Assessment of Groundwater Hydrochemistry and Irrigation Suitability Using Piper, Wilcox, and USSL Diagrams in the Sina River Basin

The present study focuses on the hydrochemical evaluation of groundwater for irrigation in the Sina River Basin using geospatial techniques. Hydrochemical analyses, supported by Piper, Wilcox, and USSL diagrams, were employed to classify groundwater types, assess irrigation suitability, and understand the geochemical evolution within the basin. The Piper diagram reveals that groundwater predominantly belongs to Ca–Mg–HCO₃ and Ca–Mg–Cl facies, indicating fresh to mixed water types influenced by lithological variation, recharge conditions, and local geochemical processes. The Wilcox plot shows that most groundwater samples fall within the Excellent to Good and Good to Permissible categories, suggesting that the water is generally suitable for irrigation, although a few locations such as Jamkhed, Mehekari, and Pargoanma exhibit Doubtful to Unsuitable quality due to elevated salinity and sodium concentrations. The USSL classification identifies groundwater mainly within C2–S1 and C3–S1 classes, signifying moderate salinity and low sodium hazard, which are acceptable for irrigation under proper management and drainage conditions. Spatial analysis using GIS highlights that high-salinity zones are primarily concentrated in downstream regions, likely resulting from evaporation effects and prolonged agricultural return flow. Overall, the study concludes that while groundwater in most parts of the Sina River Basin is suitable for irrigation, regular monitoring and soil management practices are essential to sustain water quality and ensure long-term agricultural productivity.