I have a clipped DEM of my study area in ArcGIS Desktop 9.3 which I want to use for SWAT project set-up, but I need to mask it.
How do I go about it?
I'm new to the use of ArcGIS.
I don't want to use the extract by mask option.
It is unclear why you don't want to use the extract by mask option.
The only other way I know of is to set the mask through the environment settings: