Unveiling recharge sources and dominant processes for alluvial aquifers using hydrochemical and isotopic techniques

Abstract

The study deals with the hydrochemistry (EC, DO, pH, HCO3–, SO2-4, Cl−, Ca2+, Mg+, Na+, and K+) and isotopic studies (18O, 2H, and 3H) of the groundwater of the Thal Doab, between River Indus and Jhelum, to delineate the sources of recharge and quality of groundwater. The groundwater based on isotopic data is recharged by two sources: the Indus River and rainfall shown by the depleted and enriched isotopic concentrations. The tritium concentrations revealed the short residence time of shallow groundwater as compared to the deeper groundwater. Furthermore, a deep groundwater upwelling zone has also been identified. Furthermore, it was found that the groundwater evolved in response to rock–water interaction, evaporation, precipitation, land use changes, and other anthropogenic activities. The groundwater system in the Chashma area is relatively safe for consumption. Future planning for the groundwater recharge zones should be the priority areas for protection, by the government water management and public health departments.