I am working with dem images for morphometric analysis. I am using topotoolbox for Ksn calculation. In my study area there is several dams in a single river and when I am using topotoolbox, it is taking the stream reach between two dams as the longest river stretch resulting in an erroneous result. I wan to effect of the dam from the dem for further analysis.
Depends on the software and whether you have mapped all of the dams or not. I've done something similar with culverts in order to "hydro condition" the DEM. If you have GIS software like ArcGIS or QGIS you can digitize small polygons on top of where the dam is. Then attribute those polygons with the elevation of the river below the dam. Convert the polygon to a raster with the same cell size as your original DEM. In ArcMap you can run the mosaic tool, add both the new rasters and the original DEM, and then set the preference for FIRST but making sure that the new rasters are on top in terms of the order that you enter them into the mosaic tool. The general approach can also be automated if you have a shapefile of dams and the locations are accurate.
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