Using Stable Isotope Analysis (δD and δ18O) and Tracing Tests to Characterize the Regional Hydrogeological Characteristics of Kazeroon County, Iran

Unpredictable climate changes are affecting water resources, especially in karst arid and semiarid areas. In such locations, the need for additional sources of water always arises. The paper gives insight into hydrogeological characteristics of Kazeroo County and resolves some unknowns around the catchment area of the springs important for water supply of the wider urban area of the city of Kazeroon, Iran, by using stable isotope analysis (δD and δ18O) and tracer test. Multiple tracer test and stable isotope analysis were conducted for research purposes. The uranine injected at Tale Milek 1 borehole was detected in the Chenar Shahijan spring in less than 2 and in the Seyed Hossein spring after 6 days. Small amounts of uranine were detected in the Sasan and Pirsabz springs. Based on the high apparent flow velocity (approximately 1750–2000 m/day), the underground system has a quick response to the precipitation during dry seasons. The assumed hydraulic connection between Shahneshin North (Asmari) and Dashtak Northzones has been confirmed by tracer test since the dye injected in Northern Asmari Shahneshin anticline appeared in the springs in Dashtak North zone. The results of water stable isotope measurements show that the catchment area of karst springs in the vicinity of Kazeroo is probably over 2000 m at the area of Shahneshin anticline and is positioned lower than the catchment area of Arjan spring.