Application of Reverse Geochemical Model and Hydrogeochemical Methods to Investigate the Salinity Source of Sarvestan Aquifer

In order to investigate the groundwater quality in the study area Sarvestan Aquifer, 25 samples of groundwater have been taken in June 2016. Q mode hierarchical cluster analysis (HCA) was used to partition groundwater in the study area into hydrochemical facies. Two major water groups were identified by HCA. Groundwater samples collected from the study area were classified as recharge area water (Group 1: Ca–Cl water) in the Southern and Southeast regions. Discharge area waters were identified in the vicinity of Maharlu lake and in western and northwest parts of the study area (Group 2: Na–Cl water). Principal components analysis (PCA) with varimax rotation using the Kaiser criterion identified two principal sources of variation in the hydrochemistry. A factor 1 accounts for the salinity of the water and the second factor represent calcite dissolution from Calcareous formations located in the eastern and southeast parts of the area. Inverse modeling for major ions and the results of HCA confirmed the results obtained with PCA. The results of this study show that the integration of statistical results from hydrogeochemical data with the inverse geochemical model can help in identifying the geological factors affecting groundwater quality. this study identified important mechanisms in the composition of Group 2 waters are reverse flow from the Maharlu Lake toward the aquifer and the presence of Hormoz and Sachun formations located in the northern and northeastern parts of the study area.