Geographical Information System for Groundwater Potential Zoning in a Peninsular Region of Bihar

Background: Exponential growth in population and over-exploitation has created groundwater stress situation in several regions globally. The peninsular area spread in the Bhagalpur and Khagaria districts of Bihar (India) is rich in groundwater, but decrease in groundwater level has been observed in the last decade. Methods: In this study, groundwater potential zones have been delineated using remote sensing and geographic information system (GIS) based AHP. The occurrence of groundwater in the study area is mainly affected by following factors- geomorphology, lithology, lineaments, drainage, soil, annual rainfall, slope, land use land cover and fluctuations in groundwater level. Above factors were considered as themes and were prioritized over each-other using the Analytic Hierarchy Process and merged in a GIS environment to delineate the groundwater potential zones. Result: Four different zones of groundwater potential- low, moderate, high and very high have been observed in the study area. The moderate and high groundwater potential zones cover 44% and 55%, respectively. The delineated potential zones have also been validated using the groundwater levels of the pre- and post-monsoon seasons, which match well. The areas at higher elevations were in the moderate potential zones.