Analysis of riverbed form adjustment based on energy dissipation in the Inner Mongolia Reach of Yellow River

In order to study the adjustment regulation of riverbed form, in view of river energy dissipation, the 50-year river data collected from the Inner Mongolia Reach of Yellow River is analyzed by introducing the targets such as river work, longitudinal and transverse energy slope. It is found that the operation of upstream reservoirs has a great impact on the hydraulic regime of the river reach, such as decreasing the frequency of overbank flooding, increasing the channel width/depth ratio, and enhancing the horizontal activity in the river reach. In the process of riverbed form adjustment under the influence of reservoir operation, there is a close relation between the incoming sediment coefficient and the fluvial facies coefficient, and also between the average swing speed and the characteristic value of water and sediment. The study on the section configuration change, horizontal swing and the energy dissipation reveals that the river flow can directly impact the evolution of channel cross-section. The correlation among characteristics of runoff and riverbed morphology is constrained by the distribution of river energy dissipation. In this studying reach, it is found that the total water energy can roughly balance the required energy dissipation during the various periods of the year.