I'm currently working with a DEM (10 m x 10 m resolution) that has a lot of faulty elevation values in river corridors. In order to run a hydrodynamic model I'm trying to get the following done in an autmated process (the goal is to create a Python script tool for the whole process, so I strictly want to avoid manual work on the data):
- Fill rivers in the DEM using a predefined boundary polygon for these rivers. The filling should reach from the upper edge of one bank to the other in order to only simulate the known discharges that leave the river corridors during a flood event.
So far I have used the following tools and commands to get the job done:
- Clipped the buffered river polygons from the original DEM
- Run focal statistics using 3 pixel circular search distance and the MAXIMUM values
- Run the focal statistics tool using 3 pixel circular search distance and the MEAN values three times in a row in order to even out the result from step 2
- Clipped the resulting river corridor DEM to its original extend
- Mosaiced the evend out rivers onto the original DEM
This process works fine for relatively flat areas. However there are numerous rivers in mountainous areas that have rather cliffs at one or either side of the banks. In these cases step 2 resolves in the river corridor being up way too high in the final product.
I've also tested focal statistics only using MEAN for five times in a row. This leads to partially filled river corridors, the effect is not distinct enough.
What am I missing? Any suggestions to my problem? Who has tried something similar?
(I'm using ArcGIS 10.3 on a 64bit system with an Advanced Licence)