Synthesising Unprecedented Coastal Conditions: Extreme Storm Surges (SUCCESS)

该项目将与两个项目合作伙伴(环境署和法国电力公司能源)合作，这些合作伙伴拥有大量资产和基础设施，面临极端风暴潮的风险。对于这两个合作伙伴来说，该项目将提供对看似合理的沿海极端潮汐和海浪事件对关键基础设施的功能、弹性、设计和保护标准的影响的了解。它将使他们和其他洪水和海岸侵蚀风险管理当局更好地了解当前和未来的保护标准。对于关键的沿海地区--与我们的合作伙伴一起确定--我们将综合一些“黑天鹅”风暴潮--这些事件没有被观测到，但在物理上是可信的。这是以前从未对热带外天气系统做过的事情。重要的是对观测到的自然变化范围以外的风暴进行抽样，因为我们对严重风暴潮的记录可能太短(我们在60年内只发生过两次极端的北海风暴潮--分别在1953年和2013年)。为此，我们将从再分析数据中对欧洲风暴系统进行分析和分组，然后使用一个经过充分试验和测试的预报工具(由英国气象局提供给我们)扰乱大气系统。修改后的风压场将驱动风暴潮和波浪耦合模式，以产生合理的最坏情况。我们的工作将为最坏情况下的风暴潮提供一个可信的替代方案，补充仅从气候模型获得的H++情景。该项目的成果将有助于我们的项目合作伙伴和其他利益攸关方规划和缓解、沿海基础设施的选址和保护以及长期投资决策。我们的成果将采取以下形式：受影响地区风暴潮和海浪的二维数据场(与合作伙伴共同确定)；对这些地区极值统计数据的新计算；对潮汐/涌浪/波浪组合的逐个站点分析，然后提供给两个合作伙伴的下游建模。对环境署来说，新的数据将纳入国家和/或地方洪水风险和预报模型，以帮助了解此类事件将产生什么影响，从而为投资决策和事件准备提供信息。这些产出还将用于对目前估计极端海平面的最佳做法统计方法进行质量控制，并推广这些方法。对于EDF Energy，新数据将纳入他们目前估计极端海平面回归水平的统计方法，并提供信息，可用于针对不同自然灾害的可能最大极端水平和10000年水平下限的战略决策。

This project will engage with two project partners (Environment Agency and EDF energy) with significant assets and infrastructure at risk from extreme storm surges. For both partners this project will deliver understanding of the impacts of plausible extreme coastal surge and wave events on the function, resilience, design and standard of protection of key infrastructure. It will provide them and other Flood and Coastal Erosion Risk Management Authorities with an improved level of understanding around current and future standards of protection. For key coastal regions - determined with our partners - we will synthesise a number of "black swan" storm surges - events that have not been observed but that are physically plausible. This has never previously been done for extra-tropical weather systems. It is important to sample storminess beyond the observed range of natural variability since our record of severe storm surges is probably too short (we have only had two extreme North Sea storm surges in 60 years - in 1953 and 2013). We will do this by analysing and grouping European storm systems from reanalysis data, and then perturbing the atmospheric systems using a well tried and tested forecasting tool (made available to us by the Met Office). The modified wind and pressure fields will drive coupled storm surge and wave models to create the plausible worst cases. Our work will provide a credible alternative for worst case storm surges that complements the H++ scenarios obtained from climate models alone. The results of the project will assist our project partners and other stakeholders in planning and mitigation, the siting and protection of coastal infrastructure, and long term investment decisions. Our deliverables will take the form of: 2-D data fields for storm surges and waves along the affected regions (determined with the partners); new calculations of extreme value statistics for those regions; site-by-site analyses of tide/surge/wave combinations that then feed into the downstream modelling of the two partners. For the Environment Agency, the new data would feed into National and / or local flood risk and forecasting models to help understand what impacts would be associated with such events to inform investment decisions and incident preparedness. The outputs would also be used both to quality control the current best-practice statistical methods for estimation of extreme sea levels and extend those. For EDF Energy, the new data will feed into their current statistical methodology for estimating return levels of extreme sea levels and provide information that could be used in strategic decisions on probable maximum extremes and lower bounds on the 10,000-year level for different natural hazards.