A rule-based soil erosion model for a hilly catchment

Abstract Catchment resources, generated from multi-source data (remotely-sensed, map- and ground-based systems), were input to a raster-based Geographical Information Systems (GIS) after geometrically co-registered to a standard grid (pixel). The GIS used was the PC-based, indigenously-developed package, called GRAM (Geo-Referenced Area Management). A set of knowledge-based rules, for assessing the soil erosion of this heterogeneous hilly catchment, were formulated from the knowledge of the multi-disciplinary resource-experts and the knowledge of the local catchment resources, in addition to the field observations. This rule-based model, which is hopefully fast and cost-effective and without effect of the individual bias, helped in inferring the erosion intensity units that most likely to occur at any given pixel in the system. Finally, the catchment was grouped into four different erosion intensity units namely very severe, severe, moderate to severe and slight to moderate. The quantitative soil loss (t ha −1 year −1 ) ranges, estimated by USLE model by a spatial information analysis approach (GIS), were also computed: (a) Very severe (>50): (b) Severe (40–50); (c) Moderate to severe (20–40); and (d) Slight to moderate (