基于改进填洼模型的城市洪涝灾害计算方法

城市水文模型广泛应用于城市雨洪管理研究中,但由于它无法直接给出流域的淹没情况,制约了其在城市洪涝灾害评价中的应用,因此,有必要对其进行改进。本研究开发了考虑下游影响的填洼模型,并将其与较为成熟的城市水文模型相耦合,使改进后的模型可以模拟流域的淹没状况,并在北京市天堂河流域进行了试验研究。结果表明:改进后的模型可以快速模拟流域的淹没水深及淹没范围,其淹没水深结果与相关水动力学方法模拟结果较为一致。天堂河流域河道行洪能力低于20年一遇设计标准,流域洪水风险较大的区域集中在天堂河下游区域和田营沟与永北干渠的交汇处。若在下游区域进行开发,洪水风险还可能会继续增加。

Estimation of urban flooding processes based on enhanced inundation model

Urban hydrological models are widely used in urban water management. Compared with a hydrological-hydrodynamic model, urban hydrological models always show some limitations for estimating inundated area rapidly and therefore need to be enhanced. In this research, an enhanced inundation model which considers the feedback of water from lower depression element was developed and coupled to the SWMM model to simulate inundated areas in the Tiantang River basin in Beijing. A comparison with the results from a 2-D hydrodynamics model obtained in previous study showed that the enhanced model can quickly and accurately estimate the depth of inundation. The design standard of flood discharge capacity in the Tiantang River basin is lower than 20-year return period, and high-flood-risk areas are concentrated in downstream sections of the river and around the confluence of Tianting River and the Tianying and Yongbao channels. Flood risk in these downstream areas is also likely to increase with the development of new airports in the Tiantang River basin. This research proposes a new method to estimate urban inundation.