Groundwater sustainability mapping for managed aquifer recharge in Dwarkeswar River basin: Integration of watershed modeling, multi-criteria decision analysis, and constraint mapping

Groundwater sustainability is a pressing issue in many regions, especially in semi-arid and drought-prone areas, impacting progress towards achieving the Sustainable Development Goals (SDGs). This study addresses this challenge by assessing Managed Aquifer Recharge (MAR) potential in India's Dwarkeswar River basin. The study employs a systematic approach integrating watershed modeling using the Soil and Water Assessment Tool (SWAT), multi-criteria decision analysis (MCDA), and constraint mapping techniques. Initially, the SWAT model evaluates water availability for MAR, followed by an MCDA-AHP method to identify optimal sites based on ten spatial parameters encompassing technical, economic, and environmental criteria. Furthermore, the study employs constraint mapping to refine site suitability assessments and sensitivity analysis to gauge the robustness of the results. The SWAT analysis revealed substantial variation in runoff volumes among the eight sub-basins, ranging from 8.34 m³/s to 136.28 m³/s, indicating significant availability of source water for MAR. Results from the MCDA followed by constraint mapping indicate that 51.57% of the study area is unsuitable for MAR, while 0.12%, 34.59%, and 13.72% are classified as low, moderate, and suitable zones, respectively. Sensitivity analysis reveals that geological attributes, soil thickness, runoff, and slope significantly influence the suitability scores, underscoring their impact on MAR feasibility. Validation with major pond locations confirmed the accuracy of this integrated approach in identifying suitable sites for MAR initiatives. This emphasizes the importance of holistic groundwater management strategies for sustainable water resource utilization and achieving the SDGs.