Water is necessary for domestic, agricultural, and industrial uses, but overexploitation and climate change are putting more strain on the world's groundwater supplies, which highlights the necessity for a methodical evaluation of groundwater potential in Mettur Taluk in Tamil Nadu. Mettur Taluk is experiencing increasing groundwater stress due to semi-arid climatic conditions, rainfall fluctuations, and growing agricultural demand. Moreover, over-extraction and falling groundwater levels require a progressive assessment of the groundwater resource's potential in its management. It is still poorly understood, with few data-driven assessments to direct sustainable groundwater management. To provide a methodical, data-driven evaluation, this study uses Geographic Information Systems (GIS) and the Analytical Hierarchy Process (AHP) to identify groundwater potential zones (GWPZs) in Mettur taluk, Tamil Nadu. Thematic layers, encompassing lithology, land use and land cover, precipitation, soil characteristics, drainage density, lineament density, and slope, were compiled from various data sources and analyzed using GIS. The thematic layers were assigned due scores using the Analytical Hierarchy Process (AHP) to determine the weights of the layers, and a weighted overlay method was employed in a GIS environment to create the Groundwater Potential Zone (GWPZ) Maps. The model was validated using Receiver Operating Characteristic (ROC) analysis, yielding an Area Under Curve (AUC) value of 0.802, indicating good predictive accuracy. Four groundwater potential classifications were identified for the research area: low (6.87%, 53.36 km²), moderate (24.11%, 187.23 km²), high (55.67%, 432.28 km²), and very high (13.33%, 103.56 km²). This allocation implies that, although a significant part of the Area possesses favourable environmental conditions for groundwater occurrence, there is a need to manage and conserve it, especially in locations with moderate to low groundwater potential. This study provides a region-specific decision-support framework for sustainable groundwater management in data-scarce hard rock terrains.
Balasubramaniyan et al. (Fri,) studied this question.