There is unequivocal evidence that global sea levels are rising. It is therefore inevitable there will be socioeconomic impacts as a result of this. To aid mitigation, and the implementation of adaptation measures, it is vital the magnitude of the potential impact is quantified. Current approaches in the UK make simplifying assumptions regarding the relationship between present-day and future economic damage relating to coastal flood risk. The analysis undertaken here supports studies of an improved impact of sea level rise by providing national-scale estimates of changes in wave overtopping rates and flood defence overflow rates, as a result of different amounts of sea level rise. The analysis involves the application of components of an existing risk-based coastal flood risk analysis method. A subset of almost 600 flood defence assets around the country has been analysed for sea level rise rates up to 1 m. The resulting analysis shows that, on average, the wave overtopping rate increases by up to 150 times above present-day rates for lower return periods and by up to five times for higher return periods. This differential arises as a result of non-linearities in overtopping rates with increasing extreme sea levels.

中文翻译：

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海平面上升对英格兰海岸周围波浪超越率的影响

有明确的证据表明全球海平面正在上升。因此，不可避免地会产生社会经济影响。为了帮助缓解和实施适应措施，量化潜在影响的程度至关重要。英国目前的方法对与沿海洪水风险相关的当前和未来经济损失之间的关系进行了简化假设。这里进行的分析通过提供不同海平面上升幅度导致的波浪越浪率和防洪溢流率变化的全国范围估计，支持海平面上升影响改善的研究。该分析涉及现有基于风险的沿海洪水风险分析方法的各个组成部分的应用。已对全国近 600 个防洪资产的子集进行了海平面上升率高达 1 m 的分析。结果分析表明，平均而言，在较低回报期，波浪越顶率比当前比率高出 150 倍，在较高回报期则最高可高出 5 倍。这种差异是由于随着极端海平面的增加而出现的非线性超越率的结果。