High-resolution flood modeling of urban areas using MSN_Flood
High-resolution flood modeling of urban areas using MSN_Flood
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DOI：
10.1016/j.wse.2017.10.003
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发表时间：
2017-01-01
影响因子：
4
通讯作者：
Nash, Stephen
中科院分区：
文献类型：
--
作者：
Hartnett, Michael;Nash, Stephen
虽然现有的水力模型已被用于模拟和预测城市洪水，这些模型大多是不够的，由于高空间分辨率所需的模拟流在城市洪泛区。在较粗分辨率的模型中嵌套高分辨率子域是一种有效的解决方案，可以同时计算潮汐、涌浪和高河流流量引起的洪水。MSN_Flood已被开发为包含嵌套域周围的移动边界，允许沿边界和域内部沿着交替进行淹没和干燥。与开放边界单元相邻的重影单元实际上将开放边界转换为内部边界。移动边界可以是多段的和不连续的，具有穿过边界的再循环流。当与定制的自适应插值方案相结合时，这种方法有助于动态内部边界。基于交替方向半隐式有限差分格式，MSN_Flood被用来后报科克市的主要洪水事件所造成的河流，潮汐和风暴潮过程的组合压力。结果表明，该模型是计算效率高，2米的高分辨率巢只用于城市淹没区。在其他地方，使用分辨率较低的巢。结果还表明，该模型是高度准确的，当与实测数据相比。该模型能够将嵌套子域嵌套边界时，是多段和高度复杂的海拔和速度的横向梯度。这是在非常高的分辨率下对城市洪泛区进行建模时的一个主要好处。(c)2017年河海大学。制作和主办：Elsevier B.V.
Although existing hydraulic models have been used to simulate and predict urban flooding, most of these models are inadequate due to the high spatial resolution required to simulate flows in urban floodplains. Nesting high-resolution subdomains within coarser-resolution models is an efficient solution for enabling simultaneous calculation of flooding due to tides, surges, and high river flows. MSN_Flood has been developed to incorporate moving boundaries around nested domains, permitting alternate flooding and drying along the boundary and in the interior of the domain. Ghost cells adjacent to open boundary cells convert open boundaries, in effect, into internal boundaries. The moving boundary may be multi-segmented and non-continuous, with recirculating flow across the boundary. When combined with a bespoke adaptive interpolation scheme, this approach facilitates a dynamic internal boundary. Based on an alternating-direction semi-implicit finite difference scheme, MSN_Flood was used to hindcast a major flood event in Cork City resulting from the combined pressures of fluvial, tidal, and storm surge processes. The results show that the model is computationally efficient, as the 2-m high-resolution nest is used only in the urban flooded region. Elsewhere, lower-resolution nests are used. The results also show that the model is highly accurate when compared with measured data. The model is capable of incorporating nested sub-domains when the nested boundary is multi-segmented and highly complex with lateral gradients of elevation and velocities. This is a major benefit when modelling urban floodplains at very high resolution. (c) 2017 Hohai University. Production and hosting by Elsevier B.V.