Modeling Extreme Flood Events in the Yellow River Using Unstructured Grids

Abstract

Abstract. Severe flood events in China are a common cause of life losses. Many efforts have been carried out by the Yellow River Conservancy Commission (YRCC) to understand flood development and impact on the Yellow River. Modeling approaches based on discretization of the modeled domain in square and rectangular grids have great importance in the management of rivers, but they usually present two drawbacks: the required accuracy of the meandering of wide long rivers is not well represented, and the need to use many grid cells reduces computational speed. Modeling and simulation of extreme flood events using unstructured grids has not yet been applied to the Yellow River. This study shows how such a method can be beneficial to decision makers in the Yellow River region in case of flood events. The research shows that a flexible mesh discretization of the domain can overcome the two drawbacks. Along with a test of the proposed modeling method, new characteristics of the spatial evolution of flood events in the Yellow River emerged and are presented, showing the capabilities of DFLOW-FM software in modeling such a complex system.