Delineation of groundwater potential zones of India using GIS based Fuzzy-AHP techniques

Abstract

India's subtropical monsoon climate, rapid population growth, urban expansion, and industrial development pose long-term challenges to sustainable groundwater management. In this study, GIS-based Fuzzy Analytical Hierarchy Process (Fuzzy-AHP) has been employed to delineate Groundwater Potential (GWP) zones of India at national and state levels. Ten hydro-meteorological and physiographic factors were used and the resulting GWP zonation indicated that high, moderate, and low GWP zones encompass 27.43 %, 42.25 %, and 30.32 % of India's territory, respectively. High GWP zones are concentrated in the Indo-Gangetic plains, coastal regions, and scattered interiors, with states such as Tripura, Bihar, Punjab, Assam, West Bengal, and Uttar Pradesh having a majority of high GWP areas. Hilly states exhibit low GWP, while regions with consolidated formations display extremely low GWP. Moderate GWP is observed in Manipur and Nagaland due to high rainfall and uneven slopes. The reliability of the GWP map was validated with precision, recall, F1-score, F2-score, and accuracy scores of 0.67, 0.75, 0.71, 0.73, and 0.78, respectively. Probabilistic performance metrics of AUC-ROC = 0.86 and AUC-PR = 0.85 supported the performance metrics scores. The AUC-SR score indicated strong spatial prioritization capability of the GWP map, as nearly 70 % of validation locations were captured within the top 50 % of the GWP zones of this study. The domain knowledge of experts and the sensitivity analysis highlighted aquifers, drainage density, and groundwater depth as the most influential factors driving India's GWP, whereas LULC contributed with the minimal impact. This study offers a decision-support tool for informed groundwater planning and sustainable water resource management.