Abstract:
In order to accurately simulate the whole urban flooding processes and assess the flood risks to people and vehicles in floodwaters, a 2D-surface and a 1D-sewer integrated hydrodynamic model was proposed in this study, with the module of flood risk assessment of people and vehicles being included. The proposed model was firstly validated by a dual-drainage laboratory experiment on the flood inundation process over a typical urban street, and the relative importance of model parameters and model uncertainties were evaluated using the GSA-GLUE method. Then the model was applied to simulate an actual urban flooding process that occurred in Glasgow, UK, with the influence of the sewer drainage system on flood inundation processes and hazard degree distributions of people and vehicles being comprehensively discussed. The following conclusions are drawn from this study: (i) The proposed model has a high degree of accuracy with the NSE values of key hydraulic variables greater than 0.8 and the GSA indicates that Manning roughness coefficients for surface and sewer flows, inlet weir and orifice discharge coefficients, are the most relevant parameters to influence the simulated results; (ii) vehicles are vulnerable to larger water depths while human stability is significantly influenced by higher flow velocities, with the overall flood risk of people being less than that of vehicles; and (iii) about 88.7% of the total inflow volume was drained to the sewer network, and the sewer drainage system greatly reduced the flood risks to people and vehicles except the local areas with large inundation water depths, where the sewer drainage increased the local flow velocity leading to higher flood risks especially for people.
摘要:
为了准确模拟整个城市洪水过程,评估洪水中人员和车辆的洪水风险,本研究提出了二维表面和一维下水道综合水动力模型,包括人员和车辆的洪水风险评估模块。首先通过对典型城市街道洪水淹没过程的双排水实验室实验验证了所提出的模型,并使用GSA-GLUE方法评估模型参数和模型不确定性的相对重要性。然后将该模型应用于模拟格拉斯哥发生的实际城市洪水过程,英国,全面讨论了下水道排水系统对洪水淹没过程的影响以及人员和车辆的危险程度分布。从这项研究中得出以下结论:(i)所提出的模型具有很高的准确性,关键水力变量的NSE值大于0.8,GSA表明地表和下水道流的曼宁粗糙度系数,入口堰和孔口排放系数,是影响模拟结果的最相关参数;(ii)车辆容易受到较大水深的影响,而人体稳定性受到较高流速的显著影响,人的整体水浸风险低于车辆;(iii)约88.7%的总流入量排入污水管网,下水道排水系统大大降低了洪水对人员和车辆的风险,除了淹没水深较大的地区,下水道的排水增加了局部流速,导致洪水风险更高,尤其是对人们来说。