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

极端波浪下的沿海洪水风险：通过改造创造抵御能力 - 与环境变化共存 (LWEC) - 沿海和水道工程

• 批准号: 1924369
• 金额: --
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1924369
• 关键词: Coastal; Flood; Risks; Under; Extreme

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.

研究的科学背景：维护海岸防御结构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，在英格兰和威尔士，44%的海岸线（苏格兰为6%）受到自然力量的保护，每年维护成本约为3.58亿英镑，总重置成本超过200亿英镑。预计到2080年，海岸防御支出将需要翻一番，以维持目前的海岸线。当工程师们努力维护传统的“硬”防御时，如岩壁、装甲或防护墙，“软”工程解决方案，包括对前滩和海滩的改造，正在迅速受到青睐。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，现在更多的知识差距是已知存在的。对于典型的天然软防御，研究将通过一系列研究来解决对助跑、波浪冲击和波浪过冲的影响，例如岩石装甲护岸前的天然海滩形状优化。国家状况：基础设施2014（ICE，2014）报告称，洪水管理基础设施很少维护，需要注意。这些结构对恶劣天气事件的复原力更为重要，因为它们可以保护其他基础设施网络免受灾害。目前的设计指南（如《堤坝手册》、CIRIA C731和EurOtop）主要侧重于简单的几何硬防御配置。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较软的自然防御配置，工程师目前必须根据当前的指导进行基本假设。这导致了很大程度的不确定性，在哪里，何时以及如何损害可能发生。这无助于增强地方当局和社区对规划、适应和减轻灾害影响的信心。方法和预期结果：将选择一些不同的案例研究进行分析，同时适当考虑到时间和预算的限制。为了对不同环境的形态变化有一个全面的了解，必须在各种情况之间取得良好的差异，将根据对海平面上升和风暴事件的现有预测，制定不同的设想。将对所有开发的方案进行数值模拟，使用现有的模型，如用于波浪传播的SWAN和用于床更新的XBeach。通过进行一些模拟，可以使用不同情况和方案之间的比较来确定每个变量的重要性和敏感性。将使用实验室测试来校准和验证开发的模型，在这项任务中，沃里克大学发挥了重要作用，因为它的访问良好的物理建模设施的可用性。该方法的独特性将通过整合现有方法来实现，以提供气候变化和海平面上升问题的答案。这项研究的结果预计将提供深刻的见解，以充分满足现有的知识差距有关的影响，气候变化对周围的形态变化碎石丘结构。在设计和建造新的碎石堆结构时，考虑到对气候变化可能引起的影响的预测。然而，现有的预测主要涵盖海平面上升（可靠）和热带气旋/飓风/台风强度增加（可疑）。这个博士学位的成果大大改善了设计方法，以抵御护岸和防波堤周围可能的形态变化，这将导致为子孙后代创造一个更安全的沿海环境。