Hydrochemical Evolution in Stressed Aquifers: Role of Groundwater Extraction, Recharge, and Lateral Flow Systems in India

In the last few decades, intensive groundwater extraction for irrigation in India has severely depleted aquifers, with growing concerns over groundwater quality. This study the first national-scale assessment linking hydrochemical evolution with extraction intensity, integrating depth-to-water levels (DTWs), groundwater recharge (GWR), and water quality parameters with the stage of groundwater extraction (SoGE) across alluvial (ALV) and hard-rock (HR) aquifers. Results show that increasing groundwater stress is associated with rising pH, declining DTWs, reduced GWR, and overall water quality deterioration, particularly within over-exploited, critical, and semi-critical (OCS) units. Within critical SoGE ranges ( 60–140