In MIKE SHE, the topography defines the upper boundary of the model. The topography is used as the top elevation of both the UZ model and the SZ model. The topography also defines the drainage surface for overland flow.
Many of the elevation parameters can be defined relative to the topography by means of a checkbox in the dialogue, including
· Initial Potential Head (V1 p. 318), and
Depth parameters, such as ET Surface Depth (V1 p. 296), are also measured from the topography.
File Formats
Topography is defined from a digital elevation model (DEM) using either a dfs2 grid file, a point theme shape (GIS) file, or an ASCII XYZ file.
Non-dfs2 files or dfs2 files that have a different grid definition than the model grid are all interpolated to the grid defined in the Model Domain and Grid.
The Bilinear Interpolation (V1 p. 161) method is useful for interpolating previously gridded DEM data. Whereas, the Triangular Interpolation (V1 p. 164) method is useful for contour data digitized from a DEM. Inverse Distance Interpolation (V1 p. 165) is usually used for sparse or irregularly spaced data.
ArcGIS Grid Files If you have an ArcGIS Grid DEM, this can be converted to a dfs2 file using the MIKE Zero Toolbox. For more information see the Using MIKE SHE with ArcGIS (V1 p. 151) section. Alternatively, a dfs2 plug-in is available for ArcGIS, that allows you to read and write dfs2 files directly in ArcGIS.
Surfer Grid Files Surfer Grid files can be saved as an ASCII XYZ file and then interpolated in MIKE SHE.
Other DEM formats Most other DEM formats can be converted to either an ArcGIS Grid file or an ASCII XYZ file. If you have special requirements or difficulty, please contact your local support office.