考虑下渗的河道与蓄滞洪区洪水演进过程模拟

Flood simulation in river and flood storage-detention area considering infiltration

基于霍顿(Horton)下渗和有限体积法,建立了考虑动态下渗的一二维耦合水动力学模型,并选择海河流域漳卫河系与大名泛区联合防洪体系作为典型应用区域,利用典型场次洪水对河道模型进行了率定和验证,同时探讨了下渗对于河道行洪、蓄滞洪区分洪以及洪水演进过程的影响。结果表明:考虑动态下渗的河道模型具有较高模拟精度,3场典型洪水洪峰误差都在10%以内;河道下渗会明显推迟蓄滞洪区的启用时间,并减小分洪流量和洪水总量;蓄滞洪区下渗对分洪过程影响较小,但会加快蓄滞洪区的退水速度。

A 1 D-2 D coupled hydrodynamic model considering the dynamic infiltration was developed based on the Horton infiltration formula and finite volume method. It was applied in the Zhangwei River system and Daming flood storage-detention area in the Haihe River Basin. The river model was calibrated and verified by using typical floods. At the same time, the influence of infiltration on flood discharge in river, flood diversion in the flood storage-detention area and flood evolution process were discussed. The results show that the river model considering dynamic infiltration has high simulation accuracy, and the peak error of three typical floods is within 10%. River infiltration will obviously delay the start-up time of the flood storage-detention area, and reduce the flood diversion flow and total amount. Infiltration in the flood storage-detention area has little effect on the flood diversion process, but it will accelerate the speed of water withdrawal in the flood storage-detention area.