Rapid urbanisation along the coasts of the world in recent decades has increased their vulnerability to storm surges, especially in response to mean sea level rise. The unique geographical and social conditions of Copenhagen, a major European coastal city, have prompted urban expansion along Køge Bay to the south of the city. However, this new urbanisation area is confronted with the common obstacle of developing a coastal defence strategy, i.e., the lack of long-term observational data required to determine a reliable storm surge protection level. This study aims to address this issue by developing a framework that integrates historical records of extreme storm surge events into coastal defence strategies, using Copenhagen as a case study. We propose a four-step work framework, including (1) Data collection and analysis: We collected and analysed data from neighbouring cities and used modelling and reanalysis data sets. By combining these sources, we aim to reconstruct historical time series for the study site dating back to 1836. This extended information set enhances our understanding of past storm surge events. (2) Statistical modelling and forecasting: Using Bayesian statistical methods, we fitted the historical storm surge data to appropriate probability distributions. This enabled us to generate probabilistic forecasts of storm surge magnitudes, providing insight into the likelihood of future events and their potential impacts on the coastal area. (3) Sensitivity analyses: We performed sensitivity experiments using Markov chain Monte Carlo (MCMC) methods to identify the most influential parameters, such as thresholds, that affect storm surge levels. This analysis improved our understanding of the key drivers of storm surge events and their uncertainties, further informing coastal defence strategies. (4) Expert judgement and risk management: Expert judgements are implemented to establish the necessary security level to manage flood risks in the city. This helps to ensure that high-impact, low-probability events are adequately considered in risk management efforts. Following this framework, we can develop a comprehensive understanding of storm surge risks in the urbanised region south of Copenhagen and use historical data to inform coastal defence strategies. This study emphasises the importance of incorporating long-term observational data and expert insights to improve the resilience of coastal cities facing the challenges of urbanisation and climate change.

中文翻译：

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将历史风暴潮事件纳入哥本哈根地区的洪水风险安全


近几十年来，世界沿海地区的快速城市化增加了它们对风暴潮的脆弱性，特别是在平均海平面上升的情况下。欧洲主要沿海城市哥本哈根独特的地理和社会条件，促使城市沿克厄湾向城市南部扩张。然而，这一新型城镇化地区面临着制定海防战略的共同障碍，即缺乏确定可靠的风暴潮防护水平所需的长期观测数据。本研究旨在通过开发一个框架来解决这个问题，该框架将极端风暴潮事件的历史记录整合到海岸防御策略中，并以哥本哈根为案例研究。我们提出了一个四步工作框架，包括（1）数据收集和分析：我们收集和分析了邻近城市的数据，并使用建模和再分析数据集。通过结合这些来源，我们的目标是重建该研究地点自 1836 年以来的历史时间序列。这个扩展的信息集增强了我们对过去风暴潮事件的理解。 （2）统计建模和预测：利用贝叶斯统计方法，将历史风暴潮数据拟合到适当的概率分布。这使我们能够对风暴潮强度进行概率预测，从而深入了解未来事件的可能性及其对沿海地区的潜在影响。 （3）敏感性分析：我们使用马尔可夫链蒙特卡罗（MCMC）方法进行敏感性实验，以确定影响风暴潮水平最有影响力的参数，例如阈值。 这一分析提高了我们对风暴潮事件的关键驱动因素及其不确定性的理解，进一步为沿海防御战略提供信息。 （4）专家判断和风险管理：实施专家判断，建立必要的安全水平来管理城市的洪水风险。这有助于确保在风险管理工作中充分考虑影响大、概率低的事件。遵循这个框架，我们可以全面了解哥本哈根南部城市化地区的风暴潮风险，并利用历史数据为海岸防御战略提供信息。这项研究强调了结合长期观测数据和专家见解的重要性，以提高沿海城市面临城市化和气候变化挑战的恢复能力。