Riverbank erosion: factors, mechanism, human activity

The riverbank erosion produces a great risk for the urban development, structures and communications located on the banks. Bank erosion, as an integral part of the lateral river channel migrations, is a multi-factorial phenomenon. Empirical evidence suggests that the riverbank erosion depends on the size of the river, the morphology of the bends, water flow; however, a big role plays erosion resistance of the banks, due to their structure and vegetation. It varies at changeable riverbank soils wetting in accordance with the hydrological regime of the river. Human activity contributes significantly to the intensification of lateral migrations, especially the construction of reservoirs that change the hydrological regime of rivers and sediment transport. Incision, daily flow regulation, redistribution of annual runoff, reducing the sediment load are the main factors that intensify the riverbank erosion. As an example, the situated downstream of the dam sections of the Volga River and Sheksna River in the Rybinsk City were examined and all these factors were revealed there themselves clearly. Considering these factors allowed predicting the riverbank erosion and provided the basis for bank protection program.