FM Tute M01 QGIS 1D2D Code: Difference between revisions

In this section we will deactivate the 2D cells where the 1D Flood Modeller component is replacing the 2D solution.<br> The width of the deactivated 2D area should be approximately equal to the width of the 1D cross-sections. This step essentially replaces the conveyance of the deactivated 2D area with an equivalent 1D conveyance.

<li>Import in an empty <b>2d_bc_empty_R.shp</b> layer from within the '''FMT_tutorial\FMT_M01\TUFLOW\model\gis\empty''' folder.</li>

<li>Save the layer as <b>2d_bc_hxi_FMT_001_R.shp</b> in the '''FMT_tutorial\FMT_M01\TUFLOW\model\gis''' folder. </li>

<li>Open the <b>Inactive_area.shp</b> GIS layer from '''Module_Data\Module_01\shp''' folder. Select all objects from within this layer, copy and paste into <b>2d_bc_hxi_FMT_001_R.shp</b>. </li>

<li> For all polygons assign a 'type' attribute of 'CD'. A 2D BC type of 'CD'This designates the digitised polygon as a code polygon. Thewhere codethe polygon2D definescells ifwithin theit 2Dmay cellsbe areeither active or inactive. </li>

[[File:FMT QGIS 1D2D Code attribute.JPG|800px700px]]

<li> Observe how the code polygon has been digitised between nodes FC01.35 and FC01.34. The polygon covers the area between these two Flood Modeller nodes. This is because overtopping of the embankment at this location has been represented in the 1D Flood Modeller component of the model.</li>

[[File:FMT QGIS 1D2D Code Polygon Digitisation.JPG|500px400px]]

<li> Observe how the code polygon has been digitised downstream of node FC01.11. In this case, no code polygon has been defineddigitised over the embankment. This is because overtopping of the embankment will be modelled in the 2D TUFLOW component of the model. ThisThe is'''2d_bc_FMT_M01_HX_001_L.shp''' layer whycreated therepreviously arecontains additional HX boundary polylines at the upstream and downstream faces of the embankment to allow for overtopping.</li>

[[File:FMT QGIS 1D2D Code Bank Digitasation.JPG|600px400px]]