Research on the Hydrodynamic Characteristics of Typical Encountering Flood in the Lower Han River, China

Abstract

Han River is the largest tributary of the Yangtze River, the hydrodynamics characteristics in the lower Han River is under the influence of upstream flow and sediment discharge and the backwater level of Yangtze River. Based on the one-dimensional hydrodynamic mathematical model, the hydrodynamic characteristics in the lower Han River were simulated and analyzed. The results show that the hydrodynamic characteristics change significantly under the different combinations of stage-discharge in the downstream and upstream. On the one hand, when the autumn flood occurred in the Han River basin after the flood season in the Yangtze River, there will be a sharp increase of water surface gradients and flow velocity. On the other hand, there is also an obvious decrease of flow velocity and water surface gradients when the multi-year average discharge coupling with the high water level of Yangtze River. It should be highly attentive to the hydrodynamic characteristic variation with the different combinations of stage-discharge in the two rivers, which is adverse to the dike safety, channel erosion and the waterway maintenance along the channel of Han River.