Hi. I am having some difficulties in revealing flood channels in my study area.
The problem begins with the flow direction raster (input to flow acc.), where there is a -blue- region (picture attached) without flow direction being calculated. I don't want to exclude the area of course.
Thank you for your answer and my apologies for the late answer. The problematic blue area is a flat area, the white is the northernmost Gulf of Aqaba - Eilat that was taken out by setnull from the raster. I have downloaded and tried Arc Hydro Tools-->DEM Manipulation-->Fill SInks, Sink Prescreening, furthermore Flow Direction with sinks as well as fill.
