Hydrogeeochemical properties of groundwater resources in Eskil plain

In this study Hydrogeological and hydrochemical characteristics of underground water resources in Eskil (Aksaray) plain were investigated. The study area is located in the south of Lake Tuz. Within the scope of the research, the geological, tectonic and stratigraphic features of the region were also examined. The Central Anatolian Crystalline Complex rock unit is located on the base of the study area. The most important units that created the aquifers in the study area are marbles belonging to Central Anatolia Metamorphites of Palaeozoic age. Faulted, fractured, and karstic-hollowed sections, which developed vertically in this unit created a high permeability in terms of hydrogeology. Although the Central Anatolia Granitoids of the Upper Cretaceous period are impermeable, they became fragile due to alterations. These units are permeable in the faulted and fractured upper belts and forms weak aquifer systems in the region. The Quaternary aged conglomerate and sandstone layers have permeable properties. In order to investigate the hydrogeochemical properties of groundwater, sampling studies were carried out from 15 different water wells in October 2015 and April 2023. The physical and chemical parameter values of groundwater in the study area vary between pH 6,8 – 8,18, electrical conductivity (EC) 717.92 – 1831 µS/cm, total dissolved solids (TDSM) 604 – 1553,8 mg/L, respectively. Groundwaters have Na-Cl, Na-HCO3, Ca-HCO3, Mg-HCO3 and Ca-Cl type water facies. Analysis results showed that depending on the distance from the LT, the water type of groundwater change from NaCl to NaHCO3 and CaHCO3 facies. Different types of water facies have developed in the region as a result of the mixing of NaCl and CaHCO3 type waters at different rates. Agricultural activities in the study area should be kept under control in terms of pollution and water use.