Use of a grid-based hydrological model and regional climate model outputs to assess changing flood risk
Use of a grid-based hydrological model and regional climate model outputs to assess changing flood risk
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使用基于网格的水文模型和区域气候模型输出来评估不断变化的洪水风险
DOI：
10.1002/joc.1539
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Bell V
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文献类型：
--
作者：
Bell V
一个基于网格的流量路由和径流产生模型，配置为采用区域气候模型（RCM）降水估计作为输入，用于评估气候变化对英国流域河流流量的影响。该模型，网格到网格模型或G2 G，先前已根据当前气候条件下观测到的河流流量进行了校准和评估。在这里，G2 G分布式模型与集总流域模型（参数广义PDM）一起应用于模拟河流流量并推导洪水频率曲线。使用了两组RCM降水时间序列，在25 km网格上，每小时一次：（1）当前（1961-1990）和（2）未来（2071-2100）。当前降水系列中的一个极端降雨事件的影响是在当前降雨条件下提高一些集水区高重现期的估计峰值流量。未来流量系列不包含可比较的流量峰值。这显著影响了洪水频率曲线的比较，这些曲线是通过使用当前和未来的降水估计值进行流量模拟得出的。结果的这种可变性以及对一两次极端降雨事件的依赖性，突出表明有必要为洪水影响研究审查一套以上的当前/未来降雨情景。在没有一个正式的合奏气候预测，一个restaurant方法被用来调查的鲁棒性模拟洪水频率的变化。在较高重现期的洪水频率的变化，并不奇怪，发现一般不太强大，比在较低重现期。英格兰南部和东部的集水区尤其如此，这些集水区特别受到当前降水系列中极端降雨事件的影响。版权所有© 2007皇家气象学会
A grid‐based flow routing and runoff‐production model, configured to employ regional climate model (RCM) precipitation estimates as input, is used to assess the effects of climate change on river flows in catchments across the UK. This model, the Grid‐to‐Grid model or G2G, has previously been calibrated and assessed with respect to observed river flows under current climate conditions. Here, the G2G distributed model together with a lumped catchment model, the parameter‐generalized PDM, are applied to simulate river flow and derive flood frequency curves. Two sets of RCM precipitation time‐series, on a 25‐km grid and at hourly intervals, are used: (1) Current (1961–1990) and (2) Future (2071–2100). The effect of one extreme rainfall event in the current precipitation series is to raise the estimated peak flows for some catchments for high return periods under present day rainfall conditions. The future flow series does not contain a comparable flow peak. This significantly affects comparison of the flood frequency curves derived from the flow simulations obtained using the current and future precipitation estimates. Such variability in the results and the dependence on one or two extreme rainfall events emphasizes the need to examine more than one set of current/future precipitation scenarios for flood impact studies. In the absence of a formal ensemble of climate predictions, a resampling method is used to investigate the robustness of the modelled changes in flood frequency. Changes in flood frequency at higher return periods are, not surprisingly, found to be generally less robust than at lower return periods. This is particularly the case for catchments in the south and east of England, which were especially affected by the extreme rainfall event in the current precipitation series. Copyright © 2007 Royal Meteorological Society