisture post 2023 v2.jpg.jpg

2026-01-20T13:34:29Z

RussellGardner:

n/a

Green-Ampt Infiltration Parameters

2026-01-20T13:26:19Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 12 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Green-Ampt Infiltration Parameters

2026-01-20T13:18:44Z

RussellGardner: /* In built USDA soil type */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 12 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 12: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Green-Ampt Infiltration Parameters

2026-01-20T13:18:23Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 11 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Green-Ampt Infiltration Parameters

2026-01-20T13:17:54Z

RussellGardner: /* Initial Moisture */

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

The three initial moisture sensitivity tests have been undertaken with the Green-Ampt method using both a pre-2023 release of TUFLOW and a post-2023 release of TUFLOW. Figure 9 shows how variations in the initial moisture affect the simulated cumulative infiltration, whereas Figures 10 and 11 show the effects of varying the initial moisture on flows at the catchment outlet when using the pre-2023 and post-2023 releases of TUFLOW. As the initial moisture is increased at the beginning of your simulation, there is less infiltration (as you are closer to soil capacity) and more runoff, causing the catchment outflows to exhibit a faster response to rainfall upstream. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant. In the examples shown here, the catchment outflows, as visible in Figures 10 and 12, show a higher responsiveness to variations in initial moisture at the beginning of the simulations, and attain higher peak values, when using the post-2023 TUFLOW releases.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in pre-2023 release of TUFLOW.'''
[[File:Init moisture post 2023.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model in post-2023 release of TUFLOW.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 11 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

File:Init moisture post 2023.jpg

2026-01-20T13:17:10Z

RussellGardner:

n/a

Green-Ampt Infiltration Parameters

2026-01-20T12:50:55Z

RussellGardner:

== Introduction ==
TUFLOW provides several methods for modelling infiltration from the 2D surface into the sub-surface, including Green-Ampt, Horton, and Initial Loss/Continuing Loss. These methods are used to simulate hydrological losses, particularly when rainfall is applied directly to the 2D surface and runoff is generated.

The choice of infiltration method and its parameters is an important calibration factor and should be adjusted to match observed flow data. This is especially relevant for whole of catchment modelling, where infiltration is the main way hydrological losses are represented. This page describes the Green-Ampt infiltration parameters and their sensitivity.

== Green-Ampt Infiltration ==
The Green-Ampt approach varies the rate of infiltration over time based on the soil’s hydraulic conductivity, suction, porosity and initial moisture content. The method assumes that as water begins to infiltrate the soil, a line is developed differentiating between the ‘dry’ soil with moisture content θi and the ‘wet’ soil (with moisture content equal to the porosity of the soil η). As the infiltrated water continues to move through the soil profile in a vertical direction, the soil moisture changes instantly from the initial content to a saturated state. This concept is shown schematically in Figure 1.

Note: The Green-Ampt approach is appropriate for simulating single rainfall events where evapotranspiration and gravity-driven drainage are not significant. The 2023-03 release introduced functionality in TUFLOW HPC to allow for horizontal movement of soil water, enabling long-term simulations with multiple rainfall events. To support this, a change was implemented in the Green-Ampt equation to account for changing initial soil moisture and cumulative infiltration over time. For further details, see Section 7.3.7.1.1 Green-Ampt (GA) in the [https://docs.tuflow.com/classic-hpc/manual/2025.1/TwoD-Domains-1.html#GA-5 TUFLOW Manual].

[[File:Fig_1_GA_Model.png|300px|Figure 1 Green-Ampt Model Concept]] 

'''Figure 1 Green-Ampt Model Concept''' 
''Figure courtesy of University of Texas''

 
The basic form of the Green-Ampt equation is expressed as follows: 
[[File:Basic_ga_equation.png|200px]] 

 
Where: 
:''t'' is time 
:K is the saturated hydraulic conductivity 
:∆''θ'' is defined as the soil capacity (the difference between the saturated and initial moisture content) 
:''φ'' is the soil suction head 
:h0 is the depth of ponded water 
:F(t) is the cumulative infiltration calculated from: 
[[File:Accumulative_infil.png|350px]] 

United States Department of Agriculture (USDA) soil types have been hardwired into TUFLOW and are presented in Table 1 along with the soil parameters. Alternatively, it is possible to define a customised soil type by specifying user defined values within the tsoilf. 
 
'''Table 1 USDA Soil types for the Green-Ampt Infiltration Method (from Rawls, W, J, Brakesiek & Miller, N, 1983, ‘Green-Ampt infiltration parameters from soils data’, Journal of Hydraulic Engineering, vol 109, 62-71.)''' 
{| class="wikitable "
| '''USDA Soil Type''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Clay''' || 316.3 || 0.3 || 0.385
|-
| '''Silty Clay''' || 292.2 || 0.5 || 0.423
|-
| '''Sandy Clay''' || 239 || 0.6 || 0.321
|-
| '''Clay Loam''' || 208.8 || 1 || 0.309
|-
| '''Silty Clay Loam''' || 273 || 1 || 0.432
|-
| '''Sandy Clay Loam''' || 218.5 || 1.5 || 0.33
|-
| '''Silt Loam''' || 166.8 || 3.4 || 0.486
|-
| '''Loam''' || 88.9 || 7.6 || 0.434
|-
| '''Sandy Loam''' || 110.1 || 10.9 || 0.412
|-
| '''Loamy Sand''' || 61.3 || 29.9 || 0.401
|-
| '''Sand''' || 49.5 || 117.8 || 0.417
|}
 
Table 2 presents summary statistics for the Green-Ampt USDA Parameters and typical values. This provides a good indication of the typical ranges of the Green-Ampt parameter values. 
 
'''Table 2 USDA Summary Statistics for all Soil types for the Green-Ampt Infiltration Method''' 
{| class="wikitable "
| '''Stat''' || '''Suction (mm)''' || '''Hydraulic Conductivity (mm/hr)''' || '''Porosity (Fraction)'''
|-
| '''Min''' || 49.5 || 0.3 || 0.31
|-
| '''Max''' || 316.3 || 117.8 || 0.49
|-
| '''Mean''' || 184.04 || 15.86 || 0.4
|-
| '''SD''' || 94.82 || 34.92 || 0.05
|}
 
In order to help those undertaking real world calibration of TUFLOW models to observed data, a sensitivity analysis of the various parameters have been undertaken to show the effect of each Green-Ampt parameter in isolation. The comparison has been undertaken on a real-world whole catchment model of the Plynlimon catchment in mid-Wales. The model was run with a real rainfall event from 2015 with a temporal resolution of 30 minutes as shown in Figure 2. 
 

[[File:Fig2 GWY RF.png|600px|Figure 2: Plynlimon Rainfall|border]] 

'''Figure 2: Plynlimon Rainfall''' 

For the purposes of this sensitivity analysis of the parameters, a single soil type was used representing the general clay soil types that are present. 

== Green-Ampt Infiltration: User Parameters ==
Where the inbuilt USDA soil types are not used, the user can specify their own values for the Suction, Hydraulic Conductivity, Porosity and Initial Soil Moisture. What follows is a description of each parameter and the sensitivity to a low, medium and high value based on the USDA soil type summary values.

=== Capillary Suction Head ===
The suction head, represented in millimeters, is the capillary attraction on the soil voids. It is large for fine grain soils such as clays and smaller for sandy soils. To test the sensitivity of the simulated runoff at a gauged location, a low (49.5mm), mid representing the mean (184.4mm) and high (316.3mm) value of the suction head parameter were used with other parameters representing a clay soil (soil type 1). 
The larger the value of the capillary suction head, the more capillary action that is achieved and the amount of infiltration that takes place. This is shown by the increase in cumulative infiltration in the graph below with a greater cumulative infiltration for the increase in the suction head. 

[[File:Fig4 sens to suction.png|600px|Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 3: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Capillary Suction Head parameter in the Green-Ampt infiltration model.''' 
 
As a consequence of this, there is a less runoff generated as shown in Figure 4. As can be seen, the model is not particularly sensitive to the suction head parameter and this fits with observations made within the literature from other similar studies. 
 

[[File:Suction Head.jpg|border|760x760px|Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.]] 

'''Figure 4: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Suction head parameter in the Green-Ampt infiltration model.''' 
 
It can also be seen that the higher the suction head value that the longer it takes the hydrograph to start rising, with the high suction head scenario less responsive to the rainfall.

=== Saturated Hydraulic Conductivity ===
The saturated hydraulic conductivity, measured in millimetres per hour, represents how easily water can travel through soil when fully saturated. In the Horton infiltration model, this value corresponds to the limiting infiltration rate. Hydraulic conductivity is typically high for sandy soils and low for compact clays.

In the sensitivity testing, the focus was on clay soils, which generally have low conductivity values. Three scenarios were initially tested: low (0.3 mm/hr), mid (15.86 mm/hr), and high (117.8 mm/hr). However, the mid and high values resulted in such high infiltration that no surface runoff was produced, leading to zero simulated flow at the downstream gauge location. As expected, increasing hydraulic conductivity leads to more infiltration and less runoff, a relationship well documented in Green-Ampt-based infiltration modelling.

To improve the analysis, it is recommended that the model be rerun using a refined range of lower conductivity values that still allow some runoff, such as 0.3, 1.0, 3.4, and 7.6 mm/hr. This would provide a more meaningful understanding of the parameter sensitivity while preserving realistic surface runoff behaviour. 
 

[[File:Hydraulic Conductivity.jpg|border|760x760px|Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.]] 

'''Figure 5: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''' 
 

[[File:Fig7 hydroconduct.png|600px|Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 6: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''

=== Porosity ===
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation. Sandy soils tend to have lower porosities than clay soils, but drain to lower moisture contents between rainfall events because water is not held as strongly in the soil pores. Therefore, values of porosity tend to be higher for sandy soils when compared to clay soils. As shown in figure 7, the higher the porosity value, then the less runoff that is generated due to increased infiltration although the model is not particular sensitive to the porosity value. 
 

[[File:Porosity.jpg|border|760x760px|Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]] 

'''Figure 7: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 
 

[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.|border]] 

'''Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.''' 

=== Initial Moisture ===
The initial moisture value represents the fraction of the soil that is initially wet. As both initial moisture and porosity are expressed as fractions, the soil capacity is defined as the difference between them both. As such, the initial moisture should not exceed the porosity otherwise soil capacity will be set to zero with no infiltration occurring for that soil type. A [[TUFLOW Message 2508 |2508 WARNING]] is issued if this is the case. 

In pre-2023 releases of TUFLOW, a single variable storage capacity was calculated by subtracting the initial moisture fraction from the porosity, in order to reduce memory requirements. However, in TUFLOW releases 2023 and onwards, the soil porosity and initial moisture must be stored separately to allow the soil to drain correctly when using the interflow functionality. This updated approach requires that a soil thickness be specified to calculate the soil depth. If a soil thickness is not specified when using the updated approach, an infinite soil depth is assumed for each layer and therefore different initial moisture fractions no longer have an effect on modelled results. These two approaches can generate different results when using the Green-Ampt method.

As you increase initial moisture at the beginning of your simulation, you experience less infiltration (as you are closer to the soil capacity), therefore have more run-off and a quicker response. Figure 9 shows the degree of change to cumulative infiltration with varying initial moisture and the effect on the catchment can be seen in Figure 10. As the event progresses, soils become more saturated and the influence of the initial moisture parameter becomes less significant.

[[File:Init moisture F10.png|600px|Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.|border]] 
'''Figure 9: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.''' 
[[File:Initial moisture.jpg|border|760x760px|Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.]] 
'''Figure 10: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the initial moisture parameter in the Green-Ampt infiltration model.'''

=== Max Ponding Depth ===
The max ponding depth value is an optional value that can be used, if desired, to set a limit for the depth of ponded water (h0) value used in the Green-Ampt equation. The minimum of the water depth and the max ponding depth value is used as the h0 value. The default max ponding depth value is 0, to be consistent with the basic form of the Green-Ampt equation, as hydrology models do not necessarily have a depth calculated at cells.

This means, if using a max ponding depth (>0), infiltration rates will increase.

== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 11 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils do not show any runoff in this example as the rainfall applied directly to the mesh is all infiltrated. 
 
[[File:Soil Type.jpg|border|760x760px|Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.]] 
'''Figure 11: Sensitivity of simulated flow at the Cefn-Brwn gauge location in the Plynlimon Gwy catchment to the USDA soil type parameter in the Green-Ampt infiltration model.'''

== Summary ==
The Green-Ampt infiltration model is one of the infiltration methods available within TUFLOW. There is extensive literature on its application, including suggested parameter values for various soil types, though these are mostly based on soils in the United States.

Three main Green-Ampt parameters have been tested to assess the sensitivity of model outputs to parameter values and variations in initial soil moisture. The results show that the model is relatively insensitive to the porosity and suction head parameters. However, outputs show significant variations in runoff volume in response to changes in hydraulic conductivity.

As part of any calibration process, it is recommended that hydraulic conductivity and initial moisture content be prioritised during calibration. Hydraulic conductivity influences runoff volume throughout the event, while initial soil moisture mainly affects the early part of the simulation until soils become saturated and results converge.

==Acknowledgements==

The Plynlimon model contains data supplied by Natural Environment Research Council. The Plynlimon observed rain gauge and flow data was provided by the Centre of Hydrology, Bangor. The model uses LiDAR data which is public sector information licensed under the Open Government Licence v3.0.

Flood Modeller Tutorial Module02

2026-01-08T10:44:09Z

RussellGardner: /* Flood Modeller Simulation Files */

= Introduction =
In this module, a proposed development is represented within an existing model by adding TUFLOW 1D pipe network elements, which are then linked with Flood Modeller Pro.

This will include:
* Modification of the floodplain topography through the creation of a 3D TIN surface.
* Revision of the land use.
* Addition of pipes and pits in ESTRY to represent the underground network.
* Linking of the pipe network in ESTRY with the Flood Modeller network.
* Introduction of an inflow into the pipe system.
* Addition of a river reach represented in ESTRY downstream of the Flood Modeller network.

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module02_Archive |Tutorial Module 02]].

===Define Elevations (Building a TIN)===
The GIS layers necessary to modify the ground elevations to represent the proposed development are provided. This part of the tutorial demonstrates how a TIN is created from these GIS layers. The GIS defining the road crest level is also updated. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Elevations | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Elevations | QGIS - GPKG]]

===Define Surface Roughness===
The GIS layers necessary to modify the land use areas affected by the proposed development are provided. This part of the tutorial demonstrates how to populate the layer attributes to assign Manning’s n roughness values to each land use. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Roughness | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Roughness | QGIS - GPKG]]

===Define Pipe Network===
This part of the module creates the GIS layers that define the sub-surface pipe network. The inlets and pits of the pipe network are linked to the 2D domain. The pit inlet database is also created, linking the GIS layers to depth-discharge curves. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Pipe_Network | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Pipe_Network | QGIS - GPKG]]

===Define Boundary Conditions===
This part of the module demonstrates how an inflow can be applied directly to the pits of the pipe network. A GIS layer of the inflow boundary is provided. The existing Boundary Conditions Database is also modified to include these new inflows. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Boundary_Conditions | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Boundary_Conditions | QGIS - GPKG]]

==Flood Modeller 1D/ESTRY 1D Link==
This part of the module demonstrates how TUFLOW 1D (ESTRY) domains can be dynamically linked with Flood Modeller using "X1DH" and "X1DQ" links. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Flood Modeller1D/ESTRY 1D Link | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Flood Modeller1D/ESTRY 1D Link | QGIS - GPKG]]

The Flood Modeller 1D/ESTRY 1D link can be employed for a number of reasons, including:

* Inclusion of the pipe network and manhole modelling capabilities of ESTRY within a Flood Modeller – TUFLOW linked model (see [https://docs.tuflow.com/classic-hpc/manual/2025.1/DomainLinking-1.html#OneD2DLinkingFM-2 Section 10.5] of the TUFLOW Manual for more details).
* Extension of a Flood Modeller network within ESTRY to overcome Flood Modeller node licence limits.
* Representation of a steeper tributary in ESTRY which can then be connected to the main river represented in Flood Modeller.

Flood Modeller and TUFLOW (ESTRY) nodes are considered linked if an ESTRY node in a 1d_nwk layer and a Flood Modeller node in a [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNodes Read GIS X1D Nodes] or [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNetwork Read GIS X1D Network] layer are snapped together, or are within the snap tolerance distance specified.

ESTRY nodes are automatically generated at the upstream and downstream extremities of an ESTRY link, so manual generation of a node is not mandatory. If no node is manually added, the Flood Modeller–ESTRY link is assumed to be an “X1DH” link. If an ESTRY node is manually generated, the ESTRY node can have a 1d_nwk layer Conn_1D_2D attribute of either “X1DH” or “X1DQ”.

An "X1DH" link means a Flood Modeller 1D water level is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a water level and ESTRY sends back a +/- flow to Flood Modeller). An ESTRY "X1DH" link (the default) is typically used where ESTRY discharges into a Flood Modeller network. The "X1DH" link is applied to the Flood Modeller 1D network as a lateral inflow. The Flood Modeller 1D node connected to the ESTRY node by an "X1DH" connection must not be the end node of a reach.

An "X1DQ" link means a Flood Modeller inflow/outflow is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a +/- flow and ESTRY sends back a water level). This is more appropriate where a Flood Modeller network terminates and flows into an ESTRY model. The Flood Modeller 1D node at the end of an "X1DQ" connection must be an HTBDY unit, although it is not necessary for the HTBDY unit to contain any boundary data as this data is overridden by the water levels provided by TUFLOW.

=Modify Simulation Control Files=
With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.
== TUFLOW Geometry Control File (TGC) ==

At this stage, the following changes will be made to the geometry:

* A 3D TIN is created to represent changes to the ground elevations.
* Two 2d_mat layers are added to represent changes to the land use at the location of the proposed development.

<ol>
<li>Open FMT_M01_001.tgc in a text editor and save the file as FMT_M02_001.tgc.</li>

<li>Open FMT_M02_001.tgc.</li>

<li>Add the commands to modify the topography to represent the proposed development. These commands should be placed after the <tt>Read GIS Z Shape</tt> line:

 '''QGIS - SHP'''
 <tt>Create TIN Zpts WRITE TIN == gis\2d_ztin_fmt_m02_development_001_R.shp | gis\2d_ztin_fmt_m02_development_001_P.shp</tt>

 '''QGIS - GPKG'''
 <tt>Create TIN Zpts WRITE TIN == 2d_ztin_fmt_m02_development_001_R | 2d_ztin_fmt_m02_development_001_P</tt>

 The <tt>Create TIN Zpts WRITE TIN</tt> command creates and writes a .2dm mesh file to the same location as the GIS layer (in this case the TUFLOW\model\gis folder). The .2dm TIN can be viewed, checked, and modified in QGIS. It can then be read into the model directly using the <tt>Read TIN Zpts</tt> command for subsequent model simulations.

The 2d_mat layers created in this module build upon the existing commands that modify roughness. The new layers overwrite the existing layers at the location of the proposed development. This process of layering provides a powerful tool in TUFLOW that minimises data duplication and offers a means of quality control. The commands reading in the new 2d_mat layers must be placed after the existing commands.

 '''QGIS - SHP'''
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_001_R.shp</tt>
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_buildings_001_R.shp</tt>

 '''QGIS - GPKG'''
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_001_R</tt>
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_buildings_001_R</tt>
</li>
 
<li>Save the file. The TGC is now ready to be used.</li>
</ol>

== ESTRY Control File (ECF) ==
At this stage, the following changes are made to the ECF file:
* A 1d_nwk layer is created to represent the culverts of the proposed pipe network.
* A 1d_nwk layer is created to represent the pits of the proposed pipe network.
* A pit inlet database is created to link depth-discharge curves to the pit inlet type.

<ol>
<li>Open FMT_M01_001.ecf in your text editor. Save the file as FMT_M02_001.ecf.</li>
<li>Open FMT_M02_001.ecf </li>
<li>Add the following commands at the bottom of the file as follows:
<div>
'''QGIS - SHP''' 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pipes_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pits_001_P.shp 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Channels_001_L.shp 
<tt>Read GIS Table Links</tt> <tt>==</tt> xs\1d_xs_FMT_M02_Creek_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwke_X1DQ_P.shp 
<tt>Read GIS BC</tt> <tt>==</tt> gis\1d_BC_FMT_M02_001_P.shp 
'''QGIS - GPKG''' 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pipes_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pits_001_P 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Channels_001_L 
<tt>Read GIS Table Links</tt> <tt>==</tt> 1d_xs_FMT_M02_Creek_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwke_X1DQ_P 
<tt>Read GIS BC</tt> <tt>==</tt> 1d_BC_FMT_M02_001_P
</div>
</li>
<li value="4">Save the file. The ECF file is now ready to be used.</li>
</ol>

== TUFLOW Boundary Control File (TBC) ==
A 2d_sa layer will be created to define inflows into the pipe network and referenced in the TBC file.
<ol>
<li>Open FMT_M01_001.tbc in a text editor and save it as FMT_M02_001.tbc.</li>
<li>Insert the following commands after the existing <tt>Read GIS SA</tt><tt> ==</tt> mi\2d_sa_M01_002_R.shp command:</li>
'''QGIS - SHP''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> gis\2d_sa_FMT_M02_001_R.shp 
'''QGIS - GPKG''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> 2d_sa_FMT_M02_001_R 
<li>Save the file. The TBC file is now ready to be used.</li>
</ol>

==TUFLOW Control File (TCF)==

We will need to create a new tcf file that references the new tgc, ecf and tbc files.
<ol>
<li>Open FMT_M01_001.tcf and save as FMT_M02_DEV_001.tcf.
Update the following commands:
:<tt>Geometry Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tgc
:<tt>ESTRY Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.ecf
:<tt>BC Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tbc
<li>We have also created a new bc_dbase in this module which will need to be referenced. Update the command as follows:
:<tt>BC Database</tt><tt> ==</tt> ..\bc_dbase\bc_dbase_FMT_M02.csv
<li>We are using an updated GIS layer for the Flood Modeller Nodes. Update the command as follows:
 '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
<li>Lastly, update the following command to specify a new output folder for the results of this module:
:<tt>Output Folder</tt><tt> ==</tt> ..\results\FMT_M02\2d
<li>Save the file. The tcf file is now ready to be used.</ol>

==Flood Modeller Simulation Files==
<ol>
<li>Open the Flood Modeller Pro model as per [[Flood_Modeller_Tutorial_Module01 | Flood Modeller Tutorial Module 1]]
<li>Create a copy of '''FMT_M01_001.ief''' and save as '''FMT_M02_001.ief'''.
<li>In the 'Links' tab with the 2D scheme set as TUFLOW, change the full path of the 2D control file to the FMT_M02_DEV_001.tcf from the \FMT_Tutorial\FMT_M02\TUFLOW\runs folder
<li>Save the Scenario Data.</li></ol>

Use your preferred method to start the model FMT_M02_001.ief or follow the guidance in the [[Flood_Modeller_Tutorial_Module01 | Flood Modeller Tutorial Module 1]] page. If the simulation fails to start, please refer to the troubleshooting guidance on that page.

=Review Check Files=
Once the model has compiled and the simulation started, we can review the check files to ensure the changes have been correctly applied. The following section of this module outlines how the generated check files can be used to review each of the key changes we have made to the model. Note that there is often more than one check file that can be used to review each component of the model. The below steps outline just how some of these check files can be used.

=== Review Created TIN ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_DEM_Z.TIF

The FMT_M02_001_DEM_Z.TIF is a grid of the final zpts used by TUFLOW after processing of each of the layers within the TGC. It can be read by most mainstream GIS software and also visualised in SMS.

=== Review Changes to Roughness ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_grd_check

The grd_check file contains information on all cells within the model extent, such as ZC elevation and the location of the cell in relation to the model origin. One of the attributes of this check layer is the Material ID assigned to each cell. A review of this check file is recommended particularly when using multiple GIS layers to define the roughness of a 2D domain. The file can be colour coded to provide a visual representation of the roughness assigned to the entire model extent by:

*Changing the style of the grd_check file to 'Categorized' by the 'Material' column in QGIS
*By right clicking on the grd_check layer within the table of contents and click Properties. Once the properties dialogue window is open select the Symbology tab. Choose the Unique values option under Categories in the left-hand list and map the Value Field of interest.

=== Review Pipe Network ===
From the TUFLOW\check\1d\ folder open within QGIS:
*FMT_M02_001_nwk_C_check
*FMT_M02_001_nwk_N_check

These two check files provide information on all 1D elements within the model. The _nwk_C_check layer provides information on all 1D channels (including structures) in the model, whilst the _nwk_N_check layer provides information on the nodes. Notice how the _nwk_C check layer shows a series of dashed lines at the locations where we have specified pits in the model. These lines represent 'pit channels', zero length channels that connect the 1D pipe network to the 2D floodplain. Viewing in conjunction with the _nwk_N check layer shows two nodes are created at the upstream (ground level) and downstream (invert of the pipe network) ends of the pit channel.

=== Review Boundaries and 1D/2D Links ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_1d_to_2d_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. Where we have digitised the pipe network, this check file shows the SX boundaries that have been created at the location of the pits. This check file also shows the ZC elevation of the SX boundary which can be compared to surrounding ZC elevations by viewing alongside the grd_check layer. The check layer also shows the HX boundaries digitised along the river banks in Module 01.

=== Review Flood Modeller/ESTRY 1D/1D Links ===
The successful connection of the Flood Modeller and ESTRY networks can be checked by the presence of CHECK 1393 messages highlighting the presence of "X1DH" and "X1DQ" links to external nodes within the TUFLOW Log File. Alternatively, the success of the connectivity of the "X1DQ" and "X1DH" links can be assessed through reference to the _messages.SHP/GPKG GIS layer which contains CHECK 1393 at each ESTRY node linked to a Flood Modeller node.

=Review the Results=

Open the 2D results in the TUFLOW results viewer. It can be seen that during the flood event the capacity of the pipe network is exceeded resulting in flooding of the roads in the proposed development. 
[[File:M07 2d Results.PNG|800px]] 
 
The 1D ESTRY results can be viewed by opening the time series results using the approach described in the following page: [[TUFLOW Viewer - Load Results - Time Series]]. You can also open results from Flood Modeller within the TUFLOW Viewer using the instructions here: [[TUFLOW Viewer - Load Results - Time Series FM]]

It can be seen that there is negative flow in Pipe16 and Pipe18 when the water levels in the Flood Modeller node and the connected ESTRY nodes are such that backwater effects are present.
[[File:X1dh.png|alt=X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18|none|thumb|500x500px|X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18]]
A sense check of the flows being transferred across the "X1DQ" link can also be performed by plotting and comparing the flow time series for the first ESTRY node (ds3) and the last Flood Modeller node (ds2).
[[File:X1dq.png|alt=X1DQ Flow from Flood Modeller to Estry at DS3|none|thumb|500x500px|X1DQ Flow from Flood Modeller to Estry at DS3]]

We have now completed the tutorial and you should now be familiar with the approaches of linking Estry to Flood Modeller and vice versa.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model| Back to Tutorial Introduction Main Page]]
}}

Flood Modeller Tutorial Module02

2025-12-24T10:16:54Z

RussellGardner:

= Introduction =
In this module, a proposed development is represented within an existing model by adding TUFLOW 1D pipe network elements, which are then linked with Flood Modeller Pro.

This will include:
* Modification of the floodplain topography through the creation of a 3D TIN surface.
* Revision of the land use.
* Addition of pipes and pits in ESTRY to represent the underground network.
* Linking of the pipe network in ESTRY with the Flood Modeller network.
* Introduction of an inflow into the pipe system.
* Addition of a river reach represented in ESTRY downstream of the Flood Modeller network.

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module02_Archive |Tutorial Module 02]].

===Define Elevations (Building a TIN)===
The GIS layers necessary to modify the ground elevations to represent the proposed development are provided. This part of the tutorial demonstrates how a TIN is created from these GIS layers. The GIS defining the road crest level is also updated. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Elevations | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Elevations | QGIS - GPKG]]

===Define Surface Roughness===
The GIS layers necessary to modify the land use areas affected by the proposed development are provided. This part of the tutorial demonstrates how to populate the layer attributes to assign Manning’s n roughness values to each land use. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Roughness | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Roughness | QGIS - GPKG]]

===Define Pipe Network===
This part of the module creates the GIS layers that define the sub-surface pipe network. The inlets and pits of the pipe network are linked to the 2D domain. The pit inlet database is also created, linking the GIS layers to depth-discharge curves. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Pipe_Network | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Pipe_Network | QGIS - GPKG]]

===Define Boundary Conditions===
This part of the module demonstrates how an inflow can be applied directly to the pits of the pipe network. A GIS layer of the inflow boundary is provided. The existing Boundary Conditions Database is also modified to include these new inflows. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Boundary_Conditions | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Boundary_Conditions | QGIS - GPKG]]

==Flood Modeller 1D/ESTRY 1D Link==
This part of the module demonstrates how TUFLOW 1D (ESTRY) domains can be dynamically linked with Flood Modeller using "X1DH" and "X1DQ" links. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Flood Modeller1D/ESTRY 1D Link | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Flood Modeller1D/ESTRY 1D Link | QGIS - GPKG]]

The Flood Modeller 1D/ESTRY 1D link can be employed for a number of reasons, including:

* Inclusion of the pipe network and manhole modelling capabilities of ESTRY within a Flood Modeller – TUFLOW linked model (see [https://docs.tuflow.com/classic-hpc/manual/2025.1/DomainLinking-1.html#OneD2DLinkingFM-2 Section 10.5] of the TUFLOW Manual for more details).
* Extension of a Flood Modeller network within ESTRY to overcome Flood Modeller node licence limits.
* Representation of a steeper tributary in ESTRY which can then be connected to the main river represented in Flood Modeller.

Flood Modeller and TUFLOW (ESTRY) nodes are considered linked if an ESTRY node in a 1d_nwk layer and a Flood Modeller node in a [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNodes Read GIS X1D Nodes] or [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNetwork Read GIS X1D Network] layer are snapped together, or are within the snap tolerance distance specified.

ESTRY nodes are automatically generated at the upstream and downstream extremities of an ESTRY link, so manual generation of a node is not mandatory. If no node is manually added, the Flood Modeller–ESTRY link is assumed to be an “X1DH” link. If an ESTRY node is manually generated, the ESTRY node can have a 1d_nwk layer Conn_1D_2D attribute of either “X1DH” or “X1DQ”.

An "X1DH" link means a Flood Modeller 1D water level is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a water level and ESTRY sends back a +/- flow to Flood Modeller). An ESTRY "X1DH" link (the default) is typically used where ESTRY discharges into a Flood Modeller network. The "X1DH" link is applied to the Flood Modeller 1D network as a lateral inflow. The Flood Modeller 1D node connected to the ESTRY node by an "X1DH" connection must not be the end node of a reach.

An "X1DQ" link means a Flood Modeller inflow/outflow is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a +/- flow and ESTRY sends back a water level). This is more appropriate where a Flood Modeller network terminates and flows into an ESTRY model. The Flood Modeller 1D node at the end of an "X1DQ" connection must be an HTBDY unit, although it is not necessary for the HTBDY unit to contain any boundary data as this data is overridden by the water levels provided by TUFLOW.

=Modify Simulation Control Files=
With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.
== TUFLOW Geometry Control File (TGC) ==

At this stage, the following changes will be made to the geometry:

* A 3D TIN is created to represent changes to the ground elevations.
* Two 2d_mat layers are added to represent changes to the land use at the location of the proposed development.

<ol>
<li>Open FMT_M01_001.tgc in a text editor and save the file as FMT_M02_001.tgc.</li>

<li>Open FMT_M02_001.tgc.</li>

<li>Add the commands to modify the topography to represent the proposed development. These commands should be placed after the <tt>Read GIS Z Shape</tt> line:

 '''QGIS - SHP'''
 <tt>Create TIN Zpts WRITE TIN == gis\2d_ztin_fmt_m02_development_001_R.shp | gis\2d_ztin_fmt_m02_development_001_P.shp</tt>

 '''QGIS - GPKG'''
 <tt>Create TIN Zpts WRITE TIN == 2d_ztin_fmt_m02_development_001_R | 2d_ztin_fmt_m02_development_001_P</tt>

 The <tt>Create TIN Zpts WRITE TIN</tt> command creates and writes a .2dm mesh file to the same location as the GIS layer (in this case the TUFLOW\model\gis folder). The .2dm TIN can be viewed, checked, and modified in QGIS. It can then be read into the model directly using the <tt>Read TIN Zpts</tt> command for subsequent model simulations.

The 2d_mat layers created in this module build upon the existing commands that modify roughness. The new layers overwrite the existing layers at the location of the proposed development. This process of layering provides a powerful tool in TUFLOW that minimises data duplication and offers a means of quality control. The commands reading in the new 2d_mat layers must be placed after the existing commands.

 '''QGIS - SHP'''
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_001_R.shp</tt>
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_buildings_001_R.shp</tt>

 '''QGIS - GPKG'''
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_001_R</tt>
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_buildings_001_R</tt>
</li>
 
<li>Save the file. The TGC is now ready to be used.</li>
</ol>

== ESTRY Control File (ECF) ==
At this stage, the following changes are made to the ECF file:
* A 1d_nwk layer is created to represent the culverts of the proposed pipe network.
* A 1d_nwk layer is created to represent the pits of the proposed pipe network.
* A pit inlet database is created to link depth-discharge curves to the pit inlet type.

<ol>
<li>Open FMT_M01_001.ecf in your text editor. Save the file as FMT_M02_001.ecf.</li>
<li>Open FMT_M02_001.ecf </li>
<li>Add the following commands at the bottom of the file as follows:
<div>
'''QGIS - SHP''' 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pipes_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pits_001_P.shp 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Channels_001_L.shp 
<tt>Read GIS Table Links</tt> <tt>==</tt> xs\1d_xs_FMT_M02_Creek_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwke_X1DQ_P.shp 
<tt>Read GIS BC</tt> <tt>==</tt> gis\1d_BC_FMT_M02_001_P.shp 
'''QGIS - GPKG''' 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pipes_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pits_001_P 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Channels_001_L 
<tt>Read GIS Table Links</tt> <tt>==</tt> 1d_xs_FMT_M02_Creek_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwke_X1DQ_P 
<tt>Read GIS BC</tt> <tt>==</tt> 1d_BC_FMT_M02_001_P
</div>
</li>
<li value="4">Save the file. The ECF file is now ready to be used.</li>
</ol>

== TUFLOW Boundary Control File (TBC) ==
A 2d_sa layer will be created to define inflows into the pipe network and referenced in the TBC file.
<ol>
<li>Open FMT_M01_001.tbc in a text editor and save it as FMT_M02_001.tbc.</li>
<li>Insert the following commands after the existing <tt>Read GIS SA</tt><tt> ==</tt> mi\2d_sa_M01_002_R.shp command:</li>
'''QGIS - SHP''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> gis\2d_sa_FMT_M02_001_R.shp 
'''QGIS - GPKG''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> 2d_sa_FMT_M02_001_R 
<li>Save the file. The TBC file is now ready to be used.</li>
</ol>

==TUFLOW Control File (TCF)==

We will need to create a new tcf file that references the new tgc, ecf and tbc files.
<ol>
<li>Open FMT_M01_001.tcf and save as FMT_M02_DEV_001.tcf.
Update the following commands:
:<tt>Geometry Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tgc
:<tt>ESTRY Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.ecf
:<tt>BC Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tbc
<li>We have also created a new bc_dbase in this module which will need to be referenced. Update the command as follows:
:<tt>BC Database</tt><tt> ==</tt> ..\bc_dbase\bc_dbase_FMT_M02.csv
<li>We are using an updated GIS layer for the Flood Modeller Nodes. Update the command as follows:
 '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
<li>Lastly, update the following command to specify a new output folder for the results of this module:
:<tt>Output Folder</tt><tt> ==</tt> ..\results\FMT_M02\2d
<li>Save the file. The tcf file is now ready to be used.</ol>

==Flood Modeller Simulation Files==
<ol>
<li>Open the Flood Modeller Pro model as per [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial Module 1]]
<li>Create a copy of '''FMT_M01_001.ief''' and save as '''FMT_M02_001.ief'''.
<li>In the 'Links' tab with the 2D scheme set as TUFLOW, change the full path of the 2D control file to the FMT_M02_DEV_001.tcf from the \FMT_Tutorial\FMT_M02\TUFLOW\runs folder
<li>Save the Scenario Data.</li></ol>

Use your preferred method to start the model FMT_M02_001.ief or follow the guidance in the [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial Module 1]] page. If the simulation fails to start, please refer to the troubleshooting guidance on that page.

=Review Check Files=
Once the model has compiled and the simulation started, we can review the check files to ensure the changes have been correctly applied. The following section of this module outlines how the generated check files can be used to review each of the key changes we have made to the model. Note that there is often more than one check file that can be used to review each component of the model. The below steps outline just how some of these check files can be used.

=== Review Created TIN ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_DEM_Z.TIF

The FMT_M02_001_DEM_Z.TIF is a grid of the final zpts used by TUFLOW after processing of each of the layers within the TGC. It can be read by most mainstream GIS software and also visualised in SMS.

=== Review Changes to Roughness ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_grd_check

The grd_check file contains information on all cells within the model extent, such as ZC elevation and the location of the cell in relation to the model origin. One of the attributes of this check layer is the Material ID assigned to each cell. A review of this check file is recommended particularly when using multiple GIS layers to define the roughness of a 2D domain. The file can be colour coded to provide a visual representation of the roughness assigned to the entire model extent by:

*Changing the style of the grd_check file to 'Categorized' by the 'Material' column in QGIS
*By right clicking on the grd_check layer within the table of contents and click Properties. Once the properties dialogue window is open select the Symbology tab. Choose the Unique values option under Categories in the left-hand list and map the Value Field of interest.

=== Review Pipe Network ===
From the TUFLOW\check\1d\ folder open within QGIS:
*FMT_M02_001_nwk_C_check
*FMT_M02_001_nwk_N_check

These two check files provide information on all 1D elements within the model. The _nwk_C_check layer provides information on all 1D channels (including structures) in the model, whilst the _nwk_N_check layer provides information on the nodes. Notice how the _nwk_C check layer shows a series of dashed lines at the locations where we have specified pits in the model. These lines represent 'pit channels', zero length channels that connect the 1D pipe network to the 2D floodplain. Viewing in conjunction with the _nwk_N check layer shows two nodes are created at the upstream (ground level) and downstream (invert of the pipe network) ends of the pit channel.

=== Review Boundaries and 1D/2D Links ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_1d_to_2d_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. Where we have digitised the pipe network, this check file shows the SX boundaries that have been created at the location of the pits. This check file also shows the ZC elevation of the SX boundary which can be compared to surrounding ZC elevations by viewing alongside the grd_check layer. The check layer also shows the HX boundaries digitised along the river banks in Module 01.

=== Review Flood Modeller/ESTRY 1D/1D Links ===
The successful connection of the Flood Modeller and ESTRY networks can be checked by the presence of CHECK 1393 messages highlighting the presence of "X1DH" and "X1DQ" links to external nodes within the TUFLOW Log File. Alternatively, the success of the connectivity of the "X1DQ" and "X1DH" links can be assessed through reference to the _messages.SHP/GPKG GIS layer which contains CHECK 1393 at each ESTRY node linked to a Flood Modeller node.

=Review the Results=

Open the 2D results in the TUFLOW results viewer. It can be seen that during the flood event the capacity of the pipe network is exceeded resulting in flooding of the roads in the proposed development. 
[[File:M07 2d Results.PNG|800px]] 
 
The 1D ESTRY results can be viewed by opening the time series results using the approach described in the following page: [[TUFLOW Viewer - Load Results - Time Series]]. You can also open results from Flood Modeller within the TUFLOW Viewer using the instructions here: [[TUFLOW Viewer - Load Results - Time Series FM]]

It can be seen that there is negative flow in Pipe16 and Pipe18 when the water levels in the Flood Modeller node and the connected ESTRY nodes are such that backwater effects are present.
[[File:X1dh.png|alt=X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18|none|thumb|500x500px|X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18]]
A sense check of the flows being transferred across the "X1DQ" link can also be performed by plotting and comparing the flow time series for the first ESTRY node (ds3) and the last Flood Modeller node (ds2).
[[File:X1dq.png|alt=X1DQ Flow from Flood Modeller to Estry at DS3|none|thumb|500x500px|X1DQ Flow from Flood Modeller to Estry at DS3]]

We have now completed the tutorial and you should now be familiar with the approaches of linking Estry to Flood Modeller and vice versa.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model| Back to Tutorial Introduction Main Page]]
}}

Flood Modeller Tutorial Module01

2025-12-24T10:16:34Z

RussellGardner:

=Introduction=
In this module, an existing 2D TUFLOW domain is linked to a Flood Modeller 1D model.

The 2D domain represents the floodplain, while the 1D model represents the watercourse and in-channel structures. Linked 1D–2D models combine the strengths of both approaches. Here, the 1D scheme represents the largely unidirectional flow of the watercourse, while the 2D scheme captures the more complex floodplain hydraulics.

In the below 2D model example, the main channel is only 5-10 m wide, making the 5 m grid resolution too coarse to represent it accurately. This reduces the accuracy of conveyance within the channel. 
[[file:Poor_2d_rep.png|400px]] There are several options for improving the representation of this creek channel:
* Decrease the width of the 2D cells, either globally or by using Quadtree, and/or apply sub-grid sampling.
* Model the channel as a 1D network dynamically linked to the 2D domain (the floodplain).
For this module, the second option will be demonstrated.

TUFLOW can also link with other 1D solvers, including ESTRY (TUFLOW 1D), XP-SWMM and 12D Solutions’ Dynamic Drainage. Setting up a channel that cuts through a 2D domain is typically one of the more time-consuming modelling tasks.

For this module, the complete Flood Modeller 1D model network has been provided, to allow for progressing through the module in a relatively short period of time.

===Linking Flood Modeller to TUFLOW===

It is assumed from the outset of this module that Flood Modeller has already been linked to the desired version of TUFLOW. There are four methods by which Flood Modeller and TUFLOW can be linked, all of which are described on this [[Running_linked_Flood_Modeller_-_TUFLOW_Models | page]].

Using the Flood Modeller interface to set the location of the TUFLOW engine files for the TUFLOW build you want to use, is the simplest approach to linking Flood Modeller and TUFLOW and does not duplicate files. This method is recommended if it is expected that the same versions of Flood Modeller and TUFLOW will be used consistently when running linked models.

1) Open the Flood Modeller software and in the 'Home' tab select the 'General' option. 
[[file:FM Home Tab.png|500px]] 

2) Select the 'Project Settings' sub-menu and within the TUFLOW Engine File Location choose to browse to the version of TUFLOW that you would like to link Flood Modeller to. Choose 'Open' and then 'OK'. It is recommended that the option 'Show Solver Window when Running Simulations' be switched on as well. 

[[file:FM TUFLOW Linking 26092025.png|500px]] 

3) Save the changes that you have made to the setup. This will update the settings file (formed.ini).

4) Restart Flood Modeller to effect the revised setting.

4) The linked model can then be run by opening the .ief file within the Flood Modeller Interface and clicking Run. 

=Existing Model Data=
This tutorial builds upon the 2D TUFLOW domain that was constructed as part of [[Tutorial_M01 |Module 1]] and [[Tutorial_M02 |Module 2]] of the TUFLOW Tutorial Model.

The model developed in these tutorial modules already contains some culverts modelled as 1D elements. The culverts are modelled in ESTRY, TUFLOW's internal 1D engine. One of these culverts will be kept in ESTRY and the other will be added to the Flood Modeller model. The 2D boundary conditions (upstream inflows and downstream stage-discharge boundary) will be removed from the model. These will instead be represented in Flood Modeller as it is a more typical schematisation for a 1D/2D linked model.

The existing TUFLOW model consists of:
*Definition of Active/Inactive Areas
*Definition of Land Use areas for the spatial distribution of roughness values
*1D ESTRY culverts
*1D/2D boundary links to connect the 1D ESTRY culverts to the 2D TUFLOW domain.

= Project Initialisation =
TUFLOW models are separated into a series of folders which contain the input and output files. The recommended set up for the model directory and sub-folders is shown below. For a more detailed description, refer to the [https://docs.tuflow.com/classic-hpc/manual/2025.2/FoldersFileTypesandFileNaming-2.html#FoldersFileTypesandFileNaming-2]. 
<ol>
[[File:Tute M01 Directory Structure v3.png|left]]
{| class="wikitable"

! style="background-color:#005581; font-weight:bold; color:white;"| Sub-Folder
! style="background-color:#005581; font-weight:bold; color:white;" width=10%| Input / Output
! style="background-color:#005581; font-weight:bold; color:white;" width=75%| Description
|-
| bc_dbase|| Input || Boundary condition database(s) and input time-series data.
|-
| check|| Output || GIS and other check files to carry out quality control checks (use Write Check Files).
|-
| model|| Input ||Geometry (TGC), Boundary (TBC) and other model control text files (i.e. no GIS files).
|-
| model\gis|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\gis is typically used for all QGIS and ArcGIS files.
|-
| model\mi|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\mi is typically used for MapInfo formatted GIS files.
|-
| results|| Output|| TUFLOW outputs the results to this folder in specified formats.
|-
| runs|| Input|| TUFLOW Control Files (TCF).
|-
| runs\log|| Output || TUFLOW log files (TLF) and messages layers.
|}
</ol>
The TUFLOW folders can be set up manually, automatically running TUFLOW model with <tt> Write Empty GIS Files </tt> command or automatically through GIS programs:
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS | QGIS - SHP]]
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS_GPKG | QGIS - GPKG]]
:*SMS - the folder structure listed above is automatically created before running the model using the 'Export TUFLOW files' command (see [[Run TUFLOW from within SMS | Run TUFLOW from within SMS]]).
:*ArcMap (10.1 and newer) - the ArcTUFLOW Toolbox can be used to automatically create the model folders, model projection, TUFLOW control files and run TUFLOW to create the template files.

The following points on TUFLOW folders and filenames are worth noting:
:*TUFLOW accepts any folder structure, though the above listed format is most commonly used and is recommended. 
:*TUFLOW accepts spaces and special characters (such as ! or #) in filenames and paths, but other software may not. It is recommended that spaces and other special characters are not used in the simulation path and filenames. 
:*Folder paths, filenames, file extensions and TUFLOW commands are not case sensitive in any TUFLOW control files. 
:*Any directories that don't apply can be omitted, for example, if using QGIS or ArcMap the model\mi directory is not required. 
 

= Model Familiarisation=
Become familiar with the model location, using an aerial image and DEM: 
:*[[Model_Familiarisation_QGIS | QGIS]]
 

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module01_Archive |Tutorial Module 01]].

===Define the External 1D Networks===
This part of the module creates the GIS layers that specify the location of the Flood Modeller nodes that are to be connected to the 2D domain.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_x1D_Nodes | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_x1D_Nodes | QGIS - GPKG]]

===Define the Water Level Lines===
This part of the module creates the Water Level Lines that will be used to visualise 1D results in 2D map outputs.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_WLL_Lines | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_WLL_Lines | QGIS - GPKG]]

===Define the 1D/2D Boundary Links===
This part of the module creates the 1D/2D boundaries to link the Flood Modeller 1D component to the TUFLOW 2D domain.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Links | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Links | QGIS - GPKG]]

===Define Bank Elevations===
This part of the module defines the bank elevations of the watercourse which are the elevations of the 1D/2D boundary links created in the previous section.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_Banks | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_Banks | QGIS - GPKG]]

===Deactivate 2D cells ===
This part of the module describes the steps to deactivate the 2D cells where the 1D model is replacing the 2D solution.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Code | QGIS – SHP ]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Code | QGIS - GPKG]]

=Modify Simulation Control Files=

With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.

== TUFLOW Geometry Control File (TGC) ==
At this stage, the following changes will be made to the geometry:
* The cells along the watercourse that are represented in the 1D Flood Modeller component of the model are deactivated.
* Bank elevations along the watercourse are enforced.

<ol>
<li> In the '''FMT_Tutorial\FMT_M01\TUFLOW\model''' folder, save a copy of M01_5m_002.tgc as FMT_M01_001.tgc. </li>

<li> Open FMT_M01_001.tgc 
'''QGIS - SHP''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt>..\model\gis\2d_code_FMT_M01_001_R.shp 
<tt>Read GIS Code BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_R.shp <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R.shp''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R.shp''' deactivates selected cells along the watercourse.

 '''QGIS - GPKG''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt> 2d_code_FMT_M01_001_R 
<tt>Read GIS Code BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_R <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R''' deactivates selected cells along the watercourse. </li>

<li> Topography amendments should be added in a new section at the bottom of the TGC. These are: 
'''QGIS - SHP''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> gis\2d_bc_FMT_M01_HX_001_L.shp | gis\2d_bc_FMT_M01_HX_001_P.shp <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P.shp''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L.shp''' layer (defining bank location).

 '''QGIS - GPKG''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> 2d_bc_FMT_M01_HX_001_L | gis\2d_bc_FMT_M01_HX_001_P <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L''' layer (defining bank location). </li>

<li> Save the file. The geometry control file is now ready to be used. </li>
</ol>

==TUFLOW Boundary Control File (TBC)==
Next, update the TBC to reference the model boundary files created in the previous steps, as described below:

*Add the 1D/2D boundaries that link the Flood Modeller open channel to the 2D floodplain.
*Update the 1D/2D boundaries which link the ESTRY culverts to the 2D floodplain, as some of these culverts are now modelled in Flood Modeller.
*Remove the external inflows applied to the TUFLOW model, as these are now applied in Flood Modeller.

<ol>
<li> Open '''M02_5m_001.tbc''' and save a copy as '''FMT_M01_001.tbc'''.
<li> Remove the boundary linking to the TUFLOW inflows by putting an exclamation mark before the line reading: '''QGIS - SHP''' <tt>Read GIS BC</tt> <tt>== </tt> gis\2d_bc_M01_002_L.shp '''QGIS - GPKG''' <tt>Read GIS BC</tt> <tt>== </tt> 2d_bc_M01_002_L

<li> Add reference to the 1D/2D boundary links that connect Flood Modeller to the 2D floodplain:

 '''QGIS - SHP''' <tt>Read GIS BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_P.shp | gis\2d_bc_FMT_M01_HX_001_L.shp <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt> '''QGIS - GPKG''' <tt>Read GIS BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_P | 2d_bc_FMT_M01_HX_001_L <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt><li> Save the file. The boundary control file is now ready to be used.

</ol>

== TUFLOW Control File (TCF) ==
Finally, the TCF is updated as follows:
<ul>
<li>Remove references to model parameters that are read from Flood Modeller.
<li>Read in the GIS layer of the Flood Modeller nodes.
<li>Read in the GIS layers used to create Water Level Lines along the Flood Modeller component of the model (optional).
<li>Add a reference to the ESTRY Control File.
<li>Update references to the TBC and TGC.
</ul>The following steps outline how to apply these updates:

# In the \FMT_Tutorial\FMT_M01\TUFLOW\runs folder, save a copy of the TUFLOW file created as a part of [[Tutorial_M02 |Module 2]] ('''M02_5m_001.tcf''') as '''FMT_M01_001.tcf.'''
# Remove the Start Time, End Time, and 2D Timestep parameters from the TCF, as these are read from the Flood Modeller .ief file in a linked Flood Modeller-TUFLOW model. If they are left in place the Flood Modeller settings will override the TUFLOW settings. This is done by adding an exclamation mark in front of each of the following commands. <tt>! SIMULATION TIME CONTROL COMMANDS</tt> <tt>Timestep </tt> <tt>== </tt> 1.5 <tt>! Specifies a 2D computational timestep of 1.5 seconds </tt> <tt>Start time </tt> <tt>== </tt> 0 <tt>! Specifies a simulation start time of 0 hours</tt> <tt>End Time </tt> <tt>== </tt>3 <tt>! Specifies a simulation end time of 3 hours</tt>
#Read in the GIS layers of the Flood Modeller Nodes. Place the below command line anywhere in the .tcf. It is good practice to create a section within the .tcf to reference all 1D commands: '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
#Add commands to read in the GIS layers referencing Water Level Lines drawn along the Flood Modeller component of the model: '''QGIS - SHP''' <tt>Read GIS X1D Network</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nwk_001_L.shp <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> ..\model\gis\1d_x1d_WLL_FMT_M01_001_L.shp <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> '''QGIS - GPKG''' <tt>Read GIS X1D Network</tt> <tt>== </tt> 1d_x1d_FMT_M01_nwk_001_L <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> 1d_x1d_WLL_FMT_M01_001_L <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> The addition of TUFLOW Water Level Lines (WLL) allows the Flood Modeller 1D results to be visualised within the TUFLOW 2D map outputs. They provide a means by which to remove the gaps in the map outputs where the 1D Flood Modeller domains are located and the 2D cells are deactivated. To do this, TUFLOW requires a 1D_WLL layer to define the cross sections locations, and a 1d_nwk layer that defines the river centre line. The layers are not used in the hydraulic calculations and their inclusion is not always required. The Dist_for_Add_Points determines the intervals in metres at which interpolation points are inserted along each WLL.
#Add commands to read in an ESTRY Control File which contains references to some of the culverts present on the floodplain: <tt>ESTRY Control File</tt> <tt>== </tt>..\model\FMT_M01_001.ecf <tt>!Reference the ESTRY Control File </tt>
#Update the links to the Geometry control file, the Boundary Condition control file and the bc_dbase file: <tt>Geometry Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tgc <tt>BC Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tbc <tt>BC Database</tt> <tt>== </tt>..\bc_dbase\bc_dbase_FMT_M01.csv
</ol>
This concludes the changes needed to be made to the TCF.

=Flood Modeller Simulation Files=
A complete Flood Modeller model is provided in the '''FMT_M01\Flood_Modeller''' folder. The model files are located in the DAT, IED and IEF folders.

The DAT and IED files are complete and do not require modification to link with TUFLOW. The IEF file must be altered to create the link. These alterations can be made in a text editor or in the Flood Modeller interface.

The instructions below are written for Flood Modeller interface version 7.2.

===IEF File===
<ul>
<li> Open Flood Modeller. Select 'Load 1D Network'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\DAT''' and load the '''FMT_M01_001.dat'''.</li>
<li> Right click 'Event Data' and select 'Add Item'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' and load the '''FMT_Inflows.IED'''.</li>

<li> On the 'Simulation' tab, click New 1D Simulation. Save the file when prompted in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IEF''' folder as '''FMT_M01_001.ief'''</li>
<li> On the 'Files' Tab of the simulation window, set the following parameters:</li>
*Event Title: FMT_M01_001
*1D Data File: The full path to the \FMT_Tutorial\FMT_M01\Flood_Modeller\DAT\FMT_M01_001.dat
*Use Initial Conditions from: Network File (.dat)
*Results File: set the full path to \FMT_Tutorial\FMT_M01\Flood_Modeller\RES\FMT_M01_001.
[[File:Ief file.png|frameless|500x500px]]
<li>To the right of the Event Data box, click Add and select the '''FMT_Inflows.IED''' file in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' folder.</li>

<li>On the 'Times' tab, replace the simulation time parameters that were removed from TUFLOW. Enter the following parameters:</li>
*Run Type: Unsteady (Fixed Timestep)
*Start Time (hrs): 0
*Finish Time (hrs): 3
*Timestep (s):1
*Save Interval (s): 300.
[[File:Ief time.png|frameless|500x500px]]

<li> Add the 'Links' tab by clicking View> Tabs > Links. On the 'Links' tab, enter the following parameters:
*2-d Scheme: TUFLOW
*2-d Timestep: 2
*Check the box for ‘Perform corrective 1D timestep’
*2-d control file: full path to the '''FMT_M01_001.tcf''' from the '''\FMT_Tutorial\FMT_M01\TUFLOW\runs''' folder.
[[File:Ief tcf.png|frameless|500x500px]]
</li></li><li></li><li> Save the Scenario Data and run the Flood Modeller simulation. </li>{{Video|name=Setting up FMP IEF Simulation File.mp4 |width=1123}}</ul>

= Review Check Files =

=== Review Boundaries and 1D/2D Links ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M02_001_1d_to_2d_check
*FMT_M02_001_sac_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. In this case it should show the HX boundaries that have been digitised along the river banks.

The _sac_check layer highlights the lowest 2d cells within the SA boundary polygon to which inflow is first distributed.

=== Review Bank Elevations ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M01_001_zln_zpt_check_P

The _zln_zpt_check layer highlights the cells whose elevations have been modified by z lines to represent the bank crests of the watercourse.

= Review the Results =
Instructions for viewing the TUFLOW mesh (XMDF) and 1D time series (.tpc) outputs are provided in [[Tutorial_M01_Results_QGIS | Module 1]] and [[Tutorial_M03_Results_QGIS | Module 3.]] It is often useful to view 1D Flood Modeller results alongside 2D TUFLOW map outputs. The Flood Modeller results can be opened in QGIS with the TUFLOW Viewer plugin, together with the TUFLOW mesh results, by following the linked instructions. Alternatively, the TUFLOW mesh results can be loaded directly into the Flood Modeller Pro interface.

The video below demonstrates both methods:
*[[TUFLOW Viewer - Load Results - Time Series FM|Loading Flood Modeller 1D results]] in QGIS using the TUFLOW Viewer plugin.
*Loading TUFLOW mesh results in Flood Modeller Pro.
{{Video|name=Viewing Results in Flood Modeller and TUFLOW.mp4.mp4 |width=1123}}

= Troubleshooting =

=== Troubleshooting for HPC Simulation ===

If the following error message is encountered when running the TUFLOW HPC model:

<pre>ERROR 3999 - ptx file version mismatch
</pre>

Please ensure that the four TUFLOW kernel files below have been transferred from your TUFLOW engine folder into your Flood Modeller "bin" folder.

*hpcKernels_nSP.ptx
*hpcKernels_nDP.ptx
*qpcKernels_nSP.ptx
*qpcKernels_nDP.ptx

=== Troubleshooting for GPU Simulation ===
If the following error is encountered when running the TUFLOW HPC model using GPU hardware: :
<pre>TUFLOW GPU: Interrogating CUDA enabled GPUs …
TUFLOW GPU: Error: Non-CUDA Success Code returned
</pre>
or
<pre>ERROR 2785 - No GPU devices found, enabled or compatible.
</pre>
Please try the following steps:
<ol>
<li> Check if the GPU card is an NVIDIA GPU card. Currently, TUFLOW does not run on AMD type GPU.
<li> Check if the NVIDIA GPU card is CUDA enabled and whether the latest drivers are installed (see [[GPU_Setup |GPU Setup)]].
</ol>If an issue not described above is encountered, an email should be sent to [mailto:support@tuflow.com support@tuflow.com]. 

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model| Back to Tutorial Introduction Main Page]]
}}

Flood Modeller Tutorial Model

2025-12-24T10:16:01Z

RussellGardner: /* Modules */

=Introduction=
The objective of the Flood Modeller - TUFLOW modules is to demonstrate how TUFLOW links to the external Flood Modeller 1D scheme and the methods available to create this link. They are designed to supplement existing documentation and assume prior knowledge of both Flood Modeller and TUFLOW software packages.

These modules were developed by BMT in collaboration with Jacobs. Comments, requests and feedback can be sent to [mailto:support@tuflow.com support@tuflow.com].

=Requirements and Downloads=
Both TUFLOW and Flood Modeller have modest system requirements for small models such as those used in these modules. Larger and more complex models, however, may require higher hardware specifications, particularly memory (RAM). The tutorial models are intentionally small to ensure quick simulation and load times, and should run on any modern PC or laptop capable of running Windows 7 or later.

TUFLOW models typically require access to a GIS package, a text editor, Microsoft Excel and a results viewer to build, review and visualise a model. A list of compatible packages is available on the TUFLOW Wiki. Flood Modeller can also be used as a graphical user interface for creating and editing GIS layers in a TUFLOW model, as well as for visualising results.

Instructions for Flood Modeller - TUFLOW modules are provided using the following GIS file formats:

* '''QGIS - SHP'''

* '''QGIS - GPKG'''

{| class="wikitable" width="75%"

! style="background-color:#005581; font-weight:bold; color:white;"| Requirement
! style="background-color:#005581; font-weight:bold; color:white;" | Brief Description
! style="background-color:#005581; font-weight:bold; color:white;" | Download
|-

| '''TUFLOW''' || TUFLOW is a computer program for simulating depth-averaged, one dimensional free-surface flows such as occurs from floods and tides, with the 2D solution occurring over a regular grid of square elements. 

It is commonly used in the UK and Ireland, Australia and the United States for the modelling of surface waters, river systems and pipe networks. 

It is recommended to always use the latest release version of TUFLOW. 

This tutorial model does not require a TUFLOW licence. 

This tutorial is set up to use a NVIDIA GPU card. If this is not available, CPU can be specfied within the [https://docs.tuflow.com/classic-hpc/manual/2025.2/TCFCommands-1.html#tcfHardware Hardware] command. 
||The TUFLOW executable is provided within the [https://wiki.tuflow.com/Tutorial_Introduction#Module_Data Tutorial Dataset].
|-

|'''Flood Modeller'''|| Flood Modeller (previously known as ISIS) is a commercial flood modelling package developed by Jacobs for simulating depth-averaged one and two dimensional free surface flows. It is primarily used for the simulation of river channels and is widely used within the UK and Ireland. This tutorial model will only leverage Flood Modeller’s 1D Solver. 
TUFLOW 1D and 2D domains can be dynamically linked to the 1D domain of Flood Modeller. Flood Modeller is not included within the TUFLOW executable and must be downloaded separately. 

Unlike TUFLOW Flood Modeller has a standalone Graphical User Interface which can be used to build networks, run models, and visualise results.

It is recommended that TUFLOW 2020-10-AD or later is used in conjunction with Flood Modeller Version 5 or later. [https://docs.tuflow.com/classic-hpc/manual/2025.2/OneD2DLinkingFM-2.html#fig:fig-FMTUFLOWVersionCompatability Figure 10.15] of the [https://docs.tuflow.com/classic-hpc/manual/2025.2/ 2025 TUFLOW manual] provides a list of compatibility between recent Flood Modeller and TUFLOW versions. 

For Flood Modeller Version 5 or later a Standard, Professional, or Unlimited Edition of Flood Modeller Pro is required to open and run the tutorial model.
||[https://www.floodmodeller.com/downloads/ Latest 64-bit version of Flood Modeller]. 
|-
| '''QGIS''' QGIS TUFLOW plugin || A Geographic Information System (GIS) used to build models and view results. This tutorial was developed with QGIS 3.20. It is recommended to have QGIS 3.20 or later to ensure compatibility with TUFLOW plugin latest features. 

The TUFLOW plugin includes numerous tools to increase workflow efficiency. 

||[https://qgis.org/download/ Latest 64-bit version of QGIS]. 

[[TUFLOW_QGIS_Plugin| QGIS TUFLOW Plugin Installation]].
|-
| '''NotePad++''' Syntax Highlighting || A text editor is required for creation of the TUFLOW input files. This tutorial was developed with NotePad++. Ideally a text editor should be able to: 
*Colour code the TUFLOW control files;
*Open other files from the active control file; and
*Launch a TUFLOW simulation. 
TUFLOW colour coding can be enabled using syntax highlighting.
|| [https://notepad-plus-plus.org/downloads/ Latest 64-bit version of Notepad++]. 

[https://downloads.tuflow.com/_archive/Miscellaneous/NPP_TUFLOW_Syntax_Highlighting.zip TUFLOW syntax highlighting for Notepad++]. For instructions on configuring Notepad++ for TUFLOW modelling, see [[NotepadPlusPlus_Tips |Notepad++ tips]].
|-
| '''Microsoft Excel''' || A spreadsheet software is required for working with tabular data and .csv files. This tutorial has been created in Excel. ||
|}
=Module Data=
To build the tutorial model, download one of the datasets below. This includes a digital elevation model (DEM), aerial photography, background model data for the tutorial model and a working version of the model. There are two formats available, Shapefile and GeoPackage. The GeoPackage format has been supported since the 2023-03 Release, for tips on its use see [https://wiki.tuflow.com/GeoPackage_Tips GeoPackage Tips].
*[https://downloads.tuflow.com/_archive/TUFLOW/Tutorial_Model/QGIS_SHP_FMP_Tut_Model.zip QGIS SHP Download]
*[https://downloads.tuflow.com/_archive/TUFLOW/Tutorial_Model/QGIS_GPKG_FMP_Tut_Model.zip QGIS GPKG Download]
If would you like to download the tutorial model datasets for ArcGIS or MapInfo, these can be found on the [[Flood_Modeller_Tutorial_Model_Archive | Archive Page]].

=Recommended Reading=
The aim of this tutorial is to demonstrate the steps undertaken to build, review and visualise the results of a linked Flood Modeller – TUFLOW model. It assumes that the user has a good understanding of both the 1D component of Flood Modeller and the 1D and 2D components of TUFLOW. The following resources may be of use:
*[[Tutorial_Introduction |TUFLOW Tutorial Model]]
*[https://docs.tuflow.com/classic-hpc/manual/2025.2/ TUFLOW Classic / HPC User Manual]
*[https://help.floodmodeller.com/docs/getting-started-with-1d-river-modelling Flood Modeller 1D Quick Start Guide]
*[https://help.floodmodeller.com/docs/technical-reference Flood Modeller Technical Reference]

=Modules=
The tutorial is presented over a series of modules, with each module offering the opportunity to run the model and review the results. Each of the modules builds upon the previous iteration with models developed in the previous module made available.

New users are advised to undertake the modules in sequence, whilst more experienced users can skip to modules containing specific features of interest. Results and check files are not included to keep the size of the download file manageable, but can be generated through the running of the simulations. The folder should be placed in a location with write permissions. The first tutorial module introduces the user to the linking of a TUFLOW 2D domain to a 1D Flood Modeller model. From this tutorial you will learn how to link an existing Flood Modeller 1D model to a TUFLOW 2D domain. This tutorial is ideal for those starting to learn how to link Flood Modeller and TUFLOW.

:*[[ Flood_Modeller_Tutorial_Module01 | Flood Modeller Module 1]] - Linking Flood Modeller to TUFLOW

The second tutorial demonstrates the linking of an ESTRY pipe network to an existing Flood Modeller – TUFLOW linked model. From this tutorial you will learn how to add a 1D pipe network and connect it to the representation of the watercourse created in Flood Modeller and link it to the TUFLOW representation of the floodplain created as part of the first tutorial. The second tutorial is ideal for those who would like to learn more about the interaction of TUFLOW with Flood Modeller including the simulation of fully integrated drainage systems.
:*[[ Flood_Modeller_Tutorial_Module02 | Flood Modeller Module 2]] - Linking Flood Modeller to ESTRY

 
{{Tips Navigation
|uplink=[[Main_Page| Back to Main Page]]
}}

Flood Modeller Tutorial Model

2025-12-24T10:15:38Z

RussellGardner:

=Introduction=
The objective of the Flood Modeller - TUFLOW modules is to demonstrate how TUFLOW links to the external Flood Modeller 1D scheme and the methods available to create this link. They are designed to supplement existing documentation and assume prior knowledge of both Flood Modeller and TUFLOW software packages.

These modules were developed by BMT in collaboration with Jacobs. Comments, requests and feedback can be sent to [mailto:support@tuflow.com support@tuflow.com].

=Requirements and Downloads=
Both TUFLOW and Flood Modeller have modest system requirements for small models such as those used in these modules. Larger and more complex models, however, may require higher hardware specifications, particularly memory (RAM). The tutorial models are intentionally small to ensure quick simulation and load times, and should run on any modern PC or laptop capable of running Windows 7 or later.

TUFLOW models typically require access to a GIS package, a text editor, Microsoft Excel and a results viewer to build, review and visualise a model. A list of compatible packages is available on the TUFLOW Wiki. Flood Modeller can also be used as a graphical user interface for creating and editing GIS layers in a TUFLOW model, as well as for visualising results.

Instructions for Flood Modeller - TUFLOW modules are provided using the following GIS file formats:

* '''QGIS - SHP'''

* '''QGIS - GPKG'''

{| class="wikitable" width="75%"

! style="background-color:#005581; font-weight:bold; color:white;"| Requirement
! style="background-color:#005581; font-weight:bold; color:white;" | Brief Description
! style="background-color:#005581; font-weight:bold; color:white;" | Download
|-

| '''TUFLOW''' || TUFLOW is a computer program for simulating depth-averaged, one dimensional free-surface flows such as occurs from floods and tides, with the 2D solution occurring over a regular grid of square elements. 

It is commonly used in the UK and Ireland, Australia and the United States for the modelling of surface waters, river systems and pipe networks. 

It is recommended to always use the latest release version of TUFLOW. 

This tutorial model does not require a TUFLOW licence. 

This tutorial is set up to use a NVIDIA GPU card. If this is not available, CPU can be specfied within the [https://docs.tuflow.com/classic-hpc/manual/2025.2/TCFCommands-1.html#tcfHardware Hardware] command. 
||The TUFLOW executable is provided within the [https://wiki.tuflow.com/Tutorial_Introduction#Module_Data Tutorial Dataset].
|-

|'''Flood Modeller'''|| Flood Modeller (previously known as ISIS) is a commercial flood modelling package developed by Jacobs for simulating depth-averaged one and two dimensional free surface flows. It is primarily used for the simulation of river channels and is widely used within the UK and Ireland. This tutorial model will only leverage Flood Modeller’s 1D Solver. 
TUFLOW 1D and 2D domains can be dynamically linked to the 1D domain of Flood Modeller. Flood Modeller is not included within the TUFLOW executable and must be downloaded separately. 

Unlike TUFLOW Flood Modeller has a standalone Graphical User Interface which can be used to build networks, run models, and visualise results.

It is recommended that TUFLOW 2020-10-AD or later is used in conjunction with Flood Modeller Version 5 or later. [https://docs.tuflow.com/classic-hpc/manual/2025.2/OneD2DLinkingFM-2.html#fig:fig-FMTUFLOWVersionCompatability Figure 10.15] of the [https://docs.tuflow.com/classic-hpc/manual/2025.2/ 2025 TUFLOW manual] provides a list of compatibility between recent Flood Modeller and TUFLOW versions. 

For Flood Modeller Version 5 or later a Standard, Professional, or Unlimited Edition of Flood Modeller Pro is required to open and run the tutorial model.
||[https://www.floodmodeller.com/downloads/ Latest 64-bit version of Flood Modeller]. 
|-
| '''QGIS''' QGIS TUFLOW plugin || A Geographic Information System (GIS) used to build models and view results. This tutorial was developed with QGIS 3.20. It is recommended to have QGIS 3.20 or later to ensure compatibility with TUFLOW plugin latest features. 

The TUFLOW plugin includes numerous tools to increase workflow efficiency. 

||[https://qgis.org/download/ Latest 64-bit version of QGIS]. 

[[TUFLOW_QGIS_Plugin| QGIS TUFLOW Plugin Installation]].
|-
| '''NotePad++''' Syntax Highlighting || A text editor is required for creation of the TUFLOW input files. This tutorial was developed with NotePad++. Ideally a text editor should be able to: 
*Colour code the TUFLOW control files;
*Open other files from the active control file; and
*Launch a TUFLOW simulation. 
TUFLOW colour coding can be enabled using syntax highlighting.
|| [https://notepad-plus-plus.org/downloads/ Latest 64-bit version of Notepad++]. 

[https://downloads.tuflow.com/_archive/Miscellaneous/NPP_TUFLOW_Syntax_Highlighting.zip TUFLOW syntax highlighting for Notepad++]. For instructions on configuring Notepad++ for TUFLOW modelling, see [[NotepadPlusPlus_Tips |Notepad++ tips]].
|-
| '''Microsoft Excel''' || A spreadsheet software is required for working with tabular data and .csv files. This tutorial has been created in Excel. ||
|}
=Module Data=
To build the tutorial model, download one of the datasets below. This includes a digital elevation model (DEM), aerial photography, background model data for the tutorial model and a working version of the model. There are two formats available, Shapefile and GeoPackage. The GeoPackage format has been supported since the 2023-03 Release, for tips on its use see [https://wiki.tuflow.com/GeoPackage_Tips GeoPackage Tips].
*[https://downloads.tuflow.com/_archive/TUFLOW/Tutorial_Model/QGIS_SHP_FMP_Tut_Model.zip QGIS SHP Download]
*[https://downloads.tuflow.com/_archive/TUFLOW/Tutorial_Model/QGIS_GPKG_FMP_Tut_Model.zip QGIS GPKG Download]
If would you like to download the tutorial model datasets for ArcGIS or MapInfo, these can be found on the [[Flood_Modeller_Tutorial_Model_Archive | Archive Page]].

=Recommended Reading=
The aim of this tutorial is to demonstrate the steps undertaken to build, review and visualise the results of a linked Flood Modeller – TUFLOW model. It assumes that the user has a good understanding of both the 1D component of Flood Modeller and the 1D and 2D components of TUFLOW. The following resources may be of use:
*[[Tutorial_Introduction |TUFLOW Tutorial Model]]
*[https://docs.tuflow.com/classic-hpc/manual/2025.2/ TUFLOW Classic / HPC User Manual]
*[https://help.floodmodeller.com/docs/getting-started-with-1d-river-modelling Flood Modeller 1D Quick Start Guide]
*[https://help.floodmodeller.com/docs/technical-reference Flood Modeller Technical Reference]

=Modules=
The tutorial is presented over a series of modules, with each module offering the opportunity to run the model and review the results. Each of the modules builds upon the previous iteration with models developed in the previous module made available.

New users are advised to undertake the modules in sequence, whilst more experienced users can skip to modules containing specific features of interest. Results and check files are not included to keep the size of the download file manageable, but can be generated through the running of the simulations. The folder should be placed in a location with write permissions. The first tutorial module introduces the user to the linking of a TUFLOW 2D domain to a 1D Flood Modeller model. From this tutorial you will learn how to link an existing Flood Modeller 1D model to a TUFLOW 2D domain. This tutorial is ideal for those starting to learn how to link Flood Modeller and TUFLOW.

:*[[ Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Module 1]] - Linking Flood Modeller to TUFLOW

The second tutorial demonstrates the linking of an ESTRY pipe network to an existing Flood Modeller – TUFLOW linked model. From this tutorial you will learn how to add a 1D pipe network and connect it to the representation of the watercourse created in Flood Modeller and link it to the TUFLOW representation of the floodplain created as part of the first tutorial. The second tutorial is ideal for those who would like to learn more about the interaction of TUFLOW with Flood Modeller including the simulation of fully integrated drainage systems.
:*[[ Flood_Modeller_Tutorial_Module02_Provisional | Flood Modeller Module 2]] - Linking Flood Modeller to ESTRY

 
{{Tips Navigation
|uplink=[[Main_Page| Back to Main Page]]
}}

Flood Modeller Tutorial Module02

2025-12-24T10:15:14Z

RussellGardner:

= Introduction =
In this module, a proposed development is represented within an existing model by adding TUFLOW 1D pipe network elements, which are then linked with Flood Modeller Pro.

This will include:
* Modification of the floodplain topography through the creation of a 3D TIN surface.
* Revision of the land use.
* Addition of pipes and pits in ESTRY to represent the underground network.
* Linking of the pipe network in ESTRY with the Flood Modeller network.
* Introduction of an inflow into the pipe system.
* Addition of a river reach represented in ESTRY downstream of the Flood Modeller network.

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module02_Archive |Tutorial Module 02]].

===Define Elevations (Building a TIN)===
The GIS layers necessary to modify the ground elevations to represent the proposed development are provided. This part of the tutorial demonstrates how a TIN is created from these GIS layers. The GIS defining the road crest level is also updated. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Elevations | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Elevations | QGIS - GPKG]]

===Define Surface Roughness===
The GIS layers necessary to modify the land use areas affected by the proposed development are provided. This part of the tutorial demonstrates how to populate the layer attributes to assign Manning’s n roughness values to each land use. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Define_Roughness | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Define_Roughness | QGIS - GPKG]]

===Define Pipe Network===
This part of the module creates the GIS layers that define the sub-surface pipe network. The inlets and pits of the pipe network are linked to the 2D domain. The pit inlet database is also created, linking the GIS layers to depth-discharge curves. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Pipe_Network | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Pipe_Network | QGIS - GPKG]]

===Define Boundary Conditions===
This part of the module demonstrates how an inflow can be applied directly to the pits of the pipe network. A GIS layer of the inflow boundary is provided. The existing Boundary Conditions Database is also modified to include these new inflows. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Boundary_Conditions | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Boundary_Conditions | QGIS - GPKG]]

==Flood Modeller 1D/ESTRY 1D Link==
This part of the module demonstrates how TUFLOW 1D (ESTRY) domains can be dynamically linked with Flood Modeller using "X1DH" and "X1DQ" links. Instructions are available below for the preferred GIS format:

* [[FM Tutorial M02_QGIS_SHP_Flood Modeller1D/ESTRY 1D Link | QGIS - SHP]]
* [[FM Tutorial M02_QGIS_GPKG_Flood Modeller1D/ESTRY 1D Link | QGIS - GPKG]]

The Flood Modeller 1D/ESTRY 1D link can be employed for a number of reasons, including:

* Inclusion of the pipe network and manhole modelling capabilities of ESTRY within a Flood Modeller – TUFLOW linked model (see [https://docs.tuflow.com/classic-hpc/manual/2025.1/DomainLinking-1.html#OneD2DLinkingFM-2 Section 10.5] of the TUFLOW Manual for more details).
* Extension of a Flood Modeller network within ESTRY to overcome Flood Modeller node licence limits.
* Representation of a steeper tributary in ESTRY which can then be connected to the main river represented in Flood Modeller.

Flood Modeller and TUFLOW (ESTRY) nodes are considered linked if an ESTRY node in a 1d_nwk layer and a Flood Modeller node in a [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNodes Read GIS X1D Nodes] or [https://docs.tuflow.com/classic-hpc/manual/2025.1/TCFCommands-1.html#tcfReadGISX1DNetwork Read GIS X1D Network] layer are snapped together, or are within the snap tolerance distance specified.

ESTRY nodes are automatically generated at the upstream and downstream extremities of an ESTRY link, so manual generation of a node is not mandatory. If no node is manually added, the Flood Modeller–ESTRY link is assumed to be an “X1DH” link. If an ESTRY node is manually generated, the ESTRY node can have a 1d_nwk layer Conn_1D_2D attribute of either “X1DH” or “X1DQ”.

An "X1DH" link means a Flood Modeller 1D water level is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a water level and ESTRY sends back a +/- flow to Flood Modeller). An ESTRY "X1DH" link (the default) is typically used where ESTRY discharges into a Flood Modeller network. The "X1DH" link is applied to the Flood Modeller 1D network as a lateral inflow. The Flood Modeller 1D node connected to the ESTRY node by an "X1DH" connection must not be the end node of a reach.

An "X1DQ" link means a Flood Modeller inflow/outflow is applied at the ESTRY node (i.e. Flood Modeller sends ESTRY a +/- flow and ESTRY sends back a water level). This is more appropriate where a Flood Modeller network terminates and flows into an ESTRY model. The Flood Modeller 1D node at the end of an "X1DQ" connection must be an HTBDY unit, although it is not necessary for the HTBDY unit to contain any boundary data as this data is overridden by the water levels provided by TUFLOW.

=Modify Simulation Control Files=
With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.
== TUFLOW Geometry Control File (TGC) ==

At this stage, the following changes will be made to the geometry:

* A 3D TIN is created to represent changes to the ground elevations.
* Two 2d_mat layers are added to represent changes to the land use at the location of the proposed development.

<ol>
<li>Open FMT_M01_001.tgc in a text editor and save the file as FMT_M02_001.tgc.</li>

<li>Open FMT_M02_001.tgc.</li>

<li>Add the commands to modify the topography to represent the proposed development. These commands should be placed after the <tt>Read GIS Z Shape</tt> line:

 '''QGIS - SHP'''
 <tt>Create TIN Zpts WRITE TIN == gis\2d_ztin_fmt_m02_development_001_R.shp | gis\2d_ztin_fmt_m02_development_001_P.shp</tt>

 '''QGIS - GPKG'''
 <tt>Create TIN Zpts WRITE TIN == 2d_ztin_fmt_m02_development_001_R | 2d_ztin_fmt_m02_development_001_P</tt>

 The <tt>Create TIN Zpts WRITE TIN</tt> command creates and writes a .2dm mesh file to the same location as the GIS layer (in this case the TUFLOW\model\gis folder). The .2dm TIN can be viewed, checked, and modified in QGIS. It can then be read into the model directly using the <tt>Read TIN Zpts</tt> command for subsequent model simulations.

The 2d_mat layers created in this module build upon the existing commands that modify roughness. The new layers overwrite the existing layers at the location of the proposed development. This process of layering provides a powerful tool in TUFLOW that minimises data duplication and offers a means of quality control. The commands reading in the new 2d_mat layers must be placed after the existing commands.

 '''QGIS - SHP'''
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_001_R.shp</tt>
 <tt>Read GIS Mat == gis\2d_mat_fmt_m02_dev_buildings_001_R.shp</tt>

 '''QGIS - GPKG'''
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_001_R</tt>
 <tt>Read GIS Mat == 2d_mat_fmt_m02_dev_buildings_001_R</tt>
</li>
 
<li>Save the file. The TGC is now ready to be used.</li>
</ol>

== ESTRY Control File (ECF) ==
At this stage, the following changes are made to the ECF file:
* A 1d_nwk layer is created to represent the culverts of the proposed pipe network.
* A 1d_nwk layer is created to represent the pits of the proposed pipe network.
* A pit inlet database is created to link depth-discharge curves to the pit inlet type.

<ol>
<li>Open FMT_M01_001.ecf in your text editor. Save the file as FMT_M02_001.ecf.</li>
<li>Open FMT_M02_001.ecf </li>
<li>Add the following commands at the bottom of the file as follows:
<div>
'''QGIS - SHP''' 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pipes_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Pits_001_P.shp 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwk_FMT_M02_Channels_001_L.shp 
<tt>Read GIS Table Links</tt> <tt>==</tt> xs\1d_xs_FMT_M02_Creek_001_L.shp 
<tt>Read GIS Network</tt> <tt>==</tt> gis\1d_nwke_X1DQ_P.shp 
<tt>Read GIS BC</tt> <tt>==</tt> gis\1d_BC_FMT_M02_001_P.shp 
'''QGIS - GPKG''' 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pipes_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Pits_001_P 
<tt>Pit Inlet Database</tt> <tt>==</tt> ..\pit_dbase\pit_inlet_dbase.csv 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwk_FMT_M02_Channels_001_L 
<tt>Read GIS Table Links</tt> <tt>==</tt> 1d_xs_FMT_M02_Creek_001_L 
<tt>Read GIS Network</tt> <tt>==</tt> 1d_nwke_X1DQ_P 
<tt>Read GIS BC</tt> <tt>==</tt> 1d_BC_FMT_M02_001_P
</div>
</li>
<li value="4">Save the file. The ECF file is now ready to be used.</li>
</ol>

== TUFLOW Boundary Control File (TBC) ==
A 2d_sa layer will be created to define inflows into the pipe network and referenced in the TBC file.
<ol>
<li>Open FMT_M01_001.tbc in a text editor and save it as FMT_M02_001.tbc.</li>
<li>Insert the following commands after the existing <tt>Read GIS SA</tt><tt> ==</tt> mi\2d_sa_M01_002_R.shp command:</li>
'''QGIS - SHP''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> gis\2d_sa_FMT_M02_001_R.shp 
'''QGIS - GPKG''' 
<tt>Read GIS SA PITS</tt><tt> ==</tt> 2d_sa_FMT_M02_001_R 
<li>Save the file. The TBC file is now ready to be used.</li>
</ol>

==TUFLOW Control File (TCF)==

We will need to create a new tcf file that references the new tgc, ecf and tbc files.
<ol>
<li>Open FMT_M01_001.tcf and save as FMT_M02_DEV_001.tcf.
Update the following commands:
:<tt>Geometry Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tgc
:<tt>ESTRY Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.ecf
:<tt>BC Control File</tt><tt> ==</tt> ..\model\FMT_M02_001.tbc
<li>We have also created a new bc_dbase in this module which will need to be referenced. Update the command as follows:
:<tt>BC Database</tt><tt> ==</tt> ..\bc_dbase\bc_dbase_FMT_M02.csv
<li>We are using an updated GIS layer for the Flood Modeller Nodes. Update the command as follows:
 '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
<li>Lastly, update the following command to specify a new output folder for the results of this module:
:<tt>Output Folder</tt><tt> ==</tt> ..\results\FMT_M02\2d
<li>Save the file. The tcf file is now ready to be used.</ol>

==Flood Modeller Simulation Files==
<ol>
<li>Open the Flood Modeller Pro model as per [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial Module 1]]
<li>Create a copy of '''FMT_M01_001.ief''' and save as '''FMT_M02_001.ief'''.
<li>In the 'Links' tab with the 2D scheme set as TUFLOW, change the full path of the 2D control file to the FMT_M02_DEV_001.tcf from the \FMT_Tutorial\FMT_M02\TUFLOW\runs folder
<li>Save the Scenario Data.</li></ol>

Use your preferred method to start the model FMT_M02_001.ief or follow the guidance in the [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial Module 1]] page. If the simulation fails to start, please refer to the troubleshooting guidance on that page.

=Review Check Files=
Once the model has compiled and the simulation started, we can review the check files to ensure the changes have been correctly applied. The following section of this module outlines how the generated check files can be used to review each of the key changes we have made to the model. Note that there is often more than one check file that can be used to review each component of the model. The below steps outline just how some of these check files can be used.

=== Review Created TIN ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_DEM_Z.TIF

The FMT_M02_001_DEM_Z.TIF is a grid of the final zpts used by TUFLOW after processing of each of the layers within the TGC. It can be read by most mainstream GIS software and also visualised in SMS.

=== Review Changes to Roughness ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_grd_check

The grd_check file contains information on all cells within the model extent, such as ZC elevation and the location of the cell in relation to the model origin. One of the attributes of this check layer is the Material ID assigned to each cell. A review of this check file is recommended particularly when using multiple GIS layers to define the roughness of a 2D domain. The file can be colour coded to provide a visual representation of the roughness assigned to the entire model extent by:

*Changing the style of the grd_check file to 'Categorized' by the 'Material' column in QGIS
*By right clicking on the grd_check layer within the table of contents and click Properties. Once the properties dialogue window is open select the Symbology tab. Choose the Unique values option under Categories in the left-hand list and map the Value Field of interest.

=== Review Pipe Network ===
From the TUFLOW\check\1d\ folder open within QGIS:
*FMT_M02_001_nwk_C_check
*FMT_M02_001_nwk_N_check

These two check files provide information on all 1D elements within the model. The _nwk_C_check layer provides information on all 1D channels (including structures) in the model, whilst the _nwk_N_check layer provides information on the nodes. Notice how the _nwk_C check layer shows a series of dashed lines at the locations where we have specified pits in the model. These lines represent 'pit channels', zero length channels that connect the 1D pipe network to the 2D floodplain. Viewing in conjunction with the _nwk_N check layer shows two nodes are created at the upstream (ground level) and downstream (invert of the pipe network) ends of the pit channel.

=== Review Boundaries and 1D/2D Links ===
From the TUFLOW\check\2d\ folder open within QGIS:
*FMT_M02_001_1d_to_2d_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. Where we have digitised the pipe network, this check file shows the SX boundaries that have been created at the location of the pits. This check file also shows the ZC elevation of the SX boundary which can be compared to surrounding ZC elevations by viewing alongside the grd_check layer. The check layer also shows the HX boundaries digitised along the river banks in Module 01.

=== Review Flood Modeller/ESTRY 1D/1D Links ===
The successful connection of the Flood Modeller and ESTRY networks can be checked by the presence of CHECK 1393 messages highlighting the presence of "X1DH" and "X1DQ" links to external nodes within the TUFLOW Log File. Alternatively, the success of the connectivity of the "X1DQ" and "X1DH" links can be assessed through reference to the _messages.SHP/GPKG GIS layer which contains CHECK 1393 at each ESTRY node linked to a Flood Modeller node.

=Review the Results=

Open the 2D results in the TUFLOW results viewer. It can be seen that during the flood event the capacity of the pipe network is exceeded resulting in flooding of the roads in the proposed development. 
[[File:M07 2d Results.PNG|800px]] 
 
The 1D ESTRY results can be viewed by opening the time series results using the approach described in the following page: [[TUFLOW Viewer - Load Results - Time Series]]. You can also open results from Flood Modeller within the TUFLOW Viewer using the instructions here: [[TUFLOW Viewer - Load Results - Time Series FM]]

It can be seen that there is negative flow in Pipe16 and Pipe18 when the water levels in the Flood Modeller node and the connected ESTRY nodes are such that backwater effects are present.
[[File:X1dh.png|alt=X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18|none|thumb|500x500px|X1DH Flows from Estry to Flood Modeller at Pipe 16 and 18]]
A sense check of the flows being transferred across the "X1DQ" link can also be performed by plotting and comparing the flow time series for the first ESTRY node (ds3) and the last Flood Modeller node (ds2).
[[File:X1dq.png|alt=X1DQ Flow from Flood Modeller to Estry at DS3|none|thumb|500x500px|X1DQ Flow from Flood Modeller to Estry at DS3]]

We have now completed the tutorial and you should now be familiar with the approaches of linking Estry to Flood Modeller and vice versa.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model_Provisional| Back to Tutorial Introduction Main Page]]
}}

Flood Modeller Tutorial Module01

2025-12-24T10:14:42Z

RussellGardner:

=Introduction=
In this module, an existing 2D TUFLOW domain is linked to a Flood Modeller 1D model.

The 2D domain represents the floodplain, while the 1D model represents the watercourse and in-channel structures. Linked 1D–2D models combine the strengths of both approaches. Here, the 1D scheme represents the largely unidirectional flow of the watercourse, while the 2D scheme captures the more complex floodplain hydraulics.

In the below 2D model example, the main channel is only 5-10 m wide, making the 5 m grid resolution too coarse to represent it accurately. This reduces the accuracy of conveyance within the channel. 
[[file:Poor_2d_rep.png|400px]] There are several options for improving the representation of this creek channel:
* Decrease the width of the 2D cells, either globally or by using Quadtree, and/or apply sub-grid sampling.
* Model the channel as a 1D network dynamically linked to the 2D domain (the floodplain).
For this module, the second option will be demonstrated.

TUFLOW can also link with other 1D solvers, including ESTRY (TUFLOW 1D), XP-SWMM and 12D Solutions’ Dynamic Drainage. Setting up a channel that cuts through a 2D domain is typically one of the more time-consuming modelling tasks.

For this module, the complete Flood Modeller 1D model network has been provided, to allow for progressing through the module in a relatively short period of time.

===Linking Flood Modeller to TUFLOW===

It is assumed from the outset of this module that Flood Modeller has already been linked to the desired version of TUFLOW. There are four methods by which Flood Modeller and TUFLOW can be linked, all of which are described on this [[Running_linked_Flood_Modeller_-_TUFLOW_Models | page]].

Using the Flood Modeller interface to set the location of the TUFLOW engine files for the TUFLOW build you want to use, is the simplest approach to linking Flood Modeller and TUFLOW and does not duplicate files. This method is recommended if it is expected that the same versions of Flood Modeller and TUFLOW will be used consistently when running linked models.

1) Open the Flood Modeller software and in the 'Home' tab select the 'General' option. 
[[file:FM Home Tab.png|500px]] 

2) Select the 'Project Settings' sub-menu and within the TUFLOW Engine File Location choose to browse to the version of TUFLOW that you would like to link Flood Modeller to. Choose 'Open' and then 'OK'. It is recommended that the option 'Show Solver Window when Running Simulations' be switched on as well. 

[[file:FM TUFLOW Linking 26092025.png|500px]] 

3) Save the changes that you have made to the setup. This will update the settings file (formed.ini).

4) Restart Flood Modeller to effect the revised setting.

4) The linked model can then be run by opening the .ief file within the Flood Modeller Interface and clicking Run. 

=Existing Model Data=
This tutorial builds upon the 2D TUFLOW domain that was constructed as part of [[Tutorial_M01 |Module 1]] and [[Tutorial_M02 |Module 2]] of the TUFLOW Tutorial Model.

The model developed in these tutorial modules already contains some culverts modelled as 1D elements. The culverts are modelled in ESTRY, TUFLOW's internal 1D engine. One of these culverts will be kept in ESTRY and the other will be added to the Flood Modeller model. The 2D boundary conditions (upstream inflows and downstream stage-discharge boundary) will be removed from the model. These will instead be represented in Flood Modeller as it is a more typical schematisation for a 1D/2D linked model.

The existing TUFLOW model consists of:
*Definition of Active/Inactive Areas
*Definition of Land Use areas for the spatial distribution of roughness values
*1D ESTRY culverts
*1D/2D boundary links to connect the 1D ESTRY culverts to the 2D TUFLOW domain.

= Project Initialisation =
TUFLOW models are separated into a series of folders which contain the input and output files. The recommended set up for the model directory and sub-folders is shown below. For a more detailed description, refer to the [https://docs.tuflow.com/classic-hpc/manual/2025.2/FoldersFileTypesandFileNaming-2.html#FoldersFileTypesandFileNaming-2]. 
<ol>
[[File:Tute M01 Directory Structure v3.png|left]]
{| class="wikitable"

! style="background-color:#005581; font-weight:bold; color:white;"| Sub-Folder
! style="background-color:#005581; font-weight:bold; color:white;" width=10%| Input / Output
! style="background-color:#005581; font-weight:bold; color:white;" width=75%| Description
|-
| bc_dbase|| Input || Boundary condition database(s) and input time-series data.
|-
| check|| Output || GIS and other check files to carry out quality control checks (use Write Check Files).
|-
| model|| Input ||Geometry (TGC), Boundary (TBC) and other model control text files (i.e. no GIS files).
|-
| model\gis|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\gis is typically used for all QGIS and ArcGIS files.
|-
| model\mi|| Input || GIS layers that are inputs to the 2D and 1D model domains are contained within this folder, model\mi is typically used for MapInfo formatted GIS files.
|-
| results|| Output|| TUFLOW outputs the results to this folder in specified formats.
|-
| runs|| Input|| TUFLOW Control Files (TCF).
|-
| runs\log|| Output || TUFLOW log files (TLF) and messages layers.
|}
</ol>
The TUFLOW folders can be set up manually, automatically running TUFLOW model with <tt> Write Empty GIS Files </tt> command or automatically through GIS programs:
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS | QGIS - SHP]]
:*[[Tutorial_M01_Configure_TUFLOW_Project_QGIS_GPKG | QGIS - GPKG]]
:*SMS - the folder structure listed above is automatically created before running the model using the 'Export TUFLOW files' command (see [[Run TUFLOW from within SMS | Run TUFLOW from within SMS]]).
:*ArcMap (10.1 and newer) - the ArcTUFLOW Toolbox can be used to automatically create the model folders, model projection, TUFLOW control files and run TUFLOW to create the template files.

The following points on TUFLOW folders and filenames are worth noting:
:*TUFLOW accepts any folder structure, though the above listed format is most commonly used and is recommended. 
:*TUFLOW accepts spaces and special characters (such as ! or #) in filenames and paths, but other software may not. It is recommended that spaces and other special characters are not used in the simulation path and filenames. 
:*Folder paths, filenames, file extensions and TUFLOW commands are not case sensitive in any TUFLOW control files. 
:*Any directories that don't apply can be omitted, for example, if using QGIS or ArcMap the model\mi directory is not required. 
 

= Model Familiarisation=
Become familiar with the model location, using an aerial image and DEM: 
:*[[Model_Familiarisation_QGIS | QGIS]]
 

=GIS and Model Inputs=
The steps required to modify each of the GIS inputs are demonstrated in QGIS using SHP and GPKG formats. Instructions for completing the module in ArcGIS or MapInfo are available on the archive page for [[Flood_Modeller_Tutorial_Module01_Archive |Tutorial Module 01]].

===Define the External 1D Networks===
This part of the module creates the GIS layers that specify the location of the Flood Modeller nodes that are to be connected to the 2D domain.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_x1D_Nodes | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_x1D_Nodes | QGIS - GPKG]]

===Define the Water Level Lines===
This part of the module creates the Water Level Lines that will be used to visualise 1D results in 2D map outputs.

Follow the instructions below for the preferred GIS format.

* [[FM Tutorial M01_QGIS_SHP_WLL_Lines | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_WLL_Lines | QGIS - GPKG]]

===Define the 1D/2D Boundary Links===
This part of the module creates the 1D/2D boundaries to link the Flood Modeller 1D component to the TUFLOW 2D domain.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Links | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Links | QGIS - GPKG]]

===Define Bank Elevations===
This part of the module defines the bank elevations of the watercourse which are the elevations of the 1D/2D boundary links created in the previous section.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_Banks | QGIS - SHP]]
* [[FM Tutorial M01_QGIS_GPKG_Banks | QGIS - GPKG]]

===Deactivate 2D cells ===
This part of the module describes the steps to deactivate the 2D cells where the 1D model is replacing the 2D solution.

Follow the instructions below for the preferred GIS format.
* [[FM Tutorial M01_QGIS_SHP_1D2D_Code | QGIS – SHP ]]
* [[FM Tutorial M01_QGIS_GPKG_1D2D_Code | QGIS - GPKG]]

=Modify Simulation Control Files=

With the input GIS layers modified, the next step is to update the TUFLOW control files and Flood Modeller simulation files to create a linked model.

== TUFLOW Geometry Control File (TGC) ==
At this stage, the following changes will be made to the geometry:
* The cells along the watercourse that are represented in the 1D Flood Modeller component of the model are deactivated.
* Bank elevations along the watercourse are enforced.

<ol>
<li> In the '''FMT_Tutorial\FMT_M01\TUFLOW\model''' folder, save a copy of M01_5m_002.tgc as FMT_M01_001.tgc. </li>

<li> Open FMT_M01_001.tgc 
'''QGIS - SHP''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt>..\model\gis\2d_code_FMT_M01_001_R.shp 
<tt>Read GIS Code BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_R.shp <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R.shp''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R.shp''' deactivates selected cells along the watercourse.

 '''QGIS - GPKG''' 
Add an extra command line after <tt>Read GIS Code </tt><tt>==</tt> 2d_code_FMT_M01_001_R 
<tt>Read GIS Code BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_R <tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt> 
Note that the order of the commands is important. The layer '''2d_code_FMT_M01_001_R''' first activates cells within the modelled area, then the layer '''2d_bc_FMT_M01_HX_001_R''' deactivates selected cells along the watercourse. </li>

<li> Topography amendments should be added in a new section at the bottom of the TGC. These are: 
'''QGIS - SHP''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> gis\2d_bc_FMT_M01_HX_001_L.shp | gis\2d_bc_FMT_M01_HX_001_P.shp <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P.shp''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L.shp''' layer (defining bank location).

 '''QGIS - GPKG''' 
<tt>Read GIS Z HX Line MAX </tt> <tt>==</tt> 2d_bc_FMT_M01_HX_001_L | gis\2d_bc_FMT_M01_HX_001_P <tt>! Defines the bank crest levels (1D/2D boundary cell elevations). The 'MAX' option prevents any zpt elevations from being lowered </tt> 
The two GIS layers must be read in together on the same command line. This tells TUFLOW to associate the points within the '''2d_bc_FMT_M01_HX_001_P''' layer (defining elevation) with the polylines within the '''2d_bc_FMT_M01_HX_001_L''' layer (defining bank location). </li>

<li> Save the file. The geometry control file is now ready to be used. </li>
</ol>

==TUFLOW Boundary Control File (TBC)==
Next, update the TBC to reference the model boundary files created in the previous steps, as described below:

*Add the 1D/2D boundaries that link the Flood Modeller open channel to the 2D floodplain.
*Update the 1D/2D boundaries which link the ESTRY culverts to the 2D floodplain, as some of these culverts are now modelled in Flood Modeller.
*Remove the external inflows applied to the TUFLOW model, as these are now applied in Flood Modeller.

<ol>
<li> Open '''M02_5m_001.tbc''' and save a copy as '''FMT_M01_001.tbc'''.
<li> Remove the boundary linking to the TUFLOW inflows by putting an exclamation mark before the line reading: '''QGIS - SHP''' <tt>Read GIS BC</tt> <tt>== </tt> gis\2d_bc_M01_002_L.shp '''QGIS - GPKG''' <tt>Read GIS BC</tt> <tt>== </tt> 2d_bc_M01_002_L

<li> Add reference to the 1D/2D boundary links that connect Flood Modeller to the 2D floodplain:

 '''QGIS - SHP''' <tt>Read GIS BC </tt> <tt>== </tt> gis\2d_bc_FMT_M01_HX_001_P.shp | gis\2d_bc_FMT_M01_HX_001_L.shp <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt> '''QGIS - GPKG''' <tt>Read GIS BC </tt> <tt>== </tt> 2d_bc_FMT_M01_HX_001_P | 2d_bc_FMT_M01_HX_001_L <tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt><li> Save the file. The boundary control file is now ready to be used.

</ol>

== TUFLOW Control File (TCF) ==
Finally, the TCF is updated as follows:
<ul>
<li>Remove references to model parameters that are read from Flood Modeller.
<li>Read in the GIS layer of the Flood Modeller nodes.
<li>Read in the GIS layers used to create Water Level Lines along the Flood Modeller component of the model (optional).
<li>Add a reference to the ESTRY Control File.
<li>Update references to the TBC and TGC.
</ul>The following steps outline how to apply these updates:

# In the \FMT_Tutorial\FMT_M01\TUFLOW\runs folder, save a copy of the TUFLOW file created as a part of [[Tutorial_M02 |Module 2]] ('''M02_5m_001.tcf''') as '''FMT_M01_001.tcf.'''
# Remove the Start Time, End Time, and 2D Timestep parameters from the TCF, as these are read from the Flood Modeller .ief file in a linked Flood Modeller-TUFLOW model. If they are left in place the Flood Modeller settings will override the TUFLOW settings. This is done by adding an exclamation mark in front of each of the following commands. <tt>! SIMULATION TIME CONTROL COMMANDS</tt> <tt>Timestep </tt> <tt>== </tt> 1.5 <tt>! Specifies a 2D computational timestep of 1.5 seconds </tt> <tt>Start time </tt> <tt>== </tt> 0 <tt>! Specifies a simulation start time of 0 hours</tt> <tt>End Time </tt> <tt>== </tt>3 <tt>! Specifies a simulation end time of 3 hours</tt>
#Read in the GIS layers of the Flood Modeller Nodes. Place the below command line anywhere in the .tcf. It is good practice to create a section within the .tcf to reference all 1D commands: '''QGIS - SHP''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <tt>! GIS layer referencing node IDs from Flood Modeller </tt> '''QGIS - GPKG''' <tt>Read GIS X1D Nodes</tt> <tt>== </tt> 1d_x1d_FMT_M01_nodes_001_P <tt>! GIS layer referencing node IDs from Flood Modeller</tt>
#Add commands to read in the GIS layers referencing Water Level Lines drawn along the Flood Modeller component of the model: '''QGIS - SHP''' <tt>Read GIS X1D Network</tt> <tt>== </tt>..\model\gis\1d_x1d_FMT_M01_nwk_001_L.shp <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> ..\model\gis\1d_x1d_WLL_FMT_M01_001_L.shp <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> '''QGIS - GPKG''' <tt>Read GIS X1D Network</tt> <tt>== </tt> 1d_x1d_FMT_M01_nwk_001_L <tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt> <tt>Read GIS X1D WLL</tt> <tt>== </tt> 1d_x1d_WLL_FMT_M01_001_L <tt>! GIS layer containing WLLs for visualising 1D results in 2D (optional)</tt> The addition of TUFLOW Water Level Lines (WLL) allows the Flood Modeller 1D results to be visualised within the TUFLOW 2D map outputs. They provide a means by which to remove the gaps in the map outputs where the 1D Flood Modeller domains are located and the 2D cells are deactivated. To do this, TUFLOW requires a 1D_WLL layer to define the cross sections locations, and a 1d_nwk layer that defines the river centre line. The layers are not used in the hydraulic calculations and their inclusion is not always required. The Dist_for_Add_Points determines the intervals in metres at which interpolation points are inserted along each WLL.
#Add commands to read in an ESTRY Control File which contains references to some of the culverts present on the floodplain: <tt>ESTRY Control File</tt> <tt>== </tt>..\model\FMT_M01_001.ecf <tt>!Reference the ESTRY Control File </tt>
#Update the links to the Geometry control file, the Boundary Condition control file and the bc_dbase file: <tt>Geometry Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tgc <tt>BC Control File</tt> <tt>== </tt>..\model\FMT_M01_001.tbc <tt>BC Database</tt> <tt>== </tt>..\bc_dbase\bc_dbase_FMT_M01.csv
</ol>
This concludes the changes needed to be made to the TCF.

=Flood Modeller Simulation Files=
A complete Flood Modeller model is provided in the '''FMT_M01\Flood_Modeller''' folder. The model files are located in the DAT, IED and IEF folders.

The DAT and IED files are complete and do not require modification to link with TUFLOW. The IEF file must be altered to create the link. These alterations can be made in a text editor or in the Flood Modeller interface.

The instructions below are written for Flood Modeller interface version 7.2.

===IEF File===
<ul>
<li> Open Flood Modeller. Select 'Load 1D Network'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\DAT''' and load the '''FMT_M01_001.dat'''.</li>
<li> Right click 'Event Data' and select 'Add Item'. Navigate to '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' and load the '''FMT_Inflows.IED'''.</li>

<li> On the 'Simulation' tab, click New 1D Simulation. Save the file when prompted in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IEF''' folder as '''FMT_M01_001.ief'''</li>
<li> On the 'Files' Tab of the simulation window, set the following parameters:</li>
*Event Title: FMT_M01_001
*1D Data File: The full path to the \FMT_Tutorial\FMT_M01\Flood_Modeller\DAT\FMT_M01_001.dat
*Use Initial Conditions from: Network File (.dat)
*Results File: set the full path to \FMT_Tutorial\FMT_M01\Flood_Modeller\RES\FMT_M01_001.
[[File:Ief file.png|frameless|500x500px]]
<li>To the right of the Event Data box, click Add and select the '''FMT_Inflows.IED''' file in the '''\FMT_Tutorial\FMT_M01\Flood_Modeller\IED''' folder.</li>

<li>On the 'Times' tab, replace the simulation time parameters that were removed from TUFLOW. Enter the following parameters:</li>
*Run Type: Unsteady (Fixed Timestep)
*Start Time (hrs): 0
*Finish Time (hrs): 3
*Timestep (s):1
*Save Interval (s): 300.
[[File:Ief time.png|frameless|500x500px]]

<li> Add the 'Links' tab by clicking View> Tabs > Links. On the 'Links' tab, enter the following parameters:
*2-d Scheme: TUFLOW
*2-d Timestep: 2
*Check the box for ‘Perform corrective 1D timestep’
*2-d control file: full path to the '''FMT_M01_001.tcf''' from the '''\FMT_Tutorial\FMT_M01\TUFLOW\runs''' folder.
[[File:Ief tcf.png|frameless|500x500px]]
</li></li><li></li><li> Save the Scenario Data and run the Flood Modeller simulation. </li>{{Video|name=Setting up FMP IEF Simulation File.mp4 |width=1123}}</ul>

= Review Check Files =

=== Review Boundaries and 1D/2D Links ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M02_001_1d_to_2d_check
*FMT_M02_001_sac_check

The _1d_to_2d_check layer highlights the location of all 1D/2D boundary links within the model. In this case it should show the HX boundaries that have been digitised along the river banks.

The _sac_check layer highlights the lowest 2d cells within the SA boundary polygon to which inflow is first distributed.

=== Review Bank Elevations ===

From the TUFLOW\check\2d\ folder open within QGIS:

*FMT_M01_001_zln_zpt_check_P

The _zln_zpt_check layer highlights the cells whose elevations have been modified by z lines to represent the bank crests of the watercourse.

= Review the Results =
Instructions for viewing the TUFLOW mesh (XMDF) and 1D time series (.tpc) outputs are provided in [[Tutorial_M01_Results_QGIS | Module 1]] and [[Tutorial_M03_Results_QGIS | Module 3.]] It is often useful to view 1D Flood Modeller results alongside 2D TUFLOW map outputs. The Flood Modeller results can be opened in QGIS with the TUFLOW Viewer plugin, together with the TUFLOW mesh results, by following the linked instructions. Alternatively, the TUFLOW mesh results can be loaded directly into the Flood Modeller Pro interface.

The video below demonstrates both methods:
*[[TUFLOW Viewer - Load Results - Time Series FM|Loading Flood Modeller 1D results]] in QGIS using the TUFLOW Viewer plugin.
*Loading TUFLOW mesh results in Flood Modeller Pro.
{{Video|name=Viewing Results in Flood Modeller and TUFLOW.mp4.mp4 |width=1123}}

= Troubleshooting =

=== Troubleshooting for HPC Simulation ===

If the following error message is encountered when running the TUFLOW HPC model:

<pre>ERROR 3999 - ptx file version mismatch
</pre>

Please ensure that the four TUFLOW kernel files below have been transferred from your TUFLOW engine folder into your Flood Modeller "bin" folder.

*hpcKernels_nSP.ptx
*hpcKernels_nDP.ptx
*qpcKernels_nSP.ptx
*qpcKernels_nDP.ptx

=== Troubleshooting for GPU Simulation ===
If the following error is encountered when running the TUFLOW HPC model using GPU hardware: :
<pre>TUFLOW GPU: Interrogating CUDA enabled GPUs …
TUFLOW GPU: Error: Non-CUDA Success Code returned
</pre>
or
<pre>ERROR 2785 - No GPU devices found, enabled or compatible.
</pre>
Please try the following steps:
<ol>
<li> Check if the GPU card is an NVIDIA GPU card. Currently, TUFLOW does not run on AMD type GPU.
<li> Check if the NVIDIA GPU card is CUDA enabled and whether the latest drivers are installed (see [[GPU_Setup |GPU Setup)]].
</ol>If an issue not described above is encountered, an email should be sent to [mailto:support@tuflow.com support@tuflow.com]. 

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Model_Provisional| Back to Tutorial Introduction Main Page]]
}}

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-16T14:14:30Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1 V3.mp4 |width=1123}}
 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2 V2.mp4 |width=1123}}
 
<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer '''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3 V2.mp4 |width=1123}}
 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

File:FMP ESTRY 1D Link Module 02 QGIS SHP Part3 V2.mp4

2025-10-16T14:14:25Z

RussellGardner:

n/a

File:FMP ESTRY 1D Link Module 02 QGIS SHP Part2 V2.mp4

2025-10-16T14:12:47Z

RussellGardner:

n/a

File:FMP ESTRY 1D Link Module 02 QGIS SHP Part1 V3.mp4

2025-10-16T14:11:57Z

RussellGardner:

n/a

FM Tutorial M02 QGIS GPKG Flood Modeller1D/ESTRY 1D Link

2025-10-16T14:08:44Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an "X1DH" link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L''' from the '''FMT_M01_002.gpkg''' into QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Open the layers'''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within QGIS. These layers are located within the '''Module_data\Module_02\Creek ''' folder.
<li>Drag and drop the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel.
<li>Close the three GIS layers in the Layers Panel and reload them from the project GeoPackage file '''FMT_M01_002.gpkg'''.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 GPKG SHP Part1 V3.mp4 |width=1123}}
 

<li>Open the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS. It is located within the '''Module_data\Module_02\Creek''' folder.
<li>Drag and drop the layer into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel. Close the layer in the Layers Panel.
<li>Reload the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS from the project GeoPackage file. Turn on Toggle Editing mode and open Field Calculator. Select the field "Source" from the "Update Existing Field" dropdown and enter the expression <nowiki/>'..\\xs\\' ||source to prepend "..\\xs\\" to all rows for this field. The results will be the Source will be set up as per the below image which will ensure that the locations of the csv files are correctly referenced.
 [[File:Source.png|frameless|300x300px]] 
<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:

 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part2 V2.mp4 |width=1123}}
 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type has been added to connect them. This is present within the '''1d_nwk_FMT_M02_channels_001_L layer.''' This must be digitised from the ESTRY channel (from the first vertex on the polyline) to the Flood Modeller node.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.gpkg with the name '''1d_nwke_X1DQ_P''' into the project GeoPackage file '''FMT_M01_002.gpkg'''
<li>Open the layer '''1d_nwke_X1DQ_P''' and turn on Toggle Editing. Add the attribute values shown in the table below. Save the layer.
{| class="wikitable" align="center" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;" | Attribute
! style="background-color:#005581; font-weight:bold; color:white;" | Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part3 V2.mp4 |width=1123}}

 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel is present and a 1d_nwke_P layer has been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

File:FMP ESTRY 1D Link Module 02 QGIS GPKG Part3 V2.mp4

2025-10-16T14:08:21Z

RussellGardner:

n/a

File:FMP ESTRY 1D Link Module 02 QGIS GPKG Part2 V2.mp4

2025-10-16T14:07:03Z

RussellGardner:

n/a

FM Tutorial M02 QGIS GPKG Flood Modeller1D/ESTRY 1D Link

2025-10-16T13:39:35Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an "X1DH" link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L''' from the '''FMT_M01_002.gpkg''' into QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Open the layers'''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within QGIS. These layers are located within the '''Module_data\Module_02\Creek ''' folder.
<li>Drag and drop the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel.
<li>Close the three GIS layers in the Layers Panel and reload them from the project GeoPackage file '''FMT_M01_002.gpkg'''.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 GPKG SHP Part1 V3.mp4 |width=1123}}
 

<li>Open the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS. It is located within the '''Module_data\Module_02\Creek''' folder.
<li>Drag and drop the layer into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel. Close the layer in the Layers Panel.
<li>Reload the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS from the project GeoPackage file. Turn on Toggle Editing mode and open Field Calculator. Select the field "Source" from the "Update Existing Field" dropdown and enter the expression <nowiki/>'..\\xs\\' ||source to prepend "..\\xs\\" to all rows for this field. The results will be the Source will be set up as per the below image which will ensure that the locations of the csv files are correctly referenced.
 [[File:Source.png|frameless|300x300px]] 
<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:

 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type has been added to connect them. This is present within the '''1d_nwk_FMT_M02_channels_001_L layer.''' This must be digitised from the ESTRY channel (from the first vertex on the polyline) to the Flood Modeller node.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.gpkg with the name '''1d_nwke_X1DQ_P''' into the project GeoPackage file '''FMT_M01_002.gpkg'''
<li>Open the layer '''1d_nwke_X1DQ_P''' and turn on Toggle Editing. Add the attribute values shown in the table below. Save the layer.
{| class="wikitable" align="center" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;" | Attribute
! style="background-color:#005581; font-weight:bold; color:white;" | Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel is present and a 1d_nwke_P layer has been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

File:FMP ESTRY 1D Link Module 02 GPKG SHP Part1 V3.mp4

2025-10-16T13:39:23Z

RussellGardner:

n/a

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-16T12:15:35Z

RussellGardner:

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer '''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-16T12:07:10Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1 V2.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer '''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3 01.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS GPKG Flood Modeller1D/ESTRY 1D Link

2025-10-16T09:39:12Z

RussellGardner:

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an "X1DH" link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L''' from the '''FMT_M01_002.gpkg''' into QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Open the layers'''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within QGIS. These layers are located within the '''Module_data\Module_02\Creek ''' folder.
<li>Drag and drop the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel.
<li>Close the three GIS layers in the Layers Panel and reload them from the project GeoPackage file '''FMT_M01_002.gpkg'''.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part1.mp4 |width=1123}}
 

<li>Open the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS. It is located within the '''Module_data\Module_02\Creek''' folder.
<li>Drag and drop the layer into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel. Close the layer in the Layers Panel.
<li>Reload the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS from the project GeoPackage file. Turn on Toggle Editing mode and open Field Calculator. Select the field "Source" from the "Update Existing Field" dropdown and enter the expression <nowiki/>'..\\xs\\' ||source to prepend "..\\xs\\" to all rows for this field. The results will be the Source will be set up as per the below image which will ensure that the locations of the csv files are correctly referenced.
 [[File:Source.png|frameless|300x300px]] 
<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:

 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part2.mp4 |width=1123}}
 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type has been added to connect them. This is present within the '''1d_nwk_FMT_M02_channels_001_L layer.''' This must be digitised from the ESTRY channel (from the first vertex on the polyline) to the Flood Modeller node.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.gpkg with the name '''1d_nwke_X1DQ_P''' into the project GeoPackage file '''FMT_M01_002.gpkg'''
<li>Open the layer '''1d_nwke_X1DQ_P''' and turn on Toggle Editing. Add the attribute values shown in the table below. Save the layer.
{| class="wikitable" align="center" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;" | Attribute
! style="background-color:#005581; font-weight:bold; color:white;" | Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part3.mp4 |width=1123}}
 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel is present and a 1d_nwke_P layer has been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS GPKG Flood Modeller1D/ESTRY 1D Link

2025-10-16T09:30:57Z

RussellGardner:

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an "X1DH" link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L''' from the '''FMT_M01_002.gpkg''' into QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Open the layers'''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within QGIS. These layers are located within the '''Module_data\Module_02\Creek ''' folder.
<li>Drag and drop the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel.
<li>Close the three GIS layers in the Layers Panel and reload them from the project GeoPackage file '''FMT_M01_002.gpkg'''.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part1.mp4 |width=1123}}
 

<li>Open the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS. It is located within the '''Module_data\Module_02\Creek''' folder.
<li>Drag and drop the layer into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel. Close the layer in the Layers Panel.
<li>Reload the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS from the project GeoPackage file. Turn on Toggle Editing mode and open Field Calculator. Select the field "Source" from the "Update Existing Field" dropdown and enter the expression <nowiki/>'..\\xs\\' ||source to prepend "..\\xs\\" to all rows for this field. The results will be the Source will be set up as per the below image which will ensure that the locations of the csv files are correctly referenced.
 [[File:Source.png|frameless|300x300px]] 
<li>Copy the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\gis''' folder. These csv files will be used to define the geometry of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:

 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part2.mp4 |width=1123}}
 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type has been added to connect them. This is present within the '''1d_nwk_FMT_M02_channels_001_L layer.''' This must be digitised from the ESTRY channel (from the first vertex on the polyline) to the Flood Modeller node.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.gpkg with the name '''1d_nwke_X1DQ_P''' into the project GeoPackage file '''FMT_M01_002.gpkg'''
<li>Open the layer '''1d_nwke_X1DQ_P''' and turn on Toggle Editing. Add the attribute values shown in the table below. Save the layer.
{| class="wikitable" align="center" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;" | Attribute
! style="background-color:#005581; font-weight:bold; color:white;" | Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part3.mp4 |width=1123}}
 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel is present and a 1d_nwke_P layer has been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS GPKG Flood Modeller1D/ESTRY 1D Link

2025-10-16T09:09:12Z

RussellGardner:

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an "X1DH" link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L''' from the '''FMT_M01_002.gpkg''' into QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Open the layers'''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within QGIS. These layers are located within the '''Module_data\Module_02\Creek ''' folder.
<li>Drag and drop the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel.
<li>Close the three GIS layers in the Layers Panel and reload them from the project GeoPackage file '''FMT_M01_002.gpkg'''.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part1.mp4 |width=1123}}
 

<li>Open the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS. It is located within the '''Module_data\Module_02\Creek''' folder.
<li>Drag and drop the layer into the project GeoPackage file '''FMT_M01_002.gpkg''' in the Browser Panel. Close the layer in the Layers Panel.
<li>Reload the layer '''1d_xs_FMT_M02_creek_001_L''' within QGIS from the project GeoPackage file. Turn on Toggle Editing mode and open Field Calculator. Select the field "Source" from the "Update Existing Field" dropdown and enter the expression <nowiki/>'..\\xs\\' ||source to prepend "..\\xs\\" to all rows for this field. The results will be the Source will be set up as per the below image which will ensure that the locations of the csv files are correctly referenced.
 [[File:Source.png|frameless|300x300px]] 
<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files will be used to define the geometry of the river channel cross sections.
*ds_weir.csv
*ds1.csv
*ds2.csv
*ds3.csv
*ds4.csv
*ds5.csv
*ds5_weir.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:

 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part2.mp4 |width=1123}}
 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type has been added to connect them. This is present within the '''1d_nwk_FMT_M02_channels_001_L layer.''' This must be digitised from the ESTRY channel (from the first vertex on the polyline) to the Flood Modeller node.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.gpkg with the name '''1d_nwke_X1DQ_P''' into the project GeoPackage file '''FMT_M01_002.gpkg'''
<li>Open the layer '''1d_nwke_X1DQ_P''' and turn on Toggle Editing. Add the attribute values shown in the table below. Save the layer.
{| class="wikitable" align="center" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;" | Attribute
! style="background-color:#005581; font-weight:bold; color:white;" | Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS GPKG Part3.mp4 |width=1123}}
 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel is present and a 1d_nwke_P layer has been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T16:24:55Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer '''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3 01.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

File:FMP ESTRY 1D Link Module 02 QGIS SHP Part3 01.mp4

2025-10-07T16:24:35Z

RussellGardner:

n/a

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T16:00:30Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer '''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T15:48:37Z

RussellGardner: /* Conclusion */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer'''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Modify Simulation Control Files| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T15:45:20Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_L.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds3.csv
*ds4.csv
*ds5.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer'''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T15:28:24Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_002_P.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds1.csv
*ds2.csv
*ds3.csv
*ds4.csv
*ds5.csv
*ds5_weir.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer'''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Flood Modeller1D/ESTRY 1D Link

2025-10-07T15:17:49Z

RussellGardner: /* Method */

=Introduction=

This page describes the method in QGIS for linking TUFLOW 1D ESTRY networks to a 1D river channel represented within Flood Modeller. Firstly, a pipe network represented in ESTRY will be linked to Flood Modeller using an X1DH link. The Flood Modeller 1D network will then be extended downstream by connecting it to an ESTRY river network using an "X1DQ" link.

=Method=
<ol>
<li> Open the layers '''1d_x1d_FMT_M01_nwk_001_P.shp''', '''1d_x1d_FMT_M01_nodes_001_P''', and '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS.
<li>Observe that Pipe16 and Pipe18 in the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' representing the pipe network have been snapped to node “FC01.11” of the layer '''1d_x1d_FMT_M01_nodes_002_P.shp'''. As an additional node hasn’t been manually added the Flood Modeller-ESTRY link at this location is assumed to be an “X1DH” link. If you open the attribute table you will be able to see that the Conn_1D_2D attribute for “Pipe16” and “Pipe18” has been left blank as an “X1DH” link is used by default and therefore doesn’t need to be specified.
<li>Open the Flood Modeller network (.DAT) file '''FMT_M01_002.dat''' in the Flood Modeller Pro interface. Observe that the updated network file terminates at a stage-time boundary unit named “DSBDY”. This does not need to contain any time-varying data as this data will be overridden by the water levels provided by ESTRY.
<li>Copy the GIS layers '''1d_x1d_FMT_M01_nodes_002_P.shp''', '''1d_bc_FMT_m02_001_P.shp''', and '''1d_nwk_FMT_M02_channels_001_L.shp''' within '''Module_data\Module_02\Creek ''' into the '''TUFLOW\model\gis''' folder.
<li>The GIS layer '''1d_nwk_FMT_M02_channels_001_L.shp''' represents the open channel ESTRY network downstream of the Flood Modeller network. A stage-time boundary named "DS_BC" has been set up at the downstream end of the ESTRY network in layer '''1d_bc_FMT_m02_001_P.shp'''.
<li>Observe that an additional node "DSBDY" is present within the updated Read GIS ISIS Nodes layer '''1d_x1d_FMT_M01_nodes_002_P.shp''' at the downstream end of the Flood Modeller network.

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part1.mp4 |width=1123}} 

<li>Create a new folder entitled '''xs''' in the '''TUFLOW\model''' folder. Copy the layer '''1d_xs_FMT_M02_creek_001_L.shp''' and the csv files listed below from the '''Module_data\Module_02\Creek''' folder into the newly created '''TUFLOW\model\xs''' folder. These csv files in combination with the layer '''1d_xs_FMT_M02_creek_001_L.shp''' will be used to define the geometry and locations of the river channel cross sections.
*ds_weir.csv
*ds1.csv
*ds2.csv
*ds3.csv
*ds4.csv
*ds5.csv
*ds5_weir.csv
<li>Copy the csv file '''Weir_HT.csv''' from the '''Module_data\Module_02\Creek''' folder to the '''TUFLOW\bc_dbase''' folder. This csv file contains the stage time data that will be applied at the downstream boundary node 'DS_BC'. A constant stage value of 35.5m AOD has been applied .
<li>An additional row needs to be added to '''bc_dbase_FMT_M02.csv''' to apply the stage-time values from '''Weir_HT.csv'''. The revised bc_dbase should look like the figure below:
 
 
[[File:Bc dbase FMT M01 update.jpg||1200px]] 
 

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part2.mp4 |width=1123}} 

<li>As there is gap between the final node of the Flood Modeller network and the start of the ESTRY network a connector "X" type channel type must be digitised to connect them. Turn on Toggle Editing for the layer'''1d_nwk_FMT_M02_channels_001_'''L and digitise a polyline from the first vertex of the ESTRY channel to the Flood Modeller node. Specify the Type "X" for the digitised channel. Save the changes.
<li>To complete the "X1DQ" link a manually created ESTRY node must be snapped to the Flood Modeller node and have a "Conn_1D_2D" attribute of "X1DQ" specified. To do this, import an empty 1d_nwke_empty_P.shp layer from within the FMT_tutorial\FMT_M02\TUFLOW\model\gis\empty folder.
<li>Save the empty layer as '''1d_nwke_X1DQ_P.shp''' in the '''TUFLOW\model\gis folder'''.
<li>Turn on Toggle Editing for the layer '''1d_nwke_X1DQ_P.shp''' and add the attribute values shown in the table below.
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| ID || ds2 (remember that Flood Modeller is case sensitive)
|-
| Type || Node
|-
| Conn_1D_2D || X1DQ
|}

 {{Video|name= FMP ESTRY 1D Link Module 02 QGIS SHP Part3.mp4 |width=1123}} 

=Conclusion=

The ESTRY pipe network for the proposed development has been connected via an "X1DH" link to discharge via two pipes into the Flood Modeller network by snapping together the nodes in a 1d_nwk_L layer to a node in the 1d_x1d_P layer. A 1d_nwk_L layer has been added to represent the open channel network downstream of the Flood Modeller network in ESTRY. The cross section data for this open channel network has been defined by adding a 1d_xs_L layer with links to the source csv files at every cross section location. A connector "X" type channel and a 1d_nwke_P layer have been added to connect the ESTRY and Flood Modeller open channel networks via an "X1DQ" link. Please return to the main page of the[[Flood Modeller Tutorial Module02_Provisional#Modify Simulation Control Files | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:07:32Z

RussellGardner:

<ol>
=Introduction=
This page details the method for using QGIS to create the GIS based boundary layer. The layer will be populated with the name of each inflow boundary which will be linked to the boundary database in the following steps of this module. The created boundary will be applied as a source-area boundary in a 2d_sa layer. 
=Method=
'''Boundary Condition Database'''
<li>Copy the file '''100yr2hr_loc.csv''' from '''Module_data\Module_02\Inflow''' and place it into the '''TUFLOW\bc_dbase''' folder. This file contains the four hydrographs that will be used.
<li>Open up the latest version of the boundary condition database. This is located within the '''TUFLOW\bc_dbase folder''' and is called '''bc_dbase_FMT_M01.csv'''.
<li>We need to add four additional rows to the file which reference four additional inflows. The revised bc_dbase should look like the figure below: 
 
[[File:100yr2hr_loc_csv.png]] 
 
The hydrographs applied to each of the 2d_sa polygons are contained within the source file '''100yr2hr_loc.csv'''. 
[[File:100yr2hr loc.PNG|800px]]
 
<li>Save the bc_dbase as '''bc_dbase_FMT_M02.csv'''. It is now ready to be used within the model.
 
<li>Copy the layer '''2d_sa_FMT_M02_001_R.shp''' within the '''Module_data\Module_02\Inflow''' folder into the '''TUFLOW\model\gis''' folder.
<li>Open the layer in QGIS. Four polygons have been digitised over the location of the proposed development. Each polygon represents a sub-catchment to which different inflow boundaries will be associated.
<li>Turn on Toggle Editing mode. Populate the first and only attribute of each polygon with the name of the inflow boundary as in the image below. These boundary names will be linked to those specified in the steps above using the bc_dbase located in '''TUFLOW\bc_dbase''' . 
 
[[File:M07 SA polygons QGIS.png|700px]]

 {{Video|name= Define_Boundary_Conditions_Module_02_QGIS_SHP.mp4 |width=1123}} 

<li>Save the layer '''2d_sa_FMT_M02_001_R'''. 

=Conclusion=
 A GIS layer has been created containing four polygons in a 2d_sa layer over the location of the proposed development. The existing boundary conditions database (bc_dbase) has been modified to link these four GIS objects to hydrographs within an external csv file.

 {{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Flood Modeller 1D/ESTRY 1D Link| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:06:13Z

RussellGardner: /* Conclusion */

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:06:03Z

RussellGardner: /* Conclusion */

<ol>
=Introduction=
This page details the method for using QGIS to create the GIS based boundary layer. The layer will be populated with the name of each inflow boundary which will be linked to the boundary database in the following steps of this module. The created boundary will be applied as a source-area boundary in a 2d_sa layer. 
=Method=
'''Boundary Condition Database'''
<li>Copy the file '''100yr2hr_loc.csv''' from '''Module_data\Module_02\Inflow''' and place it into the '''TUFLOW\bc_dbase''' folder. This file contains the four hydrographs that will be used.
<li>Open up the latest version of the boundary condition database. This is located within the '''TUFLOW\bc_dbase folder''' and is called '''bc_dbase_FMT_M01.csv'''.
<li>We need to add four additional rows to the file which reference four additional inflows. The revised bc_dbase should look like the figure below: 
 
[[File:100yr2hr_loc_csv.png]] 
 
The hydrographs applied to each of the 2d_sa polygons are contained within the source file '''100yr2hr_loc.csv'''. 
[[File:100yr2hr loc.PNG|800px]]
 
<li>Save the bc_dbase as '''bc_dbase_FMT_M02.csv'''. It is now ready to be used within the model.
 
<li>Copy the layer '''2d_sa_FMT_M02_001_R.shp''' within the '''Module_data\Module_02\Inflow''' folder into the '''TUFLOW\model\gis''' folder.
<li>Open the layer in QGIS. Four polygons have been digitised over the location of the proposed development. Each polygon represents a sub-catchment to which different inflow boundaries will be associated.
<li>Turn on Toggle Editing mode. Populate the first and only attribute of each polygon with the name of the inflow boundary as in the image below. These boundary names will be linked to those specified in the steps above using the bc_dbase located in '''TUFLOW\bc_dbase''' . 
 
[[File:M07 SA polygons QGIS.png|700px]]

 {{Video|name= Define_Boundary_Conditions_Module_02_QGIS_SHP.mp4 |width=1123}} 

<li>Save the layer '''2d_sa_FMT_M02_001_R'''. 

=Conclusion=
 A GIS layer has been created containing four polygons in a 2d_sa layer over the location of the proposed development. The existing boundary conditions database (bc_dbase) has been modified to link these four GIS objects to hydrographs within an external csv file. Please return to the main page of the [[Flood Modeller Tutorial Module02_Provisional#Flood Modeller 1D/ESTRY 1D Link | Flood Modeller Tutorial 2]].

 {{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:05:47Z

RussellGardner: /* Method */

<ol>
=Introduction=
This page details the method for using QGIS to create the GIS based boundary layer. The layer will be populated with the name of each inflow boundary which will be linked to the boundary database in the following steps of this module. The created boundary will be applied as a source-area boundary in a 2d_sa layer. 
=Method=
'''Boundary Condition Database'''
<li>Copy the file '''100yr2hr_loc.csv''' from '''Module_data\Module_02\Inflow''' and place it into the '''TUFLOW\bc_dbase''' folder. This file contains the four hydrographs that will be used.
<li>Open up the latest version of the boundary condition database. This is located within the '''TUFLOW\bc_dbase folder''' and is called '''bc_dbase_FMT_M01.csv'''.
<li>We need to add four additional rows to the file which reference four additional inflows. The revised bc_dbase should look like the figure below: 
 
[[File:100yr2hr_loc_csv.png]] 
 
The hydrographs applied to each of the 2d_sa polygons are contained within the source file '''100yr2hr_loc.csv'''. 
[[File:100yr2hr loc.PNG|800px]]
 
<li>Save the bc_dbase as '''bc_dbase_FMT_M02.csv'''. It is now ready to be used within the model.
 
<li>Copy the layer '''2d_sa_FMT_M02_001_R.shp''' within the '''Module_data\Module_02\Inflow''' folder into the '''TUFLOW\model\gis''' folder.
<li>Open the layer in QGIS. Four polygons have been digitised over the location of the proposed development. Each polygon represents a sub-catchment to which different inflow boundaries will be associated.
<li>Turn on Toggle Editing mode. Populate the first and only attribute of each polygon with the name of the inflow boundary as in the image below. These boundary names will be linked to those specified in the steps above using the bc_dbase located in '''TUFLOW\bc_dbase''' . 
 
[[File:M07 SA polygons QGIS.png|700px]]

 {{Video|name= Define_Boundary_Conditions_Module_02_QGIS_SHP.mp4 |width=1123}} 

<li>Save the layer '''2d_sa_FMT_M02_001_R'''. 

=Conclusion=
A GIS layer has been created containing four polygons in a 2d_sa layer over the location of the proposed development. The existing boundary conditions database (bc_dbase) has been modified to link these four GIS objects to hydrographs within an external csv file. Please return to the main page of the [[Flood Modeller Tutorial Module02_Provisional#Flood Modeller 1D/ESTRY 1D Link | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:04:17Z

RussellGardner: /* Method */

<ol>
=Introduction=
This page details the method for using QGIS to create the GIS based boundary layer. The layer will be populated with the name of each inflow boundary which will be linked to the boundary database in the following steps of this module. The created boundary will be applied as a source-area boundary in a 2d_sa layer. 
=Method=
'''Boundary Condition Database'''
<li>Copy the file '''100yr2hr_loc.csv''' from '''Module_data\Module_02\Inflow''' and place it into the '''TUFLOW\bc_dbase''' folder. This file contains the four hydrographs that will be used.
<li>Open up the latest version of the boundary condition database. This is located within the '''TUFLOW\bc_dbase folder''' and is called '''bc_dbase_FMT_M01.csv'''.
<li>We need to add four additional rows to the file which reference four additional inflows. The revised bc_dbase should look like the figure below: 
 
[[File:100yr2hr_loc_csv.png]] 
 
The hydrographs applied to each of the 2d_sa polygons are contained within the source file '''100yr2hr_loc.csv'''. 
[[File:100yr2hr loc.PNG|800px]]
 
<li>Save the bc_dbase as '''bc_dbase_FMT_M02.csv'''. It is now ready to be used within the model.
 
<li>Copy the layer '''2d_sa_FMT_M02_001_R.shp''' within the '''Module_data\Module_02\Inflow''' folder into the '''TUFLOW\model\gis''' folder.
<li>Open the layer in QGIS. Four polygons have been digitised over the location of the proposed development. Each polygon represents a sub-catchment to which different inflow boundaries will be associated.
<li>Turn on Toggle Editing mode. Populate the first and only attribute of each polygon with the name of the inflow boundary as in the image below. The next steps of this module will link these boundary names with an inflow using the bc_dbase located in '''TUFLOW\bc_dbase''' . 
 
[[File:M07 SA polygons QGIS.png|700px]]

 {{Video|name= Define_Boundary_Conditions_Module_02_QGIS_SHP.mp4 |width=1123}} 

<li>Save the layer '''2d_sa_FMT_M02_001_R'''. 

=Conclusion=
A GIS layer has been created containing four polygons in a 2d_sa layer over the location of the proposed development. The existing boundary conditions database (bc_dbase) has been modified to link these four GIS objects to hydrographs within an external csv file. Please return to the main page of the [[Flood Modeller Tutorial Module02_Provisional#Flood Modeller 1D/ESTRY 1D Link | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Boundary Conditions

2025-10-07T15:00:10Z

RussellGardner: /* Method */

<ol>
=Introduction=
This page details the method for using QGIS to create the GIS based boundary layer. The layer will be populated with the name of each inflow boundary which will be linked to the boundary database in the following steps of this module. The created boundary will be applied as a source-area boundary in a 2d_sa layer. 
=Method=
'''Boundary Condition Database'''
<li>Copy the file '''100yr2hr_loc.csv''' from '''Module_data\Module_02\Inflow''' and place it into the '''TUFLOW\bc_dbase''' folder. This file contains the four hydrographs that will be used.
<li>Open up the latest version of the boundary condition database. This is located within the '''TUFLOW\bc_dbase folder''' and is called '''bc_dbase_FMT_M01.csv'''.
<li>We need to add four additional rows to the file which reference four additional inflows. The revised bc_dbase should look like the figure below: 
 
[[File:100yr2hr_loc_csv.png]] 
 
The hydrographs applied to each of the 2d_sa polygons are contained within the source file '''100yr2hr_loc.csv'''. 
[[File:100yr2hr loc.PNG|800px]]
 
<li>Save the bc_dbase as '''bc_dbase_FMT_M02.csv'''. It is now ready to be used within the model.
 
<li>Copy the layer '''2d_sa_FMT_M02_001_R.shp''' within the '''Module_data\Module_02\Inflow''' folder into the '''TUFLOW\model\gis''' folder.
<li>Open the layer in QGIS. Four polygons have been digitised over the location of the proposed development. Each polygon represents a sub-catchment to which different inflow boundaries will be associated.
<li>Turn on Toggle Editing mode. Populate the first and only attribute of each polygon with the name of the inflow boundary . The next steps of this module will link these boundary names with an inflow using the bc_dbase located in '''TUFLOW\bc_dbase''' . 
 
[[File:M07 SA polygons QGIS.png|700px]]

 {{Video|name= Define_Boundary_Conditions_Module_02_QGIS_SHP.mp4 |width=1123}} 

<li>Save the layer '''2d_sa_FMT_M02_001_R'''. 

=Conclusion=
A GIS layer has been created containing four polygons in a 2d_sa layer over the location of the proposed development. The existing boundary conditions database (bc_dbase) has been modified to link these four GIS objects to hydrographs within an external csv file. Please return to the main page of the [[Flood Modeller Tutorial Module02_Provisional#Flood Modeller 1D/ESTRY 1D Link | Flood Modeller Tutorial 2]].

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}

</ol>

FM Tutorial M02 QGIS SHP Pipe Network

2025-10-07T14:41:35Z

RussellGardner:

<ol>
=Introduction=
This page describes the method for using QGIS to create the GIS based layers representing the pipe network. Two layers will be created each representing the culverts and pits. The pipe network will be connected to the 2D model domain and and a depth-discharge relationship defined at the pits via the creation of a Pit Inlet Database. 

=Method=
<li>Copy the GIS layers '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp''' within '''Module_data\Module_02\Pipe_Network''' into the '''TUFLOW\model\gis''' folder.
<li>Open the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS. This contains polylines representing the culverts that make up the pipe network.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pipes_001_L.shp''' layer have not been populated. Turn on Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Make use of the ‘'Update All'’ function as previously explained to update all objects at the same time. 

{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || C
|-
| n_or_n_F || 0.015
|-
| US_Invert || -99999
|-
| DS_Invert || -99999
|-
| Number_of || 1
|}
 
The attributes are described completely in [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] of the TUFLOW Manual. The attributes that we have populated, define: 
*The 1d_nwk type. In this case, we have specified culverts with a circular shape.
*The Manning’s n value of the culvert.
*The upstream invert level of the pipes. When -99,999 is specified, the invert level will be taken from a manually created node or pit at the upstream end of the culvert. Refer to the next steps in this module which describe where these inverts will be defined by creating pits.
*The downstream invert level of the pipes. The same rules as for the upstream invert applies when specifying -99,999.
*The number of identical pipes in parallel. 
 
<li>Open the layer '''1d_nwk_FMT_M02_Pits_001_P.shp''' in QGIS. This contains digitised points that represent the pits of the pipe network through which water can transfer to and from the overlying floodplain.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer have not been populated. Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Again, make use of the ‘Update All’ function in QGIS to update all objects at the same time:
 
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || Q
|-
| Inlet_Type || AB
|-
| Conn_1D_2D || SXL
|}
 
Note that although the same layer (1d_nwk) has been used to define the pits of the pipe network as for the culverts, different attributes have been populated. Refer to
[https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] and [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-PitsModelNetwork Table 5.24] of the TUFLOW Manual for further information on how the attributes of the 1d_nwk layer differ between nodes and channels. The attributes that we have populated for the pits, define: 
*The type of pit channel. In this case, a type ‘Q’ specifies the flow is to be defined by a depth-discharge curve from a user defined database. This database will be created in the next steps of this module.
*AB is the name of the pit inlet type referenced within the pit database.
*Specifying SXL for the ‘Conn_2D’ attribute automatically creates a 2D SX connection at the 2D cell within which the 1D pit is located. In addition, the ZC elevation of the cell will be lowered by the amount specified in the ‘US_Invert’ attribute (0.1m), and the upstream invert of the pit channel set to the lowered 2D cell elevation. This is useful to help trap the water into the pit as it flows overland in the 2D domain. 
 
<li> Open the layer '''1d_x1d_FMT_M01_nwk_001_P.shp''' created in [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial 1]]. Note that the pipe network has been digitised to outfall to the watercourse represented within the Flood Modeller Network. We will manually specify the downstream invert levels of Pipe16 and Pipe18 as the discharge point of the pipe network is above the bed level of the watercourse. Use the Info tool and click on each pipe in turn and change the ‘DS_Invert’ attribute for both pipes from -99,999 to 38m.
<li>Save both '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp'''. </li> 
'''Pit Inlet Database'''
<li>The Pit Inlet Database has been created and can be found within '''Module_data\Module_02\Pipe_Network'''. Copy the csv files '''pit_inlet_curves.csv''' and '''pit_inlet_dbase.csv''' into a new folder entitled '''pit_dbase''' within the TUFLOW folder.
<li>Open the '''pit_inlet_dbase.csv''' file. The Pit Inlet Database is similar to the Boundary Condition Database in that it references an external source file and relates this to corresponding GIS objects within the model. 
The first column contains the name of pit inlet type as referenced in the Inlet_Type attribute that was specified within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer. The second column contains the name of the source .csv file that contains the depth-discharge curve. The third and fourth columns are the heading labels of the depth and discharge columns respectively in the source .csv file. The fifth and sixth columns are the inlet’s nominated full flow area in m2 and flow width in m. [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#DD-Database-3 Section 5.11.3] of the TUFLOW Manual provides further information on the Pit Inlet Database. 
 
[[File:M07 pit inlet dbase.png]] 
 
<li>Open the '''pit_inlet_curves.csv''' file. This contains the depth-discharge curves for each pit inlet type which are referenced within the Pit Inlet Database. The curve for pit inlet type AB will be applied to all pits within this tutorial model. 

[[File:M07 depth discharge.png|800px]]

 {{Video|name= Define Pipe Network Module 02 QGIS SHP.mp4 |width=1123}} 

=Conclusion=
 1d_nwk layers have been created representing the culverts and pits that make the pipe network that of the proposed development. The layers have made use of an automated function to link the pits to the 2D domain to allow for the exchange of water between the pipe network and the floodplain. A Pit Inlet Database has been created to define a depth-discharge relationship at each pit.

 {{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Define Boundary Conditions| Back to Tutorial Module 02 Main Page]]
}}
</ol>

FM Tutorial M02 QGIS SHP Pipe Network

2025-10-07T14:41:17Z

RussellGardner:

<ol>
=Introduction=
This page describes the method for using QGIS to create the GIS based layers representing the pipe network. Two layers will be created each representing the culverts and pits. The pipe network will be connected to the 2D model domain and and a depth-discharge relationship defined at the pits via the creation of a Pit Inlet Database. 

=Method=
<li>Copy the GIS layers '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp''' within '''Module_data\Module_02\Pipe_Network''' into the '''TUFLOW\model\gis''' folder.
<li>Open the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS. This contains polylines representing the culverts that make up the pipe network.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pipes_001_L.shp''' layer have not been populated. Turn on Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Make use of the ‘'Update All'’ function as previously explained to update all objects at the same time. 

{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || C
|-
| n_or_n_F || 0.015
|-
| US_Invert || -99999
|-
| DS_Invert || -99999
|-
| Number_of || 1
|}
 
The attributes are described completely in [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] of the TUFLOW Manual. The attributes that we have populated, define: 
*The 1d_nwk type. In this case, we have specified culverts with a circular shape.
*The Manning’s n value of the culvert.
*The upstream invert level of the pipes. When -99,999 is specified, the invert level will be taken from a manually created node or pit at the upstream end of the culvert. Refer to the next steps in this module which describe where these inverts will be defined by creating pits.
*The downstream invert level of the pipes. The same rules as for the upstream invert applies when specifying -99,999.
*The number of identical pipes in parallel. 
 
<li>Open the layer '''1d_nwk_FMT_M02_Pits_001_P.shp''' in QGIS. This contains digitised points that represent the pits of the pipe network through which water can transfer to and from the overlying floodplain.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer have not been populated. Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Again, make use of the ‘Update All’ function in QGIS to update all objects at the same time:
 
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || Q
|-
| Inlet_Type || AB
|-
| Conn_1D_2D || SXL
|}
 
Note that although the same layer (1d_nwk) has been used to define the pits of the pipe network as for the culverts, different attributes have been populated. Refer to
[https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] and [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-PitsModelNetwork Table 5.24] of the TUFLOW Manual for further information on how the attributes of the 1d_nwk layer differ between nodes and channels. The attributes that we have populated for the pits, define: 
*The type of pit channel. In this case, a type ‘Q’ specifies the flow is to be defined by a depth-discharge curve from a user defined database. This database will be created in the next steps of this module.
*AB is the name of the pit inlet type referenced within the pit database.
*Specifying SXL for the ‘Conn_2D’ attribute automatically creates a 2D SX connection at the 2D cell within which the 1D pit is located. In addition, the ZC elevation of the cell will be lowered by the amount specified in the ‘US_Invert’ attribute (0.1m), and the upstream invert of the pit channel set to the lowered 2D cell elevation. This is useful to help trap the water into the pit as it flows overland in the 2D domain. 
 
<li> Open the layer '''1d_x1d_FMT_M01_nwk_001_P.shp''' created in [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial 1]]. Note that the pipe network has been digitised to outfall to the watercourse represented within the Flood Modeller Network. We will manually specify the downstream invert levels of Pipe16 and Pipe18 as the discharge point of the pipe network is above the bed level of the watercourse. Use the Info tool and click on each pipe in turn and change the ‘DS_Invert’ attribute for both pipes from -99,999 to 38m.
<li>Save both '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp'''. </li> 
'''Pit Inlet Database'''
<li>The Pit Inlet Database has been created and can be found within '''Module_data\Module_02\Pipe_Network'''. Copy the csv files '''pit_inlet_curves.csv''' and '''pit_inlet_dbase.csv''' into a new folder entitled '''pit_dbase''' within the TUFLOW folder.
<li>Open the '''pit_inlet_dbase.csv''' file. The Pit Inlet Database is similar to the Boundary Condition Database in that it references an external source file and relates this to corresponding GIS objects within the model. 
The first column contains the name of pit inlet type as referenced in the Inlet_Type attribute that was specified within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer. The second column contains the name of the source .csv file that contains the depth-discharge curve. The third and fourth columns are the heading labels of the depth and discharge columns respectively in the source .csv file. The fifth and sixth columns are the inlet’s nominated full flow area in m2 and flow width in m. [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#DD-Database-3 Section 5.11.3] of the TUFLOW Manual provides further information on the Pit Inlet Database. 
 
[[File:M07 pit inlet dbase.png]] 
 
<li>Open the '''pit_inlet_curves.csv''' file. This contains the depth-discharge curves for each pit inlet type which are referenced within the Pit Inlet Database. The curve for pit inlet type AB will be applied to all pits within this tutorial model. 

[[File:M07 depth discharge.png|800px]]

 {{Video|name= Define Pipe Network Module 02 QGIS SHP.mp4 |width=1123}} 

 =Conclusion=
1d_nwk layers have been created representing the culverts and pits that make the pipe network that of the proposed development. The layers have made use of an automated function to link the pits to the 2D domain to allow for the exchange of water between the pipe network and the floodplain. A Pit Inlet Database has been created to define a depth-discharge relationship at each pit.

 {{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Define Boundary Conditions| Back to Tutorial Module 02 Main Page]]
}}
</ol>

FM Tutorial M02 QGIS SHP Pipe Network

2025-10-07T14:40:49Z

RussellGardner: /* Conclusion */

<ol>
=Introduction=
This page describes the method for using QGIS to create the GIS based layers representing the pipe network. Two layers will be created each representing the culverts and pits. The pipe network will be connected to the 2D model domain and and a depth-discharge relationship defined at the pits via the creation of a Pit Inlet Database. 

=Method=
<li>Copy the GIS layers '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp''' within '''Module_data\Module_02\Pipe_Network''' into the '''TUFLOW\model\gis''' folder.
<li>Open the layer '''1d_nwk_FMT_M02_Pipes_001_L.shp''' in QGIS. This contains polylines representing the culverts that make up the pipe network.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pipes_001_L.shp''' layer have not been populated. Turn on Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Make use of the ‘'Update All'’ function as previously explained to update all objects at the same time. 

{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || C
|-
| n_or_n_F || 0.015
|-
| US_Invert || -99999
|-
| DS_Invert || -99999
|-
| Number_of || 1
|}
 
The attributes are described completely in [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] of the TUFLOW Manual. The attributes that we have populated, define: 
*The 1d_nwk type. In this case, we have specified culverts with a circular shape.
*The Manning’s n value of the culvert.
*The upstream invert level of the pipes. When -99,999 is specified, the invert level will be taken from a manually created node or pit at the upstream end of the culvert. Refer to the next steps in this module which describe where these inverts will be defined by creating pits.
*The downstream invert level of the pipes. The same rules as for the upstream invert applies when specifying -99,999.
*The number of identical pipes in parallel. 
 
<li>Open the layer '''1d_nwk_FMT_M02_Pits_001_P.shp''' in QGIS. This contains digitised points that represent the pits of the pipe network through which water can transfer to and from the overlying floodplain.
<li>A number of the attributes within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer have not been populated. Toggle Editing for the layer and add the following attributes to all objects leaving all other attributes unchanged. Again, make use of the ‘Update All’ function in QGIS to update all objects at the same time:
 
{| align="center" class="wikitable" width="25%"

! style="background-color:#005581; font-weight:bold; color:white;"| Attribute
! style="background-color:#005581; font-weight:bold; color:white;"| Value
|-
| Type || Q
|-
| Inlet_Type || AB
|-
| Conn_1D_2D || SXL
|}
 
Note that although the same layer (1d_nwk) has been used to define the pits of the pipe network as for the culverts, different attributes have been populated. Refer to
[https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-CulvertsAttributeDescriptions Table 5.5] and [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#tab:tab-PitsModelNetwork Table 5.24] of the TUFLOW Manual for further information on how the attributes of the 1d_nwk layer differ between nodes and channels. The attributes that we have populated for the pits, define: 
*The type of pit channel. In this case, a type ‘Q’ specifies the flow is to be defined by a depth-discharge curve from a user defined database. This database will be created in the next steps of this module.
*AB is the name of the pit inlet type referenced within the pit database.
*Specifying SXL for the ‘Conn_2D’ attribute automatically creates a 2D SX connection at the 2D cell within which the 1D pit is located. In addition, the ZC elevation of the cell will be lowered by the amount specified in the ‘US_Invert’ attribute (0.1m), and the upstream invert of the pit channel set to the lowered 2D cell elevation. This is useful to help trap the water into the pit as it flows overland in the 2D domain. 
 
<li> Open the layer '''1d_x1d_FMT_M01_nwk_001_P.shp''' created in [[Flood_Modeller_Tutorial_Module01_Provisional | Flood Modeller Tutorial 1]]. Note that the pipe network has been digitised to outfall to the watercourse represented within the Flood Modeller Network. We will manually specify the downstream invert levels of Pipe16 and Pipe18 as the discharge point of the pipe network is above the bed level of the watercourse. Use the Info tool and click on each pipe in turn and change the ‘DS_Invert’ attribute for both pipes from -99,999 to 38m.
<li>Save both '''1d_nwk_FMT_M02_Pipes_001_L.shp''' and '''1d_nwk_FMT_M02_Pits_001_P.shp'''. </li> 
'''Pit Inlet Database'''
<li>The Pit Inlet Database has been created and can be found within '''Module_data\Module_02\Pipe_Network'''. Copy the csv files '''pit_inlet_curves.csv''' and '''pit_inlet_dbase.csv''' into a new folder entitled '''pit_dbase''' within the TUFLOW folder.
<li>Open the '''pit_inlet_dbase.csv''' file. The Pit Inlet Database is similar to the Boundary Condition Database in that it references an external source file and relates this to corresponding GIS objects within the model. 
The first column contains the name of pit inlet type as referenced in the Inlet_Type attribute that was specified within the '''1d_nwk_FMT_M02_Pits_001_P.shp''' layer. The second column contains the name of the source .csv file that contains the depth-discharge curve. The third and fourth columns are the heading labels of the depth and discharge columns respectively in the source .csv file. The fifth and sixth columns are the inlet’s nominated full flow area in m2 and flow width in m. [https://docs.tuflow.com/classic-hpc/manual/2025.1/OneD-Domains-1.html#DD-Database-3 Section 5.11.3] of the TUFLOW Manual provides further information on the Pit Inlet Database. 
 
[[File:M07 pit inlet dbase.png]] 
 
<li>Open the '''pit_inlet_curves.csv''' file. This contains the depth-discharge curves for each pit inlet type which are referenced within the Pit Inlet Database. The curve for pit inlet type AB will be applied to all pits within this tutorial model. 

[[File:M07 depth discharge.png|800px]]

 {{Video|name= Define Pipe Network Module 02 QGIS SHP.mp4 |width=1123}} 

=Conclusion=
1d_nwk layers have been created representing the culverts and pits that make the pipe network that of the proposed development. The layers have made use of an automated function to link the pits to the 2D domain to allow for the exchange of water between the pipe network and the floodplain. A Pit Inlet Database has been created to define a depth-discharge relationship at each pit.

{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional#Define Boundary Conditions| Back to Tutorial Module 02 Main Page]]
}}
</ol>