Calculating mean altitude of watershed for each cell of DEM?

Question

I have a DEM of river basin, and I need to create a raster where the cell value will be the mean elevation of watershed of this cell. I have calculated watershed area (flow accumulation x cell area). But how to switch to mean elevation? Any ideas?

Answer 1

You can use In_weight_raster in Flow accumulation

1. Use your DEM as one, this will produce total of elevations inside cell's catchment.
2. Compute flow accumulation without weight, this will produce count of cells inside target cell's catchment.
3. Their ratio is average elevation of catchments