Storm clustering and its influence on coastal morphology and defence

人们普遍认为沿海地区在国家、欧洲和全球层面上都很重要，但它正面临着来自气候变化的越来越大的压力。最近的政府气候变化委员会2018年报告强调了英国洪水和海岸侵蚀威胁日益增加的紧迫性。它呼吁改进海岸结构破坏概率的计算，减少海岸侵蚀的不确定性，更好地了解海岸地貌及其对气候变化的反应。提高对极端事件特征和海岸动态响应的理解，对于实现这些目标至关重要。风暴通过极端的海平面和海浪强烈地影响着英国沿海的洪水和侵蚀。大多数以前的研究和风险评估倾向于只评估单个风暴的影响，很少考虑不同时间尺度上风暴事件的序列。极端海平面的时间聚类可能导致洪水或侵蚀损害的扩大，原因是对防御的侵蚀作用，以及海岸保护系统内自然（例如海滩）和人造（例如护岸）要素的恢复/修复时间不足。在海岸模拟研究中，这些条件几乎总是被认为是静态的，当几个事件快速连续发生时，这可能导致对洪水和侵蚀风险的低估。在之前epsrc资助的一个名为“洪水记忆”的大型项目的基础上，该博士学位旨在提高对风暴事件序列对硬海岸和软海岸动态响应的影响的理解。

The coastal zone is widely recognised as important at national, European and global levels, but is facing increasing pressures from climate change. The recent Government's Committee on Climate Change 2018 report highlights the urgency of increasing threats from flooding and coastal erosion in the UK. It calls for improvements in calculation of failure probabilities of coastal structures, reductions in uncertainty about coastal erosion and better understanding of coastal geomorphology, and its response to climate change. Improved understanding of the characteristics of extreme events, and the dynamic response of the coast, is essential to deliver on these aims.Storms strongly influence coastal flooding and erosion in the UK, via extreme sea levels and waves. Most previous studies and risk assessments have tended to only assess the impacts of individual storms and have rarely considered sequences of storm events on different time-scales. Temporal clustering of extreme sea levels could lead to amplified flood or erosion damages due to attritional effects on defences and inadequate recovery/repair time of natural (e.g., beaches) and man-made (e.g. revetments) elements within the coastal protection system. Conditions of these are almost always considered static in coastal modelling studies and this potentially leads to underestimation of flood and erosion risk when several events occur in rapid succession. Building on a large previous EPSRC-funded project called Flood MEMORY, this PhD aims to improve understanding of the impact that sequences of storm events have on the dynamic response of hard and soft coasts.