Simulation of the Sedimentation Processes of the Xiaobeiganliu Reach, Yellow River and the Lower Wei River

The Xiaobeiganliu and lower Wei River (LWR) have undergone severe sedimentation since the operation of Sanmenxia reservoir. The base-level of the channel reaches at Tongguan rose obviously and the incoming water discharge and sediment load varied significantly as a result of nature factors and human-induced disturbance. The fluvial processes of theXiaobeiganliu and LWR were complexly affected by the combined effects of the variation of water discharge and sediment load as well as the channel bed elevation at Tongguan. It's assumed that channel reaches in their potential equilibrium state, compared to the initial boundaries, have a deposition body with a triangular longitudinal shape determined by the variation of Tongguan elevation Delta Z, initial channel bed slope J(0) and the potential equilibrium slope J(e). Based on the delayed response model and an equation developed for calculating the volume of triangular deposition body, a method for simulating the erosion and deposition processes of the river reaches was proposed. The accumulated deposition processes of the river reaches during 1960 and 2011 were well simulated using the proposed method. The results also showed that the method takes into account the effects of both Tongguan elevation and the water and sediment conditions.