FM Tutorial M01 QGIS SHP 1D2D Links: Difference between revisions

<br>Where there are junctions within the Flood Modeller 1D model (i.e. at structures), both the nodes immediately upstream and downstream must be connected to TUFLOW. The HX lines must be broken between the junctions as this is a requirement of a linked Flood Modeller – TUFLOW model<br>.

<br>The generation of the 1D-2D links for Flood Modeller – TUFLOW models can be partially automated through the use of the TUFLOW Link Line tool in Flood Modeller Pro. Guidance on how to use this tool can be found on the Flood Modeller Pro [https://help.floodmodeller.com/docs/how-to-use-the-tuflow-link-lines-generator-tool website ].<br>

 

=Method=

To digitise the CN lines, make the <b> 2d_bc_FMT_M01_HX_001_L.shp </b> layer editable and ensure snapping has been turned on. For each node in the <b>1d_x1d_FMT_M01_nodes_001_P.shp</b> layer, draw a line from the node to the HX line. The line must snap to both the node and the HX line, so it is recommended to use the snapping tool. Draw two lines for each node, one to the left bank and one to the right bank. In the 'Type' attribute of each line, type 'CN'. Assign the digitised CN lines an ‘f' attribute’ of ‘1’. This sets the weighting to be applied in distributing the water level from the 1D node to the 2D cell.<br>

<br>{{Video|name=Define 1D 2D Bdy Links 02 SHP.mp4 |width=1123}}<br>

 

<br>The figure below shows how the nodes are connected at the confluence. Note that all Flood Modeller nodes at the junction are present within the 1d_x1D_nodes layer, and are connected to the 2D domain. The HX lines are broken around the junction. </li>

[[File:FMT 1D-2D Linking Junction QGIS.JPG|900px]]

 

 

 

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