一维管网与二维地表双向耦合的城市暴雨内涝模拟

为快速、准确模拟城市暴雨内涝演化过程,提出一种排水管网与上覆地表动态水力交互方法,构建了一维管网模型(SWMM)与二维水动力(LISFLOOD-FP)双向耦合的模型,解决了一维管网和二维地表的双向流量交换和时间同步难题。以上海外高桥地区为例,采用两次短历时降雨过程对耦合模型进行校准和验证,比较分析了单向、双向耦合的淹没范围与水深变化。结果表明:双向耦合模拟精度较高,在研究区具有良好的适用性;对于占比80%以上的轻度(<0.2m)积水区,单向、双向耦合的模拟积水面积比为1.21;对于中等(0.2～0.3 m)和重度(>0.3 m)积水区,单向耦合模拟结果趋于严重,该比值分别增至1.88和2.1。所构建的双向耦合模型能够揭示城区内涝积水、扩散及消退的全过程,可用于城市暴雨内涝推演,为内涝治理和灾害防御提供科学依据。

Simulation of Urban Rainstorm Waterlogging with Bidirectional Coupling of One-Dimensional Sewer Network and Two-Dimensional Surface

To quickly and accurately simulate the evolution process of urban rainstorm waterlogging， a dynamic interaction method between underground sewer network and above surface was proposed， and a bidirectional coupling model of SWMM /LISFLOOD-FP was constructed to solve the two-way flow exchange and time synchronization problems. Taking the Waigaoqiao area of Shanghai as an example， the coupling model was calibrated and verified using two short-duration rainfall processes， and the simulation results of unidirectional and bidirectional coupling models were compared and analyzed. The results show that the bidirectional coupling model has a higher simulation accuracy and a better applicability in the study area. For the mild （<0.2 m） waterlogged area that accounts for more than 80 % of the submerged area， the ratio of simulated waterlogged area between unidirectional and bidirectional coupling models is 1.21. However， for moderate （0.2-0.3 m） and heavy （>0.3 m） waterlogged areas， the unidirectional coupling simulations tend to overestimate， and the ratios increase to 1.88 and 2.1， respectively. The bidirectional coupling model can effectively reveal the whole process of urban stormwater accumulation， diffusion and regression， which can be used for urban rainstorm waterlogging simulation and inference， and provide scientific basis for waterlogging control and disaster prevention.