American Journal of Water Resources. 2014, 2(3), 63-70DOI:
Abstract: Multivariate statistical techniques involving factor analysis (FA) and R-mode hierarchical cluster analysis (HCA) were performed on 30 groundwater samples from Rangampeta, Chittoor District, Andhra Pradesh, South India to extract principal processes controlling the water chemistry. The groundwater samples were analyzed for distribution of chemical elements Ca, Mg, Na, K, Si, HCO3, CO3, Cl, and SO4. It also includes pH, and electrical conductivity (EC). Gibbs diagrams were also constructed to identify the processes that are responsible in controlling the water chemistry. Factor analysis extracted for four factors consisting of F1 (with high loading factor of Cl, EC, Mg and Na), F2 (with high loading factor of K, (HCO3+CO3) and Ca), F3 (with high loading factor of pH and Si) and F4 (with high loading factor of SO4). The varifactors obtained from Factor analysis indicated that the parameters responsible for groundwater quality variations are mainly related to groundwater-rock interaction (particularly weathering of silicate minerals), agriculture and anthropogenic sources. With HC analysis the water samples have been classified into 4 clusters. Cluster I (13 wells) and cluster II (8 wells) have shown moderate salinity. However, cluster IV (4 wells) had the lowest concentrations of ions and classified as fresh water. Cluster III (5 wells) shows mid salinity between (I and II) and IV clusters. The distribution of these groundwater types and their quality has been found to be an in direct relation with the host rocks of the area. The results showed that the method was comprehensive and efficient in analyzing the dynamics of water quality.