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FM Tutorial M02 QGIS GPKG Define Elevations: Difference between revisions

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Created page with "=Introduction= This page describes the method for using QGIS to create a 3D TIN, modifying the zpt elevations to represent the proposed development. Refer to the <u>[https://..."
 
 
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=Method=
<ol>
<li>CopyOpen the contents of the <b>FMT_Tutorial\Module_data\Module_02\2D_Development</b> intofolder thein <b>TUFLOW\model\gis</b> folderQGIS. This folder contains the following two layers: <br>
*<b>2d_ztin_FMT_M02_development_001_R.shp</b>, and
*<b>2d_ztin_FMT_M02_development_001_P.shp</b>
<li>DragMove andthe droplayers the'''2d_ztin_ layerFMT_M02_development_001_R.shp''' and '''2d_ztin_ FMT_M02_development_001_P.shp''' into the project GeoPackage file '''M02_5m_002.gpkg''' in the Browser Panel. ▼
 
<li>Close the two layers in the Layers Panel and then reload them from the project GeoPackage file '''M02_5m_002.gpkg'''.
<li>Open the layerThe '''2d_ztin_ FMT_M02_development_001_R.shp''' withinlayer QGISconsists andof observe thea polygon and its attributes. This polygonwhich defines the area within which we wish to alter the zpt elevations. Any points falling within the polygon are used for creating the TIN surface. The attributes of this polygon have been left blank (are set to 0) as the elevations will be defined in a separate layer.
<li>Drag and drop the layer '''2d_ztin_ FMT_M02_development_001_R.shp''' into the project GeoPackage file '''M02_5m_002.gpkg''' in the Browser Panel.
<li>Open the attribute table for the layer '''2d_ztin_ FMT_M02_development_001_P.shp'''. withinAll QGIS and observeof the points and its attributes. These points all have elevations assigned to the ‘Z’ attribute and will be used when generating the TIN. Note that none of the points are snapped to the polygon within the '''2d_ztin_ FMT_M02_development_001_R''' layer. The elevations of the polygon’s perimeter will therefore be based on the current zpt values (i.e. the zpt values assigned by any prior commands). Later on in this tutorial, we will specify the command used within the tgc to associate the two GIS layers with each other.<br>
▲<li>Drag and drop the layer '''2d_ztin_ FMT_M02_development_001_P.shp''' into the project GeoPackage file '''M02_5m_002.gpkg''' in the Browser Panel.
 
<br>{{Video|name= Define Elevations Module 02 QGIS GPKG.mp4 |width=1123}}<br>
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The two 2D_tin layers will together modify the zpt elevations in the area of the proposed development. The latter part of this module will demonstrate the command used to write a .tin file to allow for viewing and editing of the TIN directly in SMS. Checks will also be carried out to observe how the TIN has been generated. Please return to the main page of the [[Flood_Modeller_Tutorial_Module02_Provisional#Define Surface Roughness|Flood Modeller Module 2 Tutorial]].
 
{{Tips Navigation
|uplink=[[Flood_Modeller_Tutorial_Module02_Provisional| Back to Tutorial Module 02 Main Page]]
}}
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