Investigation Resistance of Sediment Particle to Erosion in Saraskanchai River by use of Mathematical Methods

In addition to Erodibility of sediment particles in river increase river sediment load، they are important factors in morphological changes. In the rivers that erodibility is high، trend of morphological changes are intensive that in this case، river is unstable. On the contrary، it will lead stability and low changes of the river. Study area of this research is Saraskanchay that has been located in the Hashtrood. The aim of this paper is investigation resistance of sediment particle to erosion by analysis of the river sediments characteristics. For this purpose، Sampling performed from studied Course and then Erodibility calculated by Bed Shear Stress and the Relative Strength Index. Grain size sediments indicated that is not significant correlation between Grain diameters of sedimentary. Cause of this is Human factors in the natural composition of the sediment grain diameter. Results indicated the critical shear stress is more from total shear stress in most parts of the river. This is indicator of Resistance of deposited particles on the river bed rather than erosion. Therefore، the river is stability and its changes are low in future.