GIS-based multi-criteria approach to delineate groundwater prospect zone and its sensitivity analysis

This study was aimed at delineating groundwater potential zones (GWPZ) using geo-spatial techniques for Ranchi district, Jharkhand (India). Data including Cartosat-1 digital elevation model (DEM), Landsat 8 satellite images, lithology, geology, soil, and water yield data were utilised in this study. The relative importance of multiple parameters including lithology, soil, slope, geology, rainfall, drainage density, and land use/land cover (LULC) that influence the availability of groundwater was determined subjectively. Analytical hierarchy process (AHP) along with pair-wise comparison decision theory was utilized to calculate the weights for each aforementioned parameter. The delineated GWPZ were categorized into four classes viz., very good zone (31.57%), good zone (45.43%), moderate zone (13.09%), and poor zone (8.53%). The sensitivity analysis indicated lithology and soil type as the most and least sensitive parameters, respectively influencing the presence of groundwater in the study area. Comparison between well discharge data and delineated GWPZ yielded a coefficient of determination (R-2) of 0.59. This study contributes to identifying priority areas where appropriate water conservation programs as well as strategies for sustainable groundwater development can be implemented.