Delineating groundwater potential zones of agriculture dominated landscapes using GIS based AHP techniques: a case study from Uttar Dinajpur district, West Bengal

Groundwater depletion and contamination has increased in recent decades due to increased groundwater use and the intensification of agricultural practices. The increasing demand for groundwater has increased the need to identify areas in a landscape where groundwater resources are most likely to be available. The present study was conducted on three management blocks in West Bengal in India where excessive groundwater use for agriculture primarily has caused groundwater levels to decrease. An AHP technique was employed to compile a groundwater resources potential map for the study area. The map was compiled using ten thematic layers including: geomorphology, slope, geology, landuse/landcover, rainfall, slope curvature, the Modified Normalized Difference Water Index, drainage density, soil type and the Topographic Wetness Index. The groundwater potential map has been validated using the groundwater fluctuation data and correlated with agricultural dependency on groundwater. The final potential map obtained categorized the regions into five categories. These are areas with a poor, low, moderate, high and very high prospectivity.