I generated river networks (raster format) from a DEM and I also want to select the neighboring cells of the river networks from the original DEM, if the neighboring cells have a lower or equal elevation. Is there any way to achieve this with ArcGis 10?
In this plot, a branch of river network (the blue line) crosses cells no.2, no.5 and no.8. Let's pick no.5 as example. All the cells except 5 itself are neighboring cells of no.5. I want to filter cells that has an elevation no higher than cell no.5 from the neighboring cells. Assuming that the number on the plot denotes elevation, the cells I need would be cells no.1, no.3 and no.4.