Analysis of Flood Conveyance Capacity of Small and Medium-Sized River and Flood Managements

Abstract Recent years have witnessed great losses caused by floods due to the unknown of rivers’ flood conveyance capacities, which make it difficult for floods management. In particular, flood conveyance capacities of small and medium-sized rivers are usually designed to meet the flood with a return period of 10 years but these rivers have not been paid enough attention. After years of scouring and siltation, the flood conveyance capacities of the rivers are unknown, and flood disasters caused by reservoir discharge are unpredictable. The aim of this research is to set a standardized research process to find out the actual flood conveyance capacities of small and medium-sized rivers. The hydrodynamic model is constructed and calibrated to evaluate the river’s flood conveyance capacity. The design flood data are used to make the simulation, and the flood conveyance capacity of the river channel is evaluated combined with the actual situation of the river. Then with water level observation points settled, the dynamic process of water level of the river channel can be grasped and real-time assessment of flood risk of the river can be done. Taking the downstream of Yingna River, a typical small and medium-sized river flowing into the ocean, as an example, the results showed that this standardized process can provide a reference for the analysis of flood conveyance capacity of small and medium-sized rivers.