Research on Design Flood Simulation of Small Watershed based on Hydrodynamic Numerical Calculation
Based on the hydrodynamic numerical simulation method,the Xinjie River Basin in Huadu District,Guangzhou City is selected as the research area,and the design flood calculation is divided into natural and urban underlying surfaces in this paper.Using MIKE11 to construct one-dimensional river hydrodynamic model,MIKE Urban to construct pipe network flow model,MIKE FLOOD coupling one-dimensional hydrodynamic model and pipe network flow model,the coupling model is applied to the urban design flood simulation of Xinjiehe area.The typical frequency design flood at different river sections in Xinjiehe area is deduced.The design flood results calculated by the coupled model are compared with the design flood results calculated by the traditional hydrological analysis method,and the changes of the basin flood calculation after the urban pipeline network are analyzed.Comparing the calculation results of the combined unit line method and the urban flood coupling model,as a whole,the design flood results of coupled model calculation are larger,in line with the general area after urbanization design flood increased.However,for some rivers,the design flood result of coupling model is smaller than that of integrated unit line method,it may be related to the delay caused by the flow of rainfall runoff in complex urban pipe networks and the insufficient overcurrent capacity in small pipe diameters.