Integrated groundwater vulnerability assessment in the Pench River Basin, Madhya Pradesh, Central India using DRASTIC-based models

Groundwater vulnerability assessment is vital for sustainable management, especially in regions with intensive agricultural and urban activities. This study evaluated groundwater susceptibility in the Pench River Basin using DRASTIC, DRASTIC-AHP, and modified DRASTIC-AHP models. Seven key hydrogeological parameters, net recharge, aquifer media, depth to water, soil media, slope, hydraulic conductivity, and vadose zone impact, were integrated, along with Land Use and Land Cover (LULC) in the modified model. Vulnerability indices ranged from 43 to 182, categorizing the area into five classes: very low (17.78%), low (21.67%), moderate (24.24%), high (19.31%), and very high (17.00%). Central and southern regions exhibited heightened vulnerability due to shallow water tables (< 3.56 mbgl) and high recharge rates (38% of the area). Urban (38%) and agricultural zones (29%) were identified as high-risk areas, while vegetation (23%) and barren land (10%) showed reduced vulnerability. Validation with 84 groundwater samples revealed fluoride concentrations (> 0.63 mg/L) strongly correlated (𝑅²=0.45) with vulnerability, demonstrating the modified DRASTIC-AHP model's superior accuracy and applicability. Findings indicate excessive fertilizer use and improper sewage disposal as major contributors to contamination, necessitating targeted interventions like regulating agricultural runoff, managing urban wastewater, and implementing artificial recharge. This study underscores the importance of integrating LULC into vulnerability assessments and highlights the need for advanced modeling to improve precision and support sustainable groundwater management.