High‐flow and flood trends in a network of undisturbed catchments in the UK
High‐flow and flood trends in a network of undisturbed catchments in the UK
复制标题
英国未受干扰的集水区网络中的高流量和洪水趋势
DOI：
10.1002/joc.1643
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
T. Marsh
中科院分区：
文献类型：
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作者：
J. Hannaford;T. Marsh
这项研究提出了趋势测试的结果，适用于高流量和洪水记录从网络的集水区在英国。这些河流的水流状况相对不受人为影响，从而能够表征自然气候驱动的趋势。趋势检验应用于洪水量级和频率指标，以及高流量量级（10天和30天最大值）和持续时间（高流量的流行率）指标。在2003年之前的30-40年中，所有指标都出现了显著的积极趋势，这些趋势主要出现在英国北方和西部地区的高地、受海洋影响的集水区。结果表明，北方和西部地区的高流量和洪水泛滥趋势更加持久，但洪水强度的趋势并不那么普遍。在英国低地几乎没有发现引人注目的趋势，在那里，显著的高流量趋势受到2000/1年异常潮湿的冬季一系列显著洪水事件的影响。观察到的趋势与气候变化情景下极端降雨量变化的一些预测相似。然而，许多北方和西部集水区的高流量指标与北大西洋涛动（NAO）相关，因此最近的增加可能是由于自20世纪60年代以来向更普遍的正NAO转变造成的。使用6个较长（>55年）的水文记录将近期趋势置于历史背景中;在较长时间序列中几乎没有趋势的证据，但记录中的波动表明近期趋势可能受到多年代际变化的影响，这对趋势检测具有重要影响，因为大多数英国计量站记录开始于高流量的相对静止期。版权所有© 2007皇家气象学会
This study presents the results of trend tests applied to high‐flow and flood records from a network of catchments in the UK. These rivers have flow regimes which are relatively undisturbed by anthropogenic influences, enabling a characterization of natural, climate‐driven trends. Trend tests were applied to indicators of flood magnitude and frequency, and also indicators of high‐flow magnitude (10‐ and 30‐day maxima) and duration (prevalence of high‐flows). Significant positive trends over the 30–40 years leading up to 2003 were identified in all indicators, and these were primarily found in upland, maritime‐influenced catchments in northern and western areas of the UK. The results suggest a trend towards more protracted high‐flows and more spate conditions in northern and western areas, but trends in flood magnitude were less prevalent. Few compelling trends were found in the English lowlands, where significant high‐flow trends were influenced by a sequence of notable flood events through the exceptionally wet winter of 2000/1. The observed trends have parallels with some projections for extreme rainfall changes under climate change scenarios. However, high‐flow indicators for many northern and western catchments were correlated with the North Atlantic Oscillation (NAO), so recent increases are probably caused by a shift towards a more prevalent positive NAO since the 1960s. Six longer (>55 years) hydrometric records were used to place recent trends in a historical context; there was little evidence for trend in the longer time series, but fluctuations in the records suggest that recent trends may be influenced by multi‐decadal variability, which has important consequences for trend detection as the majority of UK gauging station records begin in a relatively quiescent period for high‐flows. Copyright © 2007 Royal Meteorological Society