Understanding the geochemical evolution of groundwater in Central Gujarat, India: an integrated hydrogeochemical and multivariate statistical approach

In the present study, the geochemical origin of groundwater of Viswamitri River Basin (VRB), Gujarat, is established by integrating the different types of hydrogeochemical investigations and multivariate statistical techniques. Here, both natural and anthropogenic activities induce the hydrogeo-chemical origin of groundwater. Geochemistry of groundwater is primarily regulated by the evaporation process as confirmed by Gibbs diagram. X–Y scatter plots indicate that the source of major cations in groundwater is the weathering of rock and/or soil. The SI values of hematite, dolomite, and goethite depict an oversaturated state, and therefore, the groundwater of VRB is incapable of dissolving any additional amount of that mineral. The plots of Piper trilinear diagram, expanded Durov diagram, Langelier and Ludwig diagram, box-whisker plots, and R-mode HCA reveal that the dominant facies, covering 648 sq. km of the study area, is saline water facies. The high concentration of these major ions is primarily associated with the processes like cation exchange, mineral dissolution in the aquifer system as proved by the saturation indices and Giggenbach triangle. The stable isotopic signature of the groundwater of VRB point towards evaporation as the primary process accompanied simultaneously by precipitation during the formation of groundwater. Climate change, alteration in land use, anthropogenic activities, surface water infiltration, and social evolution all have an impact on groundwater resources.