A comparison of one‐ and two‐dimensional approaches to modelling flood inundation over complex upland floodplains
A comparison of one‐ and two‐dimensional approaches to modelling flood inundation over complex upland floodplains
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复杂高地洪泛区洪水淹没建模的一维和二维方法的比较
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发表时间：
2007
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通讯作者：
D. Yu
中科院分区：
文献类型：
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作者：
V. Tayefi;S. Lane;R. Hardy;D. Yu
本文研究了洪水淹没中一个研究严重不足的方面，即具有地形复杂的洪泛区的高地环境。尽管高分辨率地形数据（如激光雷达数据）的存在提高了河流洪水淹没预测的质量，但对于地形和拓扑（即洪泛区特征的连通性）复杂的情况，为此目的的水力模型的最佳维度尚未得到充分评估。在本文中，我们对高地洪水淹没的三种处理方法进行了比较，使用了：(a) 一维（1D）模型（HEC - RAS v.3·1·2），其域定义为一系列扩展横截面；(b) 相同的1D模型，但洪泛区由一系列蓄水单元定义，根据洪泛区拓扑特征与主河道和洪泛区上的其他蓄水单元水力相连；(c) 二维（2D）扩散波处理方法，同样明确表示洪泛区结构特征。必要的地形和拓扑数据是使用激光雷达和英国地形测量局的陆地线数据得出的。这三个模型在英国沃尔夫河6公里的高地河段进行了测试。通过与实测淹没范围进行比较对模型进行了评估。结果表明，扩展横截面和蓄水单元1D模式在概念上都存在问题。它们还导致模型预测效果较差，需要对主河道到洪泛区的流量进行错误的参数设定，才能接近评估2D扩散波处理方法时所观察到的一致性水平。我们得出结论，对于复杂的洪泛区配置，利用现有的技术，耦合的1D - 2D处理方法可能提供最佳的建模方法。版权所有© 2007约翰威立父子有限公司
A much understudied aspect of flood inundation is examined, i.e. upland environments with topographically complex floodplains. Although the presence of high‐resolution topographic data (e.g. lidar) has improved the quality of river flood inundation predictions, the optimum dimensionality of hydraulic models for this purpose has yet to be fully evaluated for situations of both topographic and topological (i.e. the connectivity of floodplain features) complexity. In this paper, we present the comparison of three treatments of upland flood inundation using: (a) a one‐dimensional (1D) model (HEC‐RAS v. 3·1·2) with the domain defined as series of extended cross‐sections; (b) the same 1D model, but with the floodplain defined by a series of storage cells, hydraulically connected to the main river channel and other storage cells on the floodplain according to floodplain topological characteristics; (c) a two‐dimensional (2D) diffusion wave treatment, again with explicit representation of floodplain structural features. The necessary topographic and topological data were derived using lidar and Ordnance Survey Landline data. The three models were tested on a 6 km upland reach of the River Wharfe, UK. The models were assessed by comparison with measured inundation extent. The results showed that both the extended cross‐section and the storage cell 1D modes were conceptually problematic. They also resulted in poorer model predictions, requiring incorrect parameterization of the main river to floodplain flux in order to approach anything like the level of agreement observed when the 2D diffusion wave treatment was assessed. We conclude that a coupled 1D–2D treatment is likely to provide the best modelling approach, with currently available technology, for complex floodplain configurations. Copyright © 2007 John Wiley & Sons, Ltd.