Geoinformatics in groundwater potential mapping and sustainable development: a case study from southern India

Groundwater potential in a basin is controlled by the amount of precipitation, nature of infiltration, lithology, geomorphology, soil and structure. Sustainable groundwater potential mapping emphasizes not only location of the potential groundwater zones, but also the optimum utilization of resources without affecting the aquifer systems. The Uppar Odai sub-basin in the Amaravati River basin, located in southern India, was selected for sustainable groundwater potential mapping through geoinformatics. In the present case, geomorphology, subsurface layer information derived from electrical resistivity data and lineaments were integrated for sustainable groundwater potential mapping. The structure contours indicate apparent resistivity zones at different depth configurations. The data were analysed at different depth perceptions of 25, 50, 75 and 100 m depth below ground level (b.g.l.). In order to assess the overall configuration of aquifer zones, profiles were plotted across the sub-basin in different directions. The geomorphology and lineaments interpreted from IRS P6 LISS III satellite data were integrated with resistivity data for the generation of a sustainable groundwater potential map. Ranking and weight were assigned for all thematic layers based on their importance in controlling the occurrence of groundwater. The spatial integration was carried out using ArcGIS 9.3 software. The integrated map shows three different potential zones as highly favourable, moderately favourable and least favourable groundwater potential zones. The results obtained through the GIS spatial integration are validated with water level data. Based on the present groundwater draft in the sub-basin, a sustainable groundwater plan is suggested.