Evaluation of groundwater quality at Shahid Dam site ‎using hydrogeochemical methods

The occurrence of droughts in the past few decades, rising global temperatures, and the exponential growth of population around the world, highlights the need for the quantitative and qualitative study of water resources. On the other hand, the construction of some structures, such as dams, increases the importance of studying the water quality at the construction site of such structures. In this study, using hydrogeochemical methods, the quality of groundwater in the construction site of Shahid Dam (located in the south of Semirom city) was evaluated. For this purpose, the correlation between the parameters was determined, the groundwater type was investigated using diagrams of Piper, Durov, and Stiff, geochemical ion ratios, ionic processes, and ion exchange reverse. The abundance of the main elements in the groundwater of the region includes TDS> HCo3> Ca> So4> Cl> Mg> Na> K. The chemical parameters of water in all cases in terms of drinking are favorable. The results show that there is a direct relationship with a high correlation (0.97) between EC and TDS, while a weak correlation was observed between other parameters. In general, it can be said that the relationship between HCo3 and EC, TDS, and other parameters has a higher correlation. The predominant type of groundwater in the study area is calcium bicarbonate and most of the samples have freshwater facies. According to the diagram (Na / Cl) vs. (EC), reverse ion exchange occurred in 11 samples, and only one sample had a dual origin of clay sediments and saline water intrusion. Based on the Ca + Mg versus HCo3 + So4 diagram, all samples show normal ion exchange.