Delineation of groundwater potential zones using remote sensing and Geographic Information Systems (GIS) in Kadaladi region, Southern India

The primary objective of this research is to delineate potential groundwater recharge zones in the Kadaladi taluk of Ramanathapuram, Tamil Nadu, India, using a combination of remote sensing and Geographic Information Systems (GIS) with the Analytical Hierarchical Process (AHP). Various factors such as geology, geomorphology, soil, drainage, density, lineament density, slope, rainfall were analyzed at a specific scale. Thematic layers were evaluated for quality and relevance using Saaty's scale, and then integrated using the weighted linear combination technique. The weights assigned to each layer and features were standardized using AHP and the Eigen vector technique, resulting in the final groundwater potential zone map. The AHP method was used to normalize the scores following the assignment of weights to each criterion or factor based on Saaty's 9-point scale. Pair-wise matrix analysis was utilized to calculate the geometric mean and normalized weight for various parameters. The groundwater recharge potential zone map was created by mathematically overlaying the normalized weighted layers. Thematic layers indicating major elements influencing groundwater occurrence and recharge were derived from satellite images. Results indicate that approximately 21.8 km² of the total area exhibits high potential for groundwater recharge. Groundwater recharge is viable in areas with moderate slopes, particularly in the central and southeastern regions.