Digital Elevation Models as Data Source for Land Suitability Analysis in Colombia

Land unit definition and its characterization are basic tasks in the land suitability analysis. Until recently manual methods were used for delineating land units and suitability analysis was done mainly in a qualitative way. The availability of DEMs and the GIS capabilities make feasible to apply a more quantitative approach. The purpose of this study was to evaluate the capabilities of Digital Elevation Model GIS to determine several terrain parameters that can be useful in the land suitability analysis and integrate them in a suitability model. A DEM from Terra-ASTER data and a one from SRTM were used to calculate curvature, slope, aspect, wetness index, relief index solar radiation. Results for key parameters were compared with those of traditional methods and indicate that a good improvement of traditional methods can be obtained at a low cost and with appropriated confidence.