Evaluating Hydrodynamic Behavior and Karst Development in the ‎Gareen Anticline ‎(Case Study: Alashtar and NourAbad Karstic Aquifers)‎

Studying hydrodynamic and hydro-chemical properties of springs can be an indicative of the karst development in a karst media. The aim of this study is to determine the hydrodynamic behavior of karstic aquifers and karstification degree of the Alashtar and Nourabad regions by analyzing the physicochemical properties and falling limb of springs hydrographs analysis. To achieve goals of this research, 10 main draining springs were chosen. After the survey of geomorphological, climatic, hydrodynamic, hydro chemical, physiographic properties and several field study, by using Malic and Vojtkova method, the karstification degree was determined. According to the Hydrodynamic Study, Amir, Chenareh and Honam springs and Abdolhosseini and Niaz springs have 2.5-3 degree of karstification. Also the groundwater flow sub-regimes type is the combination of two or more sub-regimes with merely laminar flow characterized by different discharge. Zaz and Ahangaran springs have 4 and 4.3 degree of karstification, respectively, and discharge hydrogram is composed of a sub-regime with turbulent flow and a sub-regime with laminar flow. Golembahri, Laghari and Teymour springs have 5.5 degree of karstification and complex discharge regime, a combination of one sub-regime with turbulent flow and two sub-regimes with laminar groundwater flow. According to the hydrochemical analysis, increasing magnesium ions (Mg), higher cation and anion, increasing in Electrical conductivity (EC) and total hardness (TH) and also lowering the ca/Mg in the Alashtar unit, indicate the presence of dolomitic karstic aquifers, small joints, more contact between water and rock and finally less evolution of karst in Alashtar.