Coupled modeling of rainfall-induced floods and sediment transport at the catchment scale  

作　　者：Ronglan Huang Yufang Ni Zhixian Cao 

机构地区：[1]State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan,China

出　　处：《International Journal of Sediment Research》2022年第6期715-728,共14页国际泥沙研究（英文版）

基　　金：This research was funded by the National Natural Science Foundation of China(Grant No.12072244)。

摘　　要：Rainfall-induced floods may trigger intense sediment transport on erodible catchments, especially on the Loess Plateau in China, which in turn modifies the floods. However, the role of sediment transport in modifying floods has to date remained poorly understood. Concurrently, traditional hydrodynamic models for rainfall-induced floods typically ignore sediment transport, which may lead to inaccurate results for highly erodible catchments. Here, a two-dimensional(2 D) coupled shallow water hydro-sedimentmorphodynamic(SHSM) model, based on the Finite Volume Method on unstructured meshes and parallel computing, is proposed and applied to simulate rainfall-induced floods in the Zhidan catchment on the Loess Plateau, Shaanxi Province, China. For six historical floods of return periods up to 2 years, the numerical results compare well with observations of discharge hydrographs at the catchment outlet. The computed runoff-sediment yield relation is quantitatively reasonable as compared with other catchments under similar geographical conditions. It is revealed that neglecting sediment transport leads to underestimation of peak discharge of the flood by 14%-45%, whilst its effect on the timing of the peak discharge varies for different flood events. For 18 design floods with return periods of 10-500 years, sediment transport may lead to higher peak discharge by around 9%-15%. The temporal pattern of concentrated rainfall in a short period may lead to a larger exponent value of the power function for the runoff-sediment yield relation. The current finding leads us to propose that incorporating sediment transport in rainfallinduced flood modeling is warranted. The SHSM model is applicable to flood and sediment modeling at the catchment scale in support of risk management and water and soil management.

关 键 词：CATCHMENT Floods Hydro-sediment-morphodynamic modeling Sediment transport Soil erosion 

分 类 号：P333[天文地球—水文科学]