MAPPING LAND-USE PATTERNS IN A RIVER CATCHMENT USING GEOGRAPHICAL INFORMATION-SYSTEMS

The paper describes a methodology developed to compile land use maps using multiple data sources integrated using geographical information systems (GIS). A river basin is the base unit for the study, being a complete hydrological and topographical unit. The methodology developed has real applications in river basin modelling. Multi-temporal satellite imagery, from different agricultural seasons, was used to produce land-cover maps for the catchment, using knowledge-based re-classification. The drainage network, elevation and other topographic and thematic data were digitized from maps. The GIS was used to integrate these data sources and provide tools for manipulation of the data. This procedure enabled spectrally inseparable classes to be delineated and land use maps to be prepared. Various land use classes, including wastelands, and appropriate preventive measures, have been developed. The paper also envisages some future studies for catchment management policies.