Assessment of groundwater quality and geochemical characteristics in the desertic zone of Banaskantha region of western India

Banaskantha is a desert area that includes the Vav and Suigam talukas of northwestern Gujarat, with severe water shortage and rising salinity pressures. This paper assesses the hydrogeochemical properties, including groundwater quality, based on the analysis of 59 systematically collected samples. Physico-chemical parameters (pH, EC, TDS, major cations, and anions) were measured and the Weighted Arithmetic Water Quality Index (WAWQI) and irrigation indices (SAR, RSC, MH KR, PS, and PI). Hydrochemical facies and the leading geochemical processes were determined through the combination of graphical (Piper, Durov, Gibbs) and statistical (PCA, HCA, correlation) methods. Findings indicate that groundwater is mainly Na-Cl and Ca-Mg-Cl, resulting from evaporation, ion exchange, and halite dissolution under arid climatic conditions. More than 80% of samples had no drinking water, and almost all had high salinity levels that posed irrigation hazards. The 6 components extracted by means of PCA accounted to 68.27% of the total variance, meaning that evaporative concentration, carbonate weathering, and anthropogenic nitrate enrichment dominated. Correlation and cluster analyses showed strong associations among TDS, EC, and hardness across zones with varying salinity and nitrate contamination. This combined hydrochemical statistical evaluation offers the initial overall understanding of the evolution of the groundwater in the arid belt of Banaskantha. The results emphasize the importance of salinity reduction, regulated irrigation, and local groundwater regulation in order to achieve the sustainability of using this valuable resource.