雨水检查井概化对城市内涝一二维耦合模拟结果影响研究

Research on the Impact of Manhole Covers on Urban Flooding Simulation in 1D-2D Coupled Hydrodynamic Models

为探明城市内涝一二维模型耦合过程中,检查井井盖对节点溢流和二维积水特征的影响,以重庆市悦来会展城某排水片区为研究区,耦合暴雨径流管理模型(Storm Water Management Model,SWMM)与有限体积海洋模型(Finite-Volume Coastal Ocean Model,FVCOM)。通过分析溢流过程中检查井井盖的作用水头,对耦合模型的溢流节点计算水头进行校正。基于历史降雨对模型进行验证,并应用耦合模型模拟分析不同井盖概化方式下溢流节点数量、位置分布、积水深度和积水面积的差异。结果表明:降雨重现期较小时(如低于50 a一遇),管网溢流程度较轻,两种井盖概化方式下的节点溢流情况无太大差别;与不考虑井盖影响相比,50 a和百年一遇时,模型中考虑井盖影响下的检查井溢流个数分别从533和597减少为189和431,最大积水深度分别从0.46 m和0.53 m下降到0.38 m和0.48 m,最大积水面积分别从3.50 km^(2)和3.85 km^(2)下降至2.10 km^(2)和3.05 km^(2);识别出3处主要易涝点,分别位于滨江路与同茂大道交汇处、悦城路北段和翠岗路南段末端。因此,在管网发达的城市区域构建一二维水动力耦合模型进行极端内涝风险模拟分析时,应充分考虑雨水检查井井盖在模型中合理的概化,提高模拟结果的准确度。

In order to investigate the effects of well covers on node overflow and two-dimensional water accumulation characteristics during the coupling process of 1D-2D dimensional model in urban waterlogging,this paper takes a drainage area of Yuelai Convention and Exhibi-tion City of Chongqing as the research area.The study employs the Storm Water Management Model(SWMM)for stormwater runoff manage-ment and couples it with the Finite-Volume Coastal Ocean Model(FVCOM).By analyzing the role of inspection well covers in the head of water during the overflow process,corrective adjustments are made to the head calculations for overflow nodes in the coupled model.The model is validated based on historical rainfall,and the coupled model is applied to simulate and analyze the differences in the number of overflow nodes,their spatial distribution,inundation depth,and inundation area under different well cover generalization scenarios.The re-sults indicate that during short return periods of heavy rainfall(such as less than once every 50 years),the degree of network overflow is rela-tively light,with no significant difference in node overflow between the two generalized manhole cover scenarios.Compared to not consider-ing the impact of manhole covers,the number of overflowing inspection wells in the model considering the impact of manhole covers de-creased from 533 and 597 to 189 and 431 for return periods of 50 years and 100 years respectively.The maximum waterlogging depth de-creased from 0.46 m and 0.53 m to 0.38 m and 0.48 m,and the maximum waterlogging area decreased from 3.50 km^(2)and 3.85 km^(2)to 2.10 km^(2)and 3.05 km^(2).Three main waterlogging-prone points were identified,which were located at the intersection of Binjiang Road and Tong-mao Avenue,the north section of Yuecheng Road and the south section of Cuigang Road.Therefore,when conducting extreme urban inunda-tion risk simulation and analysis using 1D-2D coupled hydrodynamic model in densely networked urban areas,it is crucial to adequately consider the rational generalization of rainwater manhole covers in the model to enhance the accuracy of simulation results.