Abstract. The interaction between waves, surges and astronomical tides can lead to high coastal total water level (TWL), which can in turn lead to coastal flooding. Here, a high resolution (1.5 km) simulation from a UK-focused regional coupled environmental prediction system is used to investigate the extreme events of winter 2013/4 around the UK and Irish coasts. The aim is to analyse the spatial distribution of coastal TWL and its components during this period by assessing 1- the relative contribution of different TWL components around the coast, 2- how extreme waves, surges and tide interacted and if they occurred simultaneously 3- if this has implications in defining the severity of coastal hazard conditions. The TWL components’ coastal distribution in winter 2013/4 was not constant in space, impacting differently over different regions. High (> 90^th percentile) waves and surges occurred simultaneously at any tidal stage, including high tide (7.7 % of cases), but more often over the flood tide. During periods of high flood risk a hazard proxy, defined as the sum of the sea surface height and half the significant wave height, at least doubled from average over ¾ of the coast. These results have important implications for the risk management sector.

中文翻译：

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英国和爱尔兰沿岸极端事件期间沿海高水位的分布

摘要。波浪，潮汐和天文潮之间的相互作用会导致沿海总水位（TWL）升高，进而导致沿海洪灾。在这里，采用了以英国为中心的区域耦合环境预测系统的高分辨率（1.5 km）模拟，以调查2013/4冬季英国和爱尔兰沿岸的极端事件。目的是通过评估1-分析沿海地区不同TWL成分的相对贡献，2-极端波，潮汐和潮汐如何相互作用以及它们是否同时发生3-如果分析此期间沿海TWL及其成分的空间分布，这对定义沿海灾害条件的严重性具有影响。TWL组件在2013/4冬季的沿海分布在空间上并不恒定，在不同地区的影响不同。高（> 90^个百分点）波和浪涌在任何阶段潮同时发生，包括高潮（占7.7％），但更多的时候在大潮。在洪水泛滥风险高的时期，危险代言人定义为海平面高度和有效波高的一半之和，至少比海岸3/4的平均值高出一倍。这些结果对风险管理部门具有重要意义。