Climate Change Impact on the Magnitude and Timing of Hydrological Extremes Across Great Britain
Climate Change Impact on the Magnitude and Timing of Hydrological Extremes Across Great Britain
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DOI：
10.3389/frwa.2021.684982
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
Rosanna A. Lane;A. Kay
中科院分区：
文献类型：
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作者：
Rosanna A. Lane;A. Kay
气候变化可能加剧极端水文现象，不仅改变洪水和干旱事件的规模，而且改变其发生的时间。在国家一级了解这些未来可能发生的水文极端变化，对于指导政策决定和确保采取适当的适应措施至关重要。在这里，气候变化对极端流量的大小和时间的影响在英国（GB）进行建模，使用来自最新英国气候预测产品（UKCP 18）和国家网格水文模型的气候数据集合。所有集合成员都显示出低流量的大幅减少，到2050-2080年，10年重现期低流量约为-90%至-25%。高流量的变化方向是不确定的，但在10年一遇的高流量增加超过9%是可能的，在全国大部分地区。两个极端的同时恶化（即，低流量减少，高流量增加）。流量时间的变化也预计;与苏格兰的年度最大流量，英格兰和威尔士的年度最大流量，以及英国的低流量。然而，由于年最大/最小流量时间的年际变化很大，这些变化一般没有统计意义。这些结果突出了适应战略的必要性，这些战略可以科普未来水文极端情况的广泛变化，并考虑到时间和幅度的变化。
Climate change could intensify hydrological extremes, changing not just the magnitude but also the timing of flood and drought events. Understanding these potential future changes to hydrological extremes at the national level is critical to guide policy decisions and ensure adequate adaptation measures are put in place. Here, climate change impact on the magnitude and timing of extreme flows is modelled across Great Britain (GB), using an ensemble of climate data from the latest UK Climate Projections product (UKCP18) and a national grid-based hydrological model. All ensemble members show large reductions in low flows, of around −90 to −25% for 10-year return period low flows by 2050–2080. The direction of change for high flows is uncertain, but increases in 10-year return period high flows of over 9% are possible across most of the country. Simultaneous worsening of both extremes (i.e., a reduction in low flows combined with an increase in high flows) are projected in the west. Changes to flow timing are also projected; with mostly earlier annual maximum flows across Scotland, later annual maximum flows across England and Wales, and later low flows across GB. However, these changes are generally not statistically significant due to the high interannual variability of annual maximum/minimum flow timing. These results highlight the need for adaptation strategies that can cope with a wide range of future changes in hydrological extremes, and consider changes in the timing as well as magnitude.