Coastal Flood Risks Under Extreme Waves: Creating Resilience through Retrofitting - Living With Environmental Change (LWEC) - Coastal and Waterway Eng

研究的科学背景：沿海防御结构的维护给沿海社区带来了巨大的成本。例如，英国的海岸线总长度近12500公里，英格兰和威尔士44%的海岸线(苏格兰为6%)受到自然力量的保护，每年的维护费用约为3.58亿GB，总替换成本超过200亿GB。据预测，到2080年，海防开支将需要翻一番，才能维持目前的海岸线。随着工程师们努力维持传统的“硬”防御，如岩墙、盔甲或堤坝，包括重建前滨和海滩在内的“软”工程解决方案正迅速受到青睐。这项博士研究的目的是调查气候变化的影响(例如，海平面上升的综合影响，以及在已知存在知识差距的地方，现在海平面上升的影响更大)。对于典型的天然软防御，这项研究将通过一系列研究来解决对提升、波浪影响和海浪过冲的影响，例如岩石装甲护岸前的自然海滩形状优化。《国家：基础设施2014》(ICE，2014)报告称，洪水管理基础设施很少维护，需要关注。这些结构对恶劣天气事件的适应能力更为重要，因为它们保护其他基础设施网络免受灾害的影响。目前的设计指南(例如，Levee手册、CIRIA C731和EuroTop)主要集中在简单的几何硬防御配置上。在缺乏详细的数值或物理模型的情况下，对于复杂的几何形状或更软的自然防御配置，工程师们目前不得不根据当前的指导做出基本的假设。这导致在何时何地以及如何发生损害方面存在很大的不确定性。这对地方当局和社区在规划、适应和减轻灾害影响方面的信心几乎没有帮助。方法和预期结果：将选择一些不同的案例研究进行分析，同时适当考虑时间和预算限制。在不同情况下实现多样化是很重要的；为了实现不同环境中形态变化的整体图像，将根据海平面上升和风暴事件的现有预测制定不同的情景。将对所有开发的场景进行数值模拟，使用现有的模型，如用于波传播的天鹅和用于床面更新的XBeach。通过进行大量模拟，可以使用不同案例和场景之间的比较来确定每个变量的重要性和敏感度。实验室测试将用于对开发的模型进行校准和验证，在这项任务中，华威大学发挥了重要作用，因为它可以使用良好的物理模拟设施。该方法的独特性将通过整合现有的方法来提供气候变化和海平面上升问题的答案。意义：这项研究的结果有望提供洞察力，实质上填补与气候变化对碎石丘结构周围形态变化的影响相关的现有知识差距。目前，在设计和建造新的碎石丘结构时，会考虑气候变化可能导致的影响的预测。然而，现有的预测主要包括海平面上升(可靠)和热带气旋/飓风/台风强度增加(值得怀疑)。这一博士学位的成果极大地改进了设计方法，以抵御护岸和防波堤周围可能发生的形态变化，这将为子孙后代创造一个更安全的沿海环境。

Scientific context of the study: The maintenance of the coastal defence structures imposes huge costs to the coastal communities. For example, the total length of the UK's coastline is almost 12 500km, and in England & Wales 44% of the coastline is defended (6% in Scotland) against natural forces, costing approximately £358m each year to maintain, with total replacement costs in excess of £20 billion. Projections are that spending on coastal defences will need to double by 2080 to maintain the present coastline. As engineers struggle to maintain traditional 'hard' defences, such as rock walls, armour or embankments, 'soft' engineering solutions, including the recreation of foreshores and beaches, are rapidly finding favour. The intention of this PhD study is to investigate the effects of climate change (e.g. the combined effects of sea level rise and the now more where gaps in knowledge are known to exist. For typically natural soft defences, the research will address the effects on run-up, wave impact and wave over-wash through a range studies, such as natural beach shape optimization in front of rock-armoured revetments.The State of the Nation: Infrastructure 2014 (ICE, 2014) reports that Flood Management infrastructure is infrequently maintained and requires attention. The resilience of these structures to the severe weather events is more important because they protect other infrastructure networks from disasters. Current design guidance (e.g. Levee Handbook, CIRIA C731 & EurOtop) predominantly focuses on simple geometric hard defence configurations. In the absence of detailed numerical or physical models, for complex geometries or softer natural defence configurations, engineers currently have to make rudimentary assumptions from current guidance. This leads to large levels of uncertainly in where, when, and how the damages may occur. This does little for the confidence of local authorities and communities in regard to planning, adapting, and mitigating the effects of disasters.Methodology, and expected results: A number of different case studies will be selected for analysis, giving due considerations to the time and budget constraints. Achieving a good variety between cases is important; in order to achieve a holistic image of morphological changes in different environments.Different scenarios will be developed, based on the available projections for sea level rise and storm events. Numerical simulations will be conducted for all the developed scenarios, using available models such as SWAN for wave propagation and XBeach for bed updating.Comparisons between different cases and scenarios can be used to determine the significance and the sensitivity of each variable, by carrying out a number of simulations.Laboratory testing will be used for calibration and validation of the developed models, and in this task, University of Warwick plays an important role due to its availability of access for good physical modelling facilities. The uniqueness of the methodology will be achieved by integrating existing methods to provide answers to climate change and sea level rise problems.Significance: Outcomes of this study are expected to provide insights to substantially fulfil the existing knowledge gap related to the impacts of climate change on the morphological variations around rubble mound structures.Currently, the projections of possible climate change induced impacts are considered when designing and constructing new rubble mound structures. However, the available projections mainly cover the sea level rise (reliably) and the increased intensities of tropical cyclones/hurricanes/typhoons (doubtfully). The outcomes of this PhD vastly improve design methodologies to resist the probable morphological changes around the revetments and breakwaters, which will lead to the creation of a safer coastal environment for future generations.