Evaluation of Erodibility of Formations in the Khangah-Sorkh Watershed (Urmia) Using a Rain Simulator

Erosion is one of the major causes of waste of water and soil. Perhaps the main reason for failure to control erosion is the weakness of knowledge and recognition of this phenomenon. Due to the great value of soil and the subsequent problems arising from the movement of its constituents, the erosion problem must be understood and controlled. Therefore, one needs to determine the susceptibility of geologic formations to erosion, in order to determine its mitigation. This research has been carried out in order to investigate the erodibility potential of the Khanghah-Sorkh (Urmia) watershed using the BSTF rainfall simulator. The simulation was performed at two intensities of 40 and 50 mm/hr on two slopes of 0-13 and 13-25% on each geologic formation. The results showed that the highest and lowest sediments were collected from OML</sup> (the calcic-reefy of Qom) (107.4 g) and the CM Formation (tectonic mix) (4 g). Thus, the OML</sup> formation which contains marl layers, is more susceptible to erosion and produce a larger amount of sediment relative to that of the CM formation which highly resistant to erosion. Therefore, it yields a larger amount of sediment.