DEM statistics

Discussion created by annieb48 on May 8, 2011
Latest reply on May 11, 2011 by timothy_hales-esristaff

I am fairly new to using ArcGIS (GIS software in general, actually!) and I am trying to generate info for some points (sample locations) using a DEM. I've tried to figure out how to do this using the manual but am a bit overwhelmed & unsure about the correct methods!

Using the DEM, I hope to determine the slope, upslope contributing area and topographic wetness index for each of my sample locations. At present, my sample points are a separate layer to my DEM.

Do I need to merge or overlay these points to the DEM before I can calculate slope, UCA and TWI? If so, how is this done?

I have not delineated the boundary of the catchment I am working in, and my DEM extends beyond the catchment boundary. I have the catchment boundary in a separate layer - is it possible to clip the DEM using this boundary layer?

Is Spatial Analyst the correct extension to carry out these processes?

I know this is a lot of questions, but if anyone can help me with just one of them, that would be great!

Thanks for your help,