An updated national-scale assessment of trends in UK peak river flow data: how robust are observed increases in flooding?
An updated national-scale assessment of trends in UK peak river flow data: how robust are observed increases in flooding?
复制标题
英国峰值河流流量数据趋势的最新国家规模评估：观察到的洪水增加有多强劲？
DOI：
10.2166/nh.2021.156
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发表时间：
2021
影响因子：
2.7
通讯作者：
S. Turner
中科院分区：
文献类型：
--
作者：
J. Hannaford;N. Mastrantonas;G. Vesuviano;S. Turner
英国最近发生的一系列洪水引发了人们对洪水是否会随着时间的推移而变得更加频繁或严重的问题的极大兴趣。近几十年来，许多趋势评估都处理了这一问题，通常得出的结论是，有证据表明，在全国范围内，洪水规模呈积极趋势。然而，趋势测试是一个有争议的领域，必须严格测试这些结论的弹性。在这里，我们使用英国国家洪水数据集（NRFA峰值流量）提供了一个全面的洪水量级趋势评估。重要的是，我们使用这个完整的数据集以及具有高质量洪水数据的近自然集水区的子集来评估趋势。虽然标题结论对于推进国家洪水风险政策是有用的，但对于实地洪水风险估计，重要的是要解开这些局部变化，以确定气候驱动的趋势如何与受到各种人为干扰和数据限制的更广泛数据集的趋势进行比较。我们还研究了敏感性的报告趋势的变化，在研究时间窗口使用“多时间”分析。我们发现，洪水增加的标题索赔一般持有区域到国家，虽然我们展示了一个更复杂的时空变化的图片。虽然一些报告的趋势，如英国北方和西部的洪水增加，似乎是强劲的，但其他地区的趋势在空间和时间上更为复杂-例如，近几十年的趋势不一定代表长期变化，在区域内（如英格兰东南部），可以发现增加和减少的趋势非常接近。虽然标题结论对于推进国家洪水风险政策是有用的，但对于洪水风险估计，重要的是要解开这些地方变化，这里提供的结果和方法工具包可以为从业人员提供这种支持信息。
A cluster of recent floods in the UK has prompted significant interest in the question of whether floods are becoming more frequent or severe over time. Many trend assessments have addressed this in recent decades, typically concluding that there is evidence for positive trends in flood magnitude at the national scale. However, trend testing is a contentious area, and the resilience of such conclusions must be tested rigorously. Here, we provide a comprehensive assessment of flood magnitude trends using the UK national flood dataset (NRFA Peak Flows). Importantly, we assess trends using this full dataset as well as a subset of near-natural catchments with high-quality flood data. While headline conclusions are useful for advancing national flood-risk policy, for on-the-ground flood-risk estimation it is important to unpack these local changes to determine how climate-driven trends compare with those from the wider dataset that are subject to a wide range of human disturbances and data limitations. We also examine the sensitivity of reported trends to changes in study time window using a ‘multitemporal’ analysis. We find that the headline claim of increased flooding generally holds up regionally to nationally, although we show a much more complicated picture of spatio-temporal variability. While some reported trends, such as increased flooding in northern and western Britain, appear to be robust, trends in other regions are more mixed spatially and temporally – for example, trends in recent decades are not necessarily representative of longer-term change, and within regions (e.g. in southeast England) increasing and decreasing trends can be found in close proximity. While headline conclusions are useful for advancing national flood-risk policy, for flood-risk estimation it is important to unpack these local changes, and the results and methodological toolkit provided here could provide such supporting information to practitioners.