I have a raster DEM file that I need to characterize in terms of its roughness - flat, hilly, very hilly, etc. By searching I have come across Terrain Roughness Index and Terrain Ruggedness Index. I am not sure how to make use of that information in my application. As I understand, the Terrain Roughness Index and such other indices describe the terrain characteristics at a point, however I need to grasp the terrain roughness characteristics as a whole. I may be a bit vague while asking this question, but is there such a technique or methodology available that can tell me that terrain is hilly or flat, etc. based on the elevation criteria, or any other parameter of the terrain? Thank you in advance.
