The chemical evolution of groundwater in the Kerman plain aquifer, Iran

Abstract

A comprehensive hydrogeochemical study was carried out in the Kerman Plain Aquifer, Iran. Groundwater samples were collected from 58 sites. Groundwater was analysed for major constituents (Na+, K+, Ca2+, Mg2+, Cl–, SO42– HCO3–. Different methods including composite diagrams, saturation indices and multivariate statistical methods were employed in assessing groundwater quality. The results show that the main hydrochemical facies of the aquifer (Na+, K+– Cl– SO42–) represents 73% of the total wells. Calcite, dolomite, and gypsum solubilities were assessed in terms of the saturation index indicating supersaturation with respect to calcite and dolomite and undersaturation with respect to gypsum. Groundwater samples were classified into three distinctive groups using cluster analysis. The results of factor analysis indicate that four factors explain about 88.9% of the total sample variance. The variables underlying the first and the most important factor are mainly controlled by halite dissolution. Dissolution of gypsum is the second important source of salinity.