Efficient incorporation of channel cross-section geometry uncertainty into regional and global scale flood inundation models
Efficient incorporation of channel cross-section geometry uncertainty into regional and global scale flood inundation models
复制标题
将河道横截面几何不确定性有效纳入区域和全球规模洪水淹没模型
DOI：
10.1016/j.jhydrol.2015.07.026
复制
发表时间：
2015
影响因子：
6.4
通讯作者：
Neal J
中科院分区：
文献类型：
--
作者：
Neal J
本文探讨了区域到全球尺度的河流水力模型，这可能对波浪动力学模拟的影响，代表河道横截面几何结构差异的挑战。传统上，通道几何形状是使用数据定义的，但在更大的尺度上，采取这种方法所需的信息和模型结构并不存在。因此，我们提出了一个根本不同的方法，在通道几何结构的不确定性表示使用一个简单的参数化，然后可以通过校准或数据同化估计。本文首先概述了一个计算效率高的数值方案的发展，代表广义的通道形状，使用一个单一的参数，然后验证使用一个简单的直通道测试的情况下，并显示预测湿周在2%以内的渠道测试。应用到英国的塞文河，沿着与模型的敏感性分析，通道形状，深度和摩擦。通道形状参数，以改善模型模拟河流水位，特别是物理上更合理的通道粗糙度和深度参数范围。校准通道曼宁系数在矩形通道提供了类似的水位模拟精度的纳什-萨克利夫效率的模型，其中摩擦和形状或深度进行了校准。然而，矩形通道模型中校准的曼宁系数比该河段可能的物理现实值大1.2/3，这错误地将波浪通过该河段的传播时间减慢了几个小时。因此，对于在数据稀疏区域中应用的大尺度模型，校准通道深度和/或形状可能比假设矩形几何形状和单独校准摩擦更优选。
This paper investigates the challenge of representing structural differences in river channel cross-section geometry for regional to global scale river hydraulic models and the effect this can have on simulations of wave dynamics. Classically, channel geometry is defined using data, yet at larger scales the necessary information and model structures do not exist to take this approach. We therefore propose a fundamentally different approach where the structural uncertainty in channel geometry is represented using a simple parameterisation, which could then be estimated through calibration or data assimilation. This paper first outlines the development of a computationally efficient numerical scheme to represent generalised channel shapes using a single parameter, which is then validated using a simple straight channel test case and shown to predict wetted perimeter to within 2% for the channels tested. An application to the River Severn, UK is also presented, along with an analysis of model sensitivity to channel shape, depth and friction. The channel shape parameter was shown to improve model simulations of river level, particularly for more physically plausible channel roughness and depth parameter ranges. Calibrating channel Manning’s coefficient in a rectangular channel provided similar water level simulation accuracy in terms of Nash–Sutcliffe efficiency to a model where friction and shape or depth were calibrated. However, the calibrated Manning coefficient in the rectangular channel model was ∼2/3 greater than the likely physically realistic value for this reach and this erroneously slowed wave propagation times through the reach by several hours. Therefore, for large scale models applied in data sparse areas, calibrating channel depth and/or shape may be preferable to assuming a rectangular geometry and calibrating friction alone.
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影响因子：
5.4
作者：
Hall, Jim W.;Manning, Lucy J.;Hankin, Robin K. S.
通讯作者：
Hankin, Robin K. S.
影响因子：
6.4
作者：
Garcia-Pintado, Javier;Mason, David C.;Bates, Paul D.
通讯作者：
Bates, Paul D.
洪水风险评估的连续大规模模拟模型：概念验证
DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
D. Falter;N. Dung;S. Vorogushyn;K. Schröter;Y. Hundecha;H. Kreibich;H. Apel;F. Theisselmann;B. Merz
通讯作者：
B. Merz
影响因子：
3.3
作者：
K. Harwood;A. Brown
通讯作者：
K. Harwood;A. Brown
影响因子：
6.4
作者：
Garcia-Pintado, Javier;Neal, Jeff C.;Bates, Paul D.
通讯作者：
Bates, Paul D.