Flood Modeller Tutorial Module01: Difference between revisions

1D-2D linked models are able to utilise the individual benefits of 1D and 2D solution schemes. In this example, the 1D Flood Modeller scheme is used to represent the watercourses where the flow is essentially uni-directional. A 2D scheme is suited to the representation of floodplains where more complex flow patterns may occur. <br>

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[[file:Poor_2d_rep.png|400px]]<br>

Using a cell size that is coarse relative to the width of the watercourse channel may reduce the accuracy of the conveyance in the channel. There are two options for improving the representation of the creek channel:<br>

* decrease the width of the 2D cells; and/or

* model the channel as a 1D network, dynamically linked to the 2D domain (the floodplain).

 

 

Setting up a 1D/2D model where the 1D channel cuts through the 2D domain is probably the most time-consuming type of a model to setup. However, the reduction in simulation time can be beneficial and make this a good approach. For this module, the complete Flood Modeller 1D model has been provided, to allow for progressing through the module in a relatively short period of time.<br>

 

=Existing Model Data=

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.<br>

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.<br>

*1D/2D boundary links to connect the 1D ESTRY culverts to the 2D TUFLOW domain.

 

 

==Flood Modeller==

*<b>IEF</b>: A blank folder in which to store Flood Modeller Event Files used to simulate the model.

*<b>RES</b>: A blank folder in which to write the Flood Modeller result files.

For this tutorial, the floodplain of the study area will be modelled entirely in TUFLOW.

The cross-sections in the Flood Modeller 1D model have been trimmed to the top of bank to ensure there is no double-counting of storage within the floodplain.

'''Mapinfo'''<br>

Add an extra command line after <font color="blue"><tt> Read GIS Code </tt></font><font color="red"><tt>==</tt></font>..\model\mi\2d_code_FMT_M01_001_R.MIF </li>

 

'''Other GIS'''<br>

:<font color="blue"><tt>Read GIS Code BC </tt></font> <font color="red"><tt>== </tt></font> gis\2d_bc_FMT_M01_HX_001_R.shp <font color="green"><tt> ! Deactivates the cells where the watercourse has been modelled in 1D </tt></font>

 

 

<li> Topography amendments should be added in a new section at the bottom of the TGC. These are: </li>

'''Mapinfo'''

:Put an exclamation mark before the line reading. This tells TUFLOW to treat this command line as a comment:<br>

'''Other GIS'''

:Put an exclamation mark before the line reading:<br>

<li> Update the 1D/2D boundary links at the ESTRY culverts with the new layer:</li>

'''Mapinfo'''

'''Other GIS'''

:<font color="blue"><tt>Read GIS BC</tt></font> <font color="red"><tt>== </tt></font> gis\2d_bc_M04_culverts_001_L.shp <font color="green"><tt>! This command reads in SX boundaries linking the 1D ESTRY culverts to the 2D domain</tt></font>

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

'''Mapinfo'''

'''Other GIS'''

:<font color="blue"><tt>Read GIS BC </tt></font> <font color="red"><tt>== </tt></font> gis\2d_bc_FMT_M01_HX_001_p.shp | gis\2d_bc_FMT_M01_HX_001_L.shp <font color="green"><tt>! This command reads in HX boundaries linking the 1D Flood Modeller watercourse to the 2D domain</tt></font>

<li> We need to 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: <br> </li>

'''Mapinfo'''<br>

'''Other GIS'''<br>

:<font color="blue"><tt>Read GIS X1D Nodes</tt></font> <font color="red"><tt>== </tt></font>..\model\gis\1d_x1d_FMT_M01_nodes_001_P.shp <font color="green"><tt>! GIS layer referencing node IDs from Flood Modeller </tt></font>

<li> Add commands to read in the GIS layers referencing Water Level Lines drawn along the Flood Modeller component of the model: <br> </li>

'''Mapinfo'''<br>

'''Other GIS'''<br>

:<font color="blue"><tt>Read GIS X1D Network</tt></font> <font color="red"><tt>== </tt></font>..\model\gis\1d_x1d_FMT_M01_nwk_001_L.shp <font color="green"><tt>! GIS layer representing channels to allow for the digitisation of Water Level Lines (optional)</tt></font>

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In the <b>Complete_Model\FMT_M01\Flood_Modeller\IEF</b> folder a batch file has been provided. To use the batch file in this tutorial:<br>

*Move the batch file to the <b>FMT_Tutorial\FMT_M01\Flood_Modeller\IEF</b> folder

*Open the batch file in a text editor. On the 'set FloodModeller=' line, change the path from the one provided to the full path to the ISISf32.exe file that you set up with the installation folders.

*Double click the batch file in your file explorer to run the file

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The simulation will take a few minutes depending on the hardware setup.<br>

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=Review the Results=

Modelled results can be processed, reviewed and visualised in many different packages.<br>

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