Geomorphology, hydrogeology and the study of factors affecting to karst development in Garin area, west of Iran

The study area is located in the Trusted Zagros and is placed at the border area of Hamedan and Lorestan provinces. The main aim of this research is the assessment of karst development and its potential from geomorphology and hydrogeology point of view. Highly tectonization and distribution of dissolvable carbonaceous rocks is caused to develop karstification phenomenon in this area. Some of karstic geomorphologic features such as dolin, karren, cave and karst springs (for example Gamasiab spring) are formed. In order to evaluate the hydro chemical conditions of the area, the data from 26 springs were used. The results of data analysis show that the types of water in most of the springs are calcium and magnesium bicarbonate (Ca-Mg-Hco3) which is matched with the type of karstic aquifers. Assessment of the saturation indices of calcite and dolomite show that the most part of this area is under saturated by these two minerals. This means that the ground water doesnt travel in long distances. According to the results of dye tracing test, the mean velocity of groundwater is the same as velocity in karstic areas and shows the dominancy of conduit flow regime.