Use of soil data in a grid-based hydrological model to estimate spatial variation in changing flood risk across the UK
Use of soil data in a grid-based hydrological model to estimate spatial variation in changing flood risk across the UK
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DOI：
10.1016/j.jhydrol.2009.08.031
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发表时间：
2009-10-30
影响因子：
6.4
通讯作者：
Reynard, N. S.
中科院分区：
文献类型：
--
作者：
Bell, V. A.;Kay, A. L.;Reynard, N. S.
一个基于网格的径流路线和径流产生模型，配置为使用观测或区域气候模型(RCM)对降水量和潜在蒸发量(PE)的估计作为输入，以前曾被用于评估气候变化可能如何影响英国境内的河流流量。基于坡度的网格到网格(G2G)模型充分模拟了当前气候条件下高地形集水区的观测河流流量，但应用于低地形和/或以地下水为主的地区时则不太成功。该模型现在已得到改进，可以使用土壤数据集来配置控制每个网格单元内土壤水分和径流产生的概率分布存储。比较了这两个模型使用降雨观测和PE作为输入来模拟一系列英国集水区的量测河流流量的能力。在模型评估之后，作为两个水文模型的输入的观测降水和PE数据被用于当前(1961-1990)和未来(2071-2100)时间切片的25公里网格上的REM估计所取代。从两个时间片的水流模拟得出的洪水频率曲线首次用于估计英国境内1公里网格上所有河点的洪水等级变化地图。河流流量的估计变化具有高度的空间变异性，既反映了预测的气候变化，也反映了景观和气候变化的影响。这些地图还突出了两个模型所产生的气候影响预测之间的巨大差异。改进的基于土壤的G2G模型的结构和性能增加了它对流量变化的预测的信心，这些预测是气候变化情景的现实后果。使用重采样方法来识别这些投影可以被认为是稳健的区域。然而，由于所使用的气候变化情景只代表了未来气候的一种看似合理的演变，因此这里无法就预测的河流流量变化得出明确的信息。皇冠版权所有(C)2009由爱思唯尔出版。保留所有权利。
A grid-based flow routing and runoff-production model, configured to employ as input either observed or Regional Climate Model (RCM) estimates of precipitation and potential evaporation (PE), has previously been used to assess how climate change may impact river flows across the UK. The slope-based Grid-to-Grid (G2G) model adequately simulated observed river flows under current climate conditions for high relief catchments, but was less successful when applied to lower-relief and/or groundwater-dominated areas. The model has now been enhanced to employ a soil dataset to configure the probability-distributed store controlling soil-moisture and runoff generation within each grid-cell. A comparison is made of the ability of both models to simulate gauged river flows across a range of British catchments using observations of rainfall and PE as input. Superior performance from the enhanced G2G formulation incorporating the soil dataset is demonstrated.Following the model assessment, the observed precipitation and PE data used as input to both hydrological models were replaced by REM estimates on a 25 km grid for a Current (1961-1990) and a Future (2071-2100) time-slice. Flood frequency curves derived from the flow simulations for the two time-slices are used to estimate, for the first time, maps of changes in flood magnitude for all river points on a I km grid across the UK. A high degree of spatial variability is seen in the estimated change in river flows, reflecting both projected climate change and the influences of landscape and climate variability. These maps also highlight large differences between the climate impact projections arising from the two models. The improved structure and performance of the soil-based G2G model adds confidence to its projections of flow changes being realistic consequences of the climate change scenario applied. A resampling method is used to identify regions where these projections may be considered robust. However, with the climate change scenario used representing only one plausible evolution of the future climate, no clear message can be drawn here about projected river flow changes. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.