Simulation of Hydraulic Structures in 2D High-Resolution Urban Flood Modeling
Simulation of Hydraulic Structures in 2D High-Resolution Urban Flood Modeling
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DOI：
10.3390/w11102139
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发表时间：
2019-09
期刊：
影响因子：
3.4
通讯作者：
Yunsong Cui;Q. Liang;Gang Wang;Jiaheng Zhao;Jinchun Hu;Yuehua Wang;X. Xia
中科院分区：
文献类型：
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作者：
Yunsong Cui;Q. Liang;Gang Wang;Jiaheng Zhao;Jinchun Hu;Yuehua Wang;X. Xia
由于排水能力不足、防洪设施失效等原因造成的城市洪涝灾害，往往具有很强的瞬变水动力特性。可靠、高效地预测和预报这些城市山洪灾害仍然是一个巨大的技术挑战。同时，在城市环境中，城市洪水的水动力和过程可能会受到流量调节和防洪水利基础设施系统（如闸门）的影响，这在城市洪水模型中应得到有效考虑。然而，在二维城市洪水模拟中，水工建筑物的直接模拟并不是当前的实践。本研究旨在发展一种稳健的数值方法，以直接模拟闸门结构在二维高分辨率城市洪水模型中的影响。开发了一种新的建模组件，并完全耦合到有限体积Godunov型冲击捕获浅水模型，直接模拟高度瞬态洪水波通过水工建筑物。不同的耦合方法，即，通量项耦合和源项耦合，并进行了比较。一个溃坝分析试验的数值试验表明，通量项耦合方法可以得到更精确的结果，其相对于水位变化的均方根误差比源项耦合方法小28%~ 38%。因此，采用通量项耦合方法来改进现有的城市洪水模型，并通过再现在浙江省水利与河口研究所水力实验室进行的部分打开闸门的水槽中的洪水演进的实验室实验，进一步验证。数值计算结果与实验测量相比，有利的最大均方根误差为0.0851的所有个人测试。结果表明，采用通量耦合方法建立的洪水模型能够较准确地模拟水工建筑物的水流运动，提高了城市洪水模拟的预测能力。
Urban flooding as a result of inadequate drainage capacity, failure of flood defenses, etc. is usually featured with highly transient hydrodynamics. Reliable and efficient prediction and forecasting of these urban flash floods is still a great technical challenge. Meanwhile, in urban environments, the flooding hydrodynamics and process may be influenced by flow regulation and flood protection hydraulic infrastructure systems, such as sluice gates, which should be effectively taken into account in an urban flood model. However, direct simulation of hydraulic structures is not a current practice in 2D urban flood modeling. This work aims to develop a robust numerical approach to directly simulate the effects of gate structures in a 2D high-resolution urban flood model. A new modeling component is developed and fully coupled to a finite volume Godunov-type shock-capturing shallow water model, to directly simulate the highly transient flood waves through hydraulic structures. Different coupling approaches, i.e., flux term coupling and source term coupling, are implemented and compared. A numerical experiment conducted for an analytical dam-break test indicates that the flux term coupling approach may lead to more accurate results, with the calculated RMSE against water level 28%–38% less than that produced by the source term coupling approach. The flux term coupling approach is therefore adopted to improve the current urban flood model, and it is further tested by reproducing the laboratory experiments of flood routing in a flume with partially open sluice gates, conducted in the hydraulic laboratory at the Zhejiang Institute of Hydraulics and Estuary, China. The numerical results are compared favorably with experimental measurements, with a maximum RMSE of 0.0851 for all the individual tests. The satisfactory results demonstrate that the flood model implemented with the flux coupling approach is able to accurately simulate the flow through hydraulic structures, with enhanced predictive capability for urban flood modeling.