Modifying the elevation of an area within your model can be used for specifying elevations for proposed defences, filling holes/areas of missing data in your underlying DTM, and much more.

After using the z-mod vertices tool to fill the shapefile vertices with elevation data, you can edit this further. This could include manually adjusting the elevations at individual vertices, or adjusting the method selected by the solver for the elevation modification.

Steps

Select the relevant shapefile in the Layers panel. Right-click and select Start Edit.
Note:
You need to select the shapefile of the vertices (created using the z-mod vertices tool), not the initial area shapefile drawn.
Right-click the shapefile again and select Show Attributes. This will display all the vertices in a table, with all the new data (taken from the grid(s) you provided within the z-mod vertices tool).
Edit individual entries with the attributes table by selecting the entry and typing a new value.
Note:
The default elevation modification method will be to use the elevations provided in the height column. You can adjust this method by adding a new attribute column.
To do this, click Edit attribute table fields (3rd button from right in toolbar). The Field Editor tool will open. In the top right of the tool, create a new attribute of Type “text”, and Name “method”. Click the Add new field at end button, and close the Field Editor tool.
In the newly created 'method' column, use the drop-down to select from the following elevation modification options.
- Set (or blank, the default) - the elevation used is the height provided, and overrides the value (if present) in the DTM
- Add - the elevation used is the height provided added to the elevation in the DTM (Note that the height can be negative)
- Min - the elevation used is the minimum of the two values; the height provided and the elevation in the DTM
- Max - the elevation used is the maximum of the two values; the height provided and the elevation in the DTM
When you have completed your edits, in the Layer Editor tab, click Save and Stop Edit.