Flood Modeller Tutorial Module02: Difference between revisions

=Introduction=

This will involve:

*Modification of the floodplain topography by the creation of a 3D TIN surface;

*Linking the pipe network to Flood Modeller; and

*The addition of an inflow into the pipe network.

=GIS and Model Inputs=

The steps necessary to modify each of the GIS inputs are demonstrated in MapInfo, ArcGIS and QGIS. At each stage please select your GIS package to view relevant instructions.

==Define Elevations (Building a TIN)==

We have provided the GIS layers necessary to modify the ground elevations to represent the proposed development. This part of the tutorial will demonstrate how a TIN is created from these GIS layers. We will also update the GIS defining the road crest level. Follow the instructions below for your preferred GIS package.

* [[FM Tute M02_ARC_Define_Elevations | ArcGIS]]

* [[FM Tute M02_MI_Define_Elevations | MapInfo]]

* [[FM Tute M02_QGIS_Define_Elevations | QGIS]]

==Define Surface Roughness==

We have provided the GIS layers necessary to modify the land use areas that will change as part of the proposed development. This part of the tutorial will require populating the layer attributes to assign Manning’s n roughness values to each land use. Follow the instructions below for your preferred GIS package.

* [[FM Tute M02_ARC_Define_Roughness | ArcGIS]]

* [[FM Tute M02_MI_Define_Roughness | MapInfo]]

* [[FM Tute M02_QGIS_Define_Roughness | QGIS]]

==Define Pipe Network==

This part of the module creates the GIS layers that make up a pipe network. The pits of the pipe network will be linked to the 2D domain. We will also create the pit inlet database which links the GIS layers to depth-discharge curves. Follow the instructions below for your preferred GIS package.

* [[FM Tute M02_MI_Pipe_Network | MapInfo]]

* [[FM Tute M02_QGIS_Pipe_Network | QGIS]]

==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 has been provided. We will also modify the existing Boundary Conditions Database to include these new inflows. Follow the instructions below for your preferred GIS package.

* [[FM Tute M02_MI_Boundary_Conditions | MapInfo]]

* [[FM Tute M02_QGIS_Boundary_Conditions | QGIS]]

===Flood Modeller 1D/1D Link===

TUFLOW models can also be configured with Flood Modeller for dynamically linked 1D pipe network 2D overland flow modelling. The main driver for this feature is for Flood Modeller - TUFLOW models to utilise the powerful pipe network and manhole modelling capabilities of TUFLOW (see Section 5.12) and be able to link these networks into a Flood Modeller river model.<br>

Flood Modeller and TUFLOW (ESTRY) nodes will be considered linked if:<br>

<ol>

<li> An "X1DQ" link means a Flood Modeller inflow/outflow is being applied at the ESTRY node (ie. Flood Modeller sends ESTRY a +/- flow and ESTRY sends back a water level). </li>

<li> An ESTRY X1DH (the default) would be used for most Flood Modeller ESTRY links. An X1DQ might be more appropriate where a Flood Modeller model stops and flows into an ESTRY model.<br>

Generally, an ESTRY timestep will be smaller than the Flood Modeller timestep. In these cases, the total volume is accumulated over all ESTRY timesteps within a Flood Modeller timestep, and applied to the Flood Modeller model as a discharge by dividing the volume by the Flood Modeller timestep.

The mass balance _MB1D.csv file includes four new columns:

*<b>X1DQ V Out</b>: The volume of water out via a X1DQ link.

The type or existence of a connection can be checked by viewing the Conn_1D_2D attribute in the 1d_nwk_N_check layer. The _messages.mif/.shp layer contains CHECK 1393 messages at each ESTRY node linked to a Flood Modeller node.

=Modify Simulation Control Files=

Now that we have made all of the necessary changes to the GIS layers, we need to update our control files to include all the changes representing the proposed development.

==TUFLOW Geometry Control File==

There have been two changes to the model that impact the TGC file:

*We have created two layers that together form a 3D TIN representing changes to the ground elevations.

*We have created two 2d_mat layers that represent changes to the land use at the location of the proposed development.

<ol>

<li>Begin by opening <b>FMT_M01_001.tgc</b> in your text editor. Save the file as <b>FMT_M02_001.tgc</b>.

:<font color="blue"><tt>Create TIN Zpts WRITE TIN </tt></font><font color="red"><tt>==</tt></font> mi\2d_ztin_FMT_M02_development_001.MIF | mi\2d_ztin_ FMT_M02_development_001.MIF </li>

The <font color="blue"><tt>Create TIN Zpts Write TIN </tt></font> command creates and writes an SMS .tin file to the same location as the GIS layer (in this case the TUFLOW\model\mi folder). The TIN can be viewed, checked and modified in SMS. This can then be read into the model directly using the <font color="blue"><tt>Read TIN zpts</tt></font> command for any subsequent model simulations.

Our intention for the 2d_mat layers created in this module is for them to build upon the existing commands which modify roughness. We would like for the new layers to overwrite the existing layers at the location of the proposed development. This process of layering and building up the model is a powerful tool in TUFLOW that minimises data duplication and provides a means of quality control. We need to ensure that the commands reading in our new 2d_mat layers are read in after the existing commands.

:<font color="blue"><tt>Read GIS Mat</tt></font><font color="red"><tt>==</tt></font> mi\2d_mat_FMT_M02_DEV_001.MIF

:<font color="blue"><tt>Read GIS Mat</tt></font><font color="red"><tt>==</tt></font> mi\2d_mat_FMT_M02_DEV_Buildings_001.MIF

<li>We will now add the commands to modify the topography to represent the proposed development. Add the following commands after the READ GIS Z Shape line:</li><br>