TUFLOW SWMM Tutorial M01

Introduction

In this module, three culverts are added to represent flow through three separate road embankments. EPA SWMM is used as the solution scheme for the 1D culvert flow calculations, dynamically linked with the TUFLOW HPC 2D solution scheme.

TUFLOW SWMM Tutorial Module 1 builds from the model created in TUFLOW Tutorial Module 2 (in the TUFLOW Only tutorial dataset). The completed Module 2 model is provided in the TUFLOW_SWMM_Module_01\TUFLOW folder of the download dataset as the starting point for this tutorial. If you are not already familiar with TUFLOW, we recommend first completing Module 1 and 2 of the "TUFLOW Only" Tutorials to establish an understanding of 2D modelling, before progressing to learning how to link 1D EPA SWMM to 2D TUFLOW.

QGIS Project Initialization

QGIS Version 3.34 or newer, and QGIS TUFLOW Plugin 3.9.0.49 or newer are required to access the SWMM Processing Tools described in the following sections. For installation, see Installation of TUFLOW Plugin.
Define the Coordinate Reference System (CRS), also called ‘Projection’, for the QGIS workspace:

1. Open QGIS.
2. Go to Project > Properties…
3. In the CRS tab, type ‘WGS 84 / UTM Zone 60S’.
4. Select the matching projection in the 'Predefined Coordinate Reference Systems' section.
5. Click ‘Apply’ and ‘OK’.
6. Ensure that the projection is set correctly by viewing the bottom right hand corner of the workspace. It should read ‘EPSG:32760’.

Load in the project GIS layers:

1. Click on the ‘Load TUFLOW Layers from TCF’ symbol from the TUFLOW Plugin toolbar.
   
   
   
2. In File Explorer, navigate to the TUFLOW_SWMM_Module_01\TUFLOW\runs folder and select M02_5m_001.tcf.
3. Click ‘Open’ and ‘OK’.

Style the TUFLOW layers as preferred. Common steps to do this are:

1. Click on the ‘Apply TUFLOW Styles to Open Layers’ symbol from the TUFLOW Plugin toolbar.
   
   
   
2. Change the symbology of the DEM:
   • Right click on the DEM file in the Layers panel and select 'Properties'.
   • From the Symbology tab, under 'Band Rendering' select the following options:

   • Render type: Singleband pseudocolor
   • Color ramp: Spectral
   • Color ramp: Invert Color Ramp
   • Mode: Equal Interval

   • From the Transparency tab, set the Global Opacity to 75%.
   • Click 'Apply' and 'OK'.
   
   
   
   
3. Create a hillshade of the DEM:
   • Right click on the DEM file in the Layers panel and select 'Duplicate Layer'.
   • Right click on the DEM_copy and select 'Rename Layer'. Rename the layer to DEM_Hillshade.
   • Right click on the DEM_Hillshade file and select 'Properties'.
   • From the Symbology tab, under 'Band Rendering' select the following options:

   • Render type: Hillshade
   • Z Factor: 3

   • From the Transparency tab, set the Global Opacity to 35%.
   • Click 'Apply' and 'OK'.
   
   
   
   

SWMM Inputs and 1D/2D Linking

Create SWMM GeoPackage Spatial Database

Create a new folder in the TUFLOW_SWMM_Module_01\TUFLOW\model folder called swmm. This is the location where all SWMM inputs will be saved.

In QGIS, create the SWMM GeoPackage Database:

1. Go to Processing > Toolbox from the top drop menu options to open the Processing Toolbox panel.
2. Go to TUFLOW > SWMM in the processing tool list and select 'GeoPackage - Create'. This opens the dialog shown below.

   • To set the ‘CRS for GeoPackage’: Click the drop down menu and select ‘Project CRS: EPSG:32760 - WGS 84 / UTM zone 60S’.
   • To set the ‘Initial SWMM Sections’: Click the …, and tick on: Title, Options, Nodes--Junctions, Nodes--Outfalls, Links--Conduits, Streets, Inlets and Report.
   • To define the ‘GPKG filename to create’: Click the …, select ‘Save to File’. Navigate to the TUFLOW\model\swmm folder and save the GeoPackage Database as TS01_001.gpkg.

3. Click ‘Run’.
4. Once to tool has finished, click ‘Close’.
5. In File Explorer, navigate to the TUFLOW\model\swmm folder and drag and drop TS01_001.gpkg into QGIS.
6. When prompted by QGIS, select Links--Conduits, Nodes--Junctions, Nodes--Outfalls and Options (hold Ctrl to select multiple layers). Click ‘Add Layers’.

GIS Data Entry

A GeoPackage called SWMM_Culverts.gpkg is provided in the TUFLOW_SWMM_Module_01\Tutorial_Data folder. It contains three layers:

• Conduits: defines the culvert location, type and geometry.
• Junctions: defines the upstream culverts inverts.
• Outfalls: defines the downstream culvert inverts.

To populate the GeoPackage created in the previous section:

1. In Windows Explorer, navigate to the TUFLOW_SWMM_Module_01\Tutorial_Data folder. Drag and drop the SWMM_Culverts.gpkg into QGIS. By default, all items in the GeoPackage will be selected. Click 'Add Layers'.
2. In the QGIS Layers Panel, right click on the Conduits layer and select 'Zoom to Layer'.
3. Use the 'Select Features' tool to highlight all items included in Conduits.
4. Select 'Edit' from the top QGIS tab and 'Copy Features' from the drop down manu.
5. Select the Links--Conduits layer in the Layers Panel by left clicking on it once.
6. Make the Links--Conduits layer editable by clicking the 'Toggle Editing' symbol .
7. Select 'Edit' from the top QGIS tab and click 'Paste Features' from the drop down menu.
8. Toggle the editing off to save the edits.
   
   

   
   

9. Copy the objects from Junctions into Nodes--Junctions. Junctions are considered inlets, and should be defined at the upstream end of culverts.
10. Copy the objects from Outfalls into Nodes--Outfalls. Outfalls are treated as outlets, and are required at the downstream end of culverts.
11. Close SWMM_Culverts.gpkg
    
    

    
    

12. Inspect the attribute information within the respective layers to familiarize yourself with the data.
    
    

GIS Data Updates

The provided GIS data requires numerous updates, prior to our model simulation. We have built these updates into this tutorial to demonstrate some of the available TUFLOW SWMM model built processing tools.

The following updates are being made to Objects and Layers within TS01_001.gpkg

Update Conduit Details

Step 1 involves updating the From Node and To Node attribute information in Links--Conduits. This information is necessary to "build" the 1D SWMM network. It defines the Link/Node connections. The information we will be adding to Links--Conduits is extracted from Nodes--Junctions and Nodes--Outfalls automatically using the Conduits - Assign Node Fields tool from the Processing Toolbox.

1. In the QGIS Layers Panel, select (left click) Links--Conduits and toggle on editing.
2. From the Processing Toolbox, select the 'Editing in place' tool []. This allows the editing of an existing Layer, instead of the creation of a new Layer.
3. Go to TUFLOW > SWMM in the processing tool list and select 'Conduits - Assign Node Fields'. This opens the dialog shown below.
4. Tick on the SWMM Node Layers: Nodes--Junctions and Nodes--Outfalls.
5. Select 'Modify All Features'.
6. Once the tool has finished, click 'Close'.
7. View the attributes associated within Links--Conduits to verify the data processing has been completed correctly. The From Node and To Node attribute information is now configured correctly.
   Tip: If you wish to only update select objects during a future modelling project, instead of the entire Link--Conduits dataset, select the target objects first using the Feature by Area tool. The Conduits - Assign Node Fields tool will provide an option to Modify Selected Features, instead of Modify All Features.
   
   

   
   

Update Losses

Step 2, update the loss attributes in the Links-Conduits Layer. These values will be entered manually in this example using default values. Variation to the default values can be used in project models to reflect site specific information if desired.

1. Select (Left mouse click) Links--Conduits in the QGIS Layers panel and Toggle Editing on.
2. Right mouse click Links--Conduits in the QGIS Layers panel and select Open Attribute Table.
3. Set:
   • losses_Kentry = 0.5
   • losses_kexit = 1.0
   • losses_Kavg = 0.0
4. Save Links--Conduits

An urban pipe network is added to the model in TUFLOW SWMM Module 2. In that situation, different loss attributes are required for the road culverts and underground stormwater pipe network links. To simplify the loss attibute update step in that situation, we will be introducing the Conduits - Assign Node Fields processing tool. It is however, not necessary for this Module 1 tutorial because all the 1D SWMM inputs are embankment culverts.

Create 1D/2D Connections

The following instructions introduce a new tool that automates the creation of 1D/2D connections. For 1D SWMM, HX lines are required from the upstream end of the culvert, and SX connections are used at the downstream end of the culvert.

1. Select (Left mouse click) Links-Conduits in the QGIS Layers panel.
2. Use the select the Feature by Area tool to select all culvert objects in Links-Conduits.
3. In the search box of the Processing Toolbox panel, type SWMM.
4. From the SWMM list, choose the BC - Create channel endpoint 1D/2D connections.
5. Select the following options:
   • Input Conduits Layer = Links Conduits
   • Offset distance = 2
   • Length of BC lines = 10
   • Output Layer= Select: Save to GeoPackage. Choose TS01_001.gpkg in the model\swmm folder and click Save. A Layer Name Window will open. Provide the following name: 2d_bc_SWMM_Connections_001_L.
     

Update Junction Details

1. Select (Left mouse click) Node--Junctions in the QGIS Layers panel and Toggle Editing on.
2. From the Processing Toolbox, select Editing in place. This allows the editing of an existing Layer, instead of the creation of a new Layer.
3. Select the Junctions - Set attributes processing tool. Select the following:
   • Input bc connections layer = 2d_bc_SWMM_Connections_001_L
   • Nodes connected to 2D without Inlets (Ysur ) = 0
   • Nodes connected to 2D without Inlets (Apond ) = 50
4. Select Modify All Features.
5. Close the Junctions - Set attributes processing tool.
6. View the attributes associated within Node--Junctions to verify the data processing has been completed correctly.

SWMM Options

1. Select the Options Layer in TS01_001.gpkg file.
2. Select Toggle Editing to enable changes to be made to the Layer.
3. Right click the Options layer in the Layers Panel and select Open Attribute Table.
4. Update the following option:
   • Start Date: 01/01/2020 (USA Date Format: MM/DD/YYY)
   • Report step: 00:05:00
5. Save and Toggle Editing off.

Export SWMM INP File

SWMM does not read TS01_001.gpkg directly as an input GIS file. SWMM requires a INP file.

1. Right click Links--Conduits in the QGIS Layers panel, and select TUFLOW >> SWMM - Export inp file.
2. Select TS01_001.gpkg as the GeoPackage Input File.
3. Set the SWMM output filename to TS01_001.inp in the TUFLOW/model/swmm folder.
4. Select "Run", then "Close" after the processing is complete.

Simulation Control Files

To differentiate the TUFLOW SWMM tutorials from the TUFLOW/ESTRY tutorials, TS will be used as the new file prefix in this series of tutorials.

1. Open M02_5m_001.tcf
2. Save a copy of M02_5m_001.tcf as TS01_5m_001.tcf in the TUFLOW_SWMM_Module_01\TUFLOW\runs folder.

TUFLOW Boundary Control File (TBC)

1. Open M01_001.tbc. If using Notepad++, right click the file referece in the TCF and select Open File.
2. Save M01_001.tbc as TS01_001.tbc in the TUFLOW_SWMM_Module_01\TUFLOW\model folder.
3. Add the following additional command lines to TS01_001.tbc:
   Spatial Database == swmm\TS01_001.gpkg
   Read GIS BC == 2d_bc_SWMM_Connections_001_L ! Links the 1D culverts to the 2D domain
   
4. Save the TBC.

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TUFLOW SWMM Control File (TSCF)

A new control file, the TUFLOW SWMM Control File (TSCF), is introduced. SWMM is a 1D hydraulic solver. All 1D SWMM files and commands are referenced in the TUFLOW SWMM Control File.

1. Create a new text file called TS01_001.tscf, saved in the TUFLOW_SWMM_Module_01\TUFLOW\model folder.
2. Add the following command lines:
   Read SWMM == swmm\TS01_001.inp ! 1D SWMM input file
   
3. Save the TSCF.
   

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TUFLOW Control File (TCF)

1. Open the TS01_5m_001.tcf in a text editor:
   Add the following line in the 'Model Inputs' section:
   SWMM Control File == ..\model\TS01_001.tscf ! Reference the SWMM (1D) Control File
   Add the following line in the 'Output Settings' section:
   NetCDF Output Start Date == 2020-01-01 00:00 ! Sets the output units for the NetCDF time variable
   
2. Make the following reference update:
   BC Control File == ..\model\TS01_001.tbc ! Reference the TUFLOW Boundary Conditions Control File
   
3. Save the TCF.

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Running the Simulation

1. Save a copy of _run_M02_HPC.bat as _run_TS01_HPC.bat in the TUFLOW_SWMM_Module_01\TUFLOW\runs folder.
2. Update the batch file to reference the TS01_5m_001.tcf :
   set exe="..\..\..\exe\2023-03-AD\TUFLOW_iSP_w64.exe"
   set run=start "TUFLOW" /wait %exe% -b
   %run% TS01_5m_001.tcf
3. Double click the batch file in Windows file explorer to run the simulation.

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If your model simulation did not run. Here is a link to some comon Tutorial Trouble Shooting advice.

Check Files and Results Output

Complete the steps outlines in the following link to review check files and simulation results from the TUFLOW SWMM model simulation:

TUFLOW SWMM Tutorial 01 Check Files
TUFLOW SWMM Tutorial 01 Results

Conclusion

• EPA SWMM Culverts were added to convey water through the structures under the three roads in the tutorial model.
• Check files were used to review the application of the boundary links.
• Results through the 1D network structures were assessed.

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