Hydrogeochemical Assessment of Groundwater Quality: Seyedan-Farooq Aquifer, Fars Province

In this study, to investigate the hydrogeochemical characteristics of groundwater of Seydan-Farooq plain, chemical analysis results of twelve wells in 2016 were used. According to the spatial distribution maps of chemical parameters, groundwater quality diminishes from North-West to South-East. The study of geological formations shows that groundwater quality is suitable in the vicinity of recharging formations of aquifer which are mainly carbonate rocks and it decreases towards the outlet of the plain and next to Kajdomi Formations as well as clay-marl sediments. Stiff diagram shows that the predominant water type in aquifer is calcic-bicarbonate. However, in some wells such as wells no. 4 and 6, chlorine anion is predominant. Piper diagram of Seydan-Farooq plain indicates that five hydrogeochemical facies with predominant bicarbonate and calcium constituents. Gibbs diagram reveals that rock-water interaction process is the main source of ions and change in chemical quality of groundwater in the studied plain. Also, geochemical ion ratios were used to determine the source of salts and ions in the aquifer. Geochemical diagrams confirm that the rock-water interaction is an active process in the studied aquifer also shows that the dissolution of clay-marl sediments, ion exchange process and in some area human activities affect the groundwater quality in Seydan-Farooq plain. Since there is no linear pattern in any of the scatter plots and the samples are distributed in two areas, it can be concluded that there are at least two aquifer recharge sources.