Impact of anthropogenic and geological factors on groundwater hydrochemistry in the unconfined aquifers of Indo-Gangetic plain

Abstract

This study attempts to analyze the impact of anthropogenic activities and geological factors on the hydrogeochemical characteristics of groundwater of the Bist-Doab region of Punjab, India. Various bivariate plots, PCA, HCA, and Piper trilinear were employed to analyze hydrogeochemical processes and the association between the physicochemical parameters. The results reveal the dominance of Ca2+- Mg2+ - HCO3− type of groundwater at most of the places, attributed to the chemical weathering of carbonate and silicate minerals present in the geological setting. The process of urbanization, industrialization, over-extraction of groundwater, application of NPK fertilizers, and discharge of urban and industrial wastes were found to be responsible for altering groundwater chemistry. The bivariate plot of (SO42− + HCO3−) vs. (Ca2+ + Mg2+) reveals that both the process of ion exchange and reverse ion-exchange have contributed to the hydrochemistry of groundwater in the region. Analysis of saturation index revealed the predominance of calcite and dolomite minerals in characterizing groundwater in an unconfined aquifer setting in the area. The findings conclude that although geogenic factors attribute hydro-chemical characteristics to the groundwater; anthropogenic activities accelerate the pace of rock-water interaction in the aquifer environment. Controlling rapidly growing region-centric developmental activities may act as a boon for the conservation of groundwater resources in the region. © 2022 Elsevier Ltd