I am trying to come up with a workflow that will extract the location of surface mines from a DEM. My original thought was to fill the depressions in the DEM and then subtract the original DEM from the filled DEM to produce a grid of the sinks in the landscape. This worked well, and the surface mines stick out like a sore thumb because they are very deep sinks, but it also includes shallower natural depressions that were filled in the landscape.
Is there a way I can only fill sinks that exceed a certain depth such that when I subtract the original DEM from the filled DEM the resulting grid only includes the deepest of sinks (which will, hopefully, be all of the mines in the landscape).
I'm using ArcGIS 10 but I recently discovered SAGA GIS so any solutions using SAGA would be welcome as well.