A Statistical Approach to Study the Evolution of Groundwater of Vishwamitri River Basin (VRB), Gujarat

Abstract

Groundwater is the most vulnerable, exploited natural resource which is a key source of freshwater in the world. Its regular decline in both quality and quantity are an important concern of research. The focus of the present study is to understand the important hydrogeochemical processes involved in the groundwater evolution of Vishwamitri River Basin (VRB), Gujarat, India, using Principal Component Analysis (PCA) technique. To achieve a symmetrical data distribution, log-transformation was applied in this study. This statistical approach decreases the data outlier. A Shapiro-Wilk statistic was employed to test the normal distribution of the data set. The results revealed that ten elements (TDS, bicarbonate, chloride, sulfate, sodium, calcium, magnesium, fluoride, iron and strontium) showed normal distribution. The PCA of 60 groundwater samples using 10 normally distributed chemical parameters indicates that the dominant geochemical process is rock-water interaction through dissolution and cation exchange reactions within the VRB aquifers. This study also reveals that, due to over use of chemical and fertilizers, the sulfate loading is high in groundwater. Therefore, the combined process of natural rock-water interaction, weathering and anthropogenic activities play a significant role in controlling the chemical composition of groundwater of VRB.

Geochemical variations due to salinization in groundwater along the southeast coast of India

“…The seawater intrusion (SWI) in the coastal region not only renders the quality of groundwater non-potable but also affects the vegetation, soil conditions and the sustainability of groundwater [21]. The mixing of seawater and freshwater in coastal aquifers leads to the lateral migration of sea water into the aquifer affecting the groundwater chemistry.…”