The investigation of Bank Stability and Toe Erosion Because of Surface Flow Using BSTEM Model (Case Study: Beshar River)

The Vital need for river management is understood and predict of bank erosion processes. Almost models will not be able to evaluate bank erosion,accurately. BSTEM model is the most usable model in many of river engineering projects in the world. Necessary data for this model are related to driving and resisting forces controlled by hydraulic and Geotechnical processes. These data include geometry, hydraulic and Geotechnical data that using of sampling, field measurements and laboratory test obtained. The results of this study showed that the regions with cover vegetation in comparison to theregion of cover vegetation without significant differences in sustainability observed. Safety factor in the regions without cover vegetation is less than 1 that river in this section is instable Among the region of without cover vegetation only section 3 (event 4) have shown a safety factor less than 1. Compare the sections of viewpoint safety factors have shown that sections 5, 6, 8, 7, 3, 1, 4, 2 were unstable, respectively. Compare the sections showed that the events of 4, 2, 1 and 3 have the most impact on sections usability, respectively.Results of the sensitivity analysis model to input parameters indicated that safety factor has the most sensitive to height, water level and cohesion between particles with a variation coefficient 55%, 17% and 10%, respectively.