Determining the flow regime in karst aquifers using the hydrochemistry of representative springsCase study: Saldoran, Zarab and Sokhteh anticlines in southwest Iran

Using the results of chemical analyzes of karst spring water is one of the ways to determine the type of flow system in karst aquifers. In this research, a number of representative springs in the anticlines of Salduran, Zarab and Koh Sokhte in Chaharmahal and Bakhtiari provinces, which are among the largest springs draining the karst system in this region, were selected and the results of chemical analysis of their water were used to calculate the saturation indices of calcite, dolomite and a partial pressure of carbon dioxide is used. The results show that the water of selected springs is unsaturated from calcite and dolomite and the dissolution of carbonate rocks continues. Also, the relatively low values of SID compared to SIC show that the water of the selected springs mainly passes through limestone areas and dolomite rocks are not developed much in the karst aquifer related to these springs. In addition, the low values of SIC and SID show that the residence time of water in the aquifers of the selected springs in the study area of Salduran-Zarab is relatively short, and this indicates the dominance of mixed flow (flowdiffuse-flow or flow-flow) in the aquifer. Karst has these springs.