Tute M01 Inspect Zpts SAGA: Difference between revisions
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* Shapes to '''2d_zpt_M01_5m_003_P'''
* Attribute to DEM_M01
* Expression to "eq(a
Select ''Okay''.
[[File:Tute M01 Saga Select By Attribute.png|frame|none|Select by Attribute]]
<li> Navigate to the ''Data'' tab in the ''Workspace'' window. The Zpts outside of the DEM should be highlighted. To delete these, right click on the '''2d_zpt_M01_5m_003_P''' item and select ''Edit >> Delete Selected Shapes''. The map window should look like the below:</li>
[[File:Tute M01 Saga Zpt NullRemoved.png|frame|none|Map View with null Zpts Removed]]
TUFLOW requires the elevation data to be in the fourth column and the inspection has added a fifth column with the DEM values. There are two ways of overcoming this:
* Updating the fourth (elevation) attribute column to have the values of the newly created (RASTERVALU) attribute.
* Remove the elevation column, so that the RASTERVALU column becomes the fourth column.
We will demonstrate the second option, the first option will results in the same data being stored twice in the shapefile, which will mean bigger file sizes.<br>
<li>In the ''Data'' tab, right-click on the '''2d_zpt_M01_5m_003_P''' item and select ''Attributes >> Show''. This should bring up a tabular view of the data:</li>
[[File:Tute M01 Saga Zpt Attributes1.png|frame|none|2d_zpt_M01_5m_003 Attributes]]
<li>Select the ''Delete Field'' icon (highlighted above)</li>
<li>In the dialogue, check the elevation check box and select ''Okay''</li>
[[File:Tute M01 Saga Zpt DeleteField.png|frame|none|Delete Fields Dialogue]]
<br>
By deleting the Elevation field we have promoted the DEM_M01 field to the fourth position and will be used by TUFLOW. In the map window, if you select a point with the ''Action'' cursor and navigate to the ''Attributes'' tab in the ''Objects Properties'' window, the output should look like this:<br>
[[File:Tute M01 Saga Zpt Fields3.png|Attributes After Removal of Elevation Field]]
<li>In the ''Data'' tab, right click on the '''2d_zpt_M01_5m_003_P''' item and select ''Save''</li>
We have now updated the GIS layer, the next step is to modify the TUFLOW geometry control file to read the new shapefile.<br>
<li>Save the current TGC file as '''M01_5m_003.tgc'''. Comment out or delete the Write MI and Stop lines entered previously (these are no longer needed).</li>
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