Effects of geological formation on desertification in the Mond watershed

Geological formations are one of the most distinguished aspects of desertification, affecting the water quality of the Mond River. A number of 15 salt domes in this watershed have a significant impact on the water quality of Garagaj and Firozabad rivers, forming the main branches of the Mond River. In the current study, samplings was done in order to determine the water quality of the rivers before and after the salt domes and qualitative and quantitative statistics were collected from hydrometric stations along the river. The samples were analyzed for pH, EC, SAR, cations, and anions. Wilcox diagrams were made for each station. In addition, the measured discharges were classified into different classes by using long-term daily discharge data. Changes in water ion levels were investigated at different longitudinal intervals of river using the average values of major anion and cation concentrations, and finally the role of the study formations in degradation of water quality of the Mond River were detected. According to the obtained results, three salt domes, located in the south west of Firoozabad, were the main causes of Firoozabad River water salinity, having the greatest impact on the water quality of Mond River. In addition, the Korab River, originating from saline springs of Khorab salt dome, had considerable impact on the water quality of Firozabad River. Finally, the saline water of the Firoozabad River, entering the Mond River, was identified as the main cause of salinity.