Assessment of Groundwater Quality and Geochemical Characteristics in the Desertic Zone of Banaskantha Region of Western India

Banaskantha's desert region, especially the talukas of Vav and Suigam, faces severe water scarcity and relies heavily on groundwater. This paper provides a detailed analysis of 59 groundwater samples to assess water quality, understand geochemical evolution, and identify the main factors influencing ionic composition and salinity. In addition to water quality indicators like the Weighted Arithmetic Water Quality Index (WAWQI) and irrigation suitability indices (SAR, RSC, PI, KR, PS), various physico-chemical parameters such as pH, EC, TDS, major cations, and anions were examined. Graphical tools like Piper, Durov, and Gibbs diagrams were used to categorize water types and determine key geochemical processes. The analysis shows that the most common water types are Na–Cl⁻ and Ca–Mg–Cl, with ion exchange and evaporation playing major roles in groundwater chemistry. Correlation analysis revealed meaningful ion relationships, including an inverse link between calcium/hardness and chloride, indicating active cation exchange mechanisms. Principal Component Analysis (PCA) identified six components that explained 68.27% of the total variance, highlighting processes such as mineral weathering, salinity increase, carbonate equilibria, and local anthropogenic impacts. Hierarchical Cluster Analysis (HCA) grouped samples based on chemical similarities, supporting these findings. This comprehensive hydrochemical assessment offers valuable insights into the spatial variation and drivers of groundwater quality in this arid region. It also provides a scientific foundation for designing tailored groundwater management strategies to ensure sustainable use in a highly water-stressed environment.