AN APPROACH TO LAND-USE PLANNING IN A HILLY WATERSHED USING GEOGRAPHICAL INFORMATION-SYSTEMS

The eco-socio-economic balance of a region can be preserved by proper land-use planning, particularly in hilly watersheds where erosion caus ed by rainfall is an ever-present threat. This paper describes a metho dology developed to compile a treatment-oriented land-use planning sch eme for a hilly watershed using a geographical information system (GIS ). A remote sensing based physiographic soils map and a digital elevat ion model (DEM) are the sources of soil depth and slope steepness clas ses, respectively, and are the information databases for GIS analysis. The GIS was used to integrate these databases and provide tools for m anipulation of the data. A set of knowledge-based rules was formed fro m the classification scheme formulated by Sheng and Stennett (1975) fo r hilly watersheds, modified to allow for the local land-use patterns. These rules were used to manipulate the databases and allow the estab lishment of a sustained land-use system in the watershed with proper s oil and water conservation measures. This biological engineering schem e would be a safeguard against soil erosion and other environmental th reats. A priority sub-watersheds delineation survey conducted in the w atershed indicates significant variation in the silt yield index value s, which calls for conservation planning in earnest in cases of high a nd very high priority sub-watersheds.