Delineation of Potential Groundwater Recharge and Productive Aquifer Zones in Delhi Area Based on 18 O Signatures and GPS

Urban Farm DB summary

Peri-urban agriculture in the Delhi-NCR area is highly dependent on groundwater availability amid rapid urbanization. This study integrates dynamic δ18O isotopic composition data on groundwater with static data such as elevation of recharge sites to delineate potential recharge zones and hydrodynamic aquifer zones. Significant δ18O-elevation relationships were found (r² = 0.808 to 0.982), with recharge-site elevation resolutions of about 20m in the northwest and 75m in the southwest, identifying potential recharge zones at elevations of 210-230m in the northwest and above 260m in the south. However, variation in groundwater isotopic composition over time indicates that the corresponding aquifers are relatively small and of low productivity, and points to the likely presence of many low-permeability zones in the northwestern recharge areas — a constraint on the groundwater resources that sustain peri-urban agriculture there.