Finding Ground water Potential zones in Jharkhnad's Pakur District through the use of geospatial and multi criteria decision making techniques

Groundwater is a crucial natural resource supporting domestic, agricultural, and industrial activities in the semi-arid regions of eastern India, particularly within the Pakur district of Jharkhand. This study applies an integrated GIS and remote sensing approach to delineate groundwater potential zones and evaluate their hydrogeological significance through a multi-criteria weighted overlay model. The analysis incorporates geology, geomorphology, slope, drainage density, lineament density, soil, and rainfall parameters to generate a Groundwater Potential Index (GWPI) map in ArcGIS. The district is categorized into five potential classes: very good (32.13%), good (41.55%), moderate (19.94%), poor (4.54%), and very poor (1.82%). The Rajmahal Trap Basalt, covering a major portion of the area, demonstrates high groundwater potential due to fracturing, vesicular weathering, and secondary porosity development. Geomorphological units such as valley fills (31.07%) and buried pediments (53.41%) act as significant recharge zones, while residual and structural hills (15.5%) promote runoff. Gentle slopes (0°–5°) and low drainage densities (0–96 m/km²) favor infiltration, and dominant NE–SW and NW–SE lineament orientations facilitate groundwater movement. Validation using pre and post monsoonal water level data shows a strong inverse relationship (R² = 0.984) between GWPI and seasonal fluctuation, confirming the model's accuracy. The study identifies the weathered and fractured Rajmahal Trap Basalt as the most productive aquifer system and establishes a reliable, cost effective framework for groundwater exploration and sustainable resource management in hard rock terrains.