Thanks 3dbu and Lurker, been away for the last few days so sorry that i haven't replied. I do not have any multispectral imagery available so it looks like I will need to try and extract the feature data using the pixel values of the raster mapping.
The only imagery i have is orthorectified images which won't be ideal but there I am only looking for a generalisation of the area. Does anyone know of any sources of free landsat 7 imagery or other MSI suitable for Terrrain Catergorisation for Spain, particularly the Soria district?
3dbu if have time would you mind putting a quick guide of how to use the NVDI to extract the info via classification. Its been a number of years since i last did one! I am using ERDAS imagine 9.3 but have access to 2011 if needed.
Cheers for all your help.