Modelling the Erosion in the Scottish Coasts using the Process-Based Approach: Historic Validation and Projection of the Climate Change Scenarios

20%的苏格兰人口居住在距离海岸1公里的范围内，预计未来面临更高的侵蚀和洪水风险。苏格兰政府通过国家海岸变化评估项目(NCCA)评估了苏格兰海岸的侵蚀脆弱性。评估采用了海岸侵蚀敏感性模型(CESM)，这是一种基于参数的方法，根据地形、岩头高程、邻近地区、海浪暴露、海岸防御和历史沉积物供应来估计海岸线的变化。制作的国家比例尺地图显示了147个地点的历史海岸线演变，也提到了受到威胁的资产。然而，未来的预测只定位可能经历侵蚀的地点，并不一定表明这些地点正在经历或将受到侵蚀。我的博士研究旨在解决这一差距，使用基于过程的模型提供更现实的海岸线变化预测。与CESM相比，它需要更多的计算工作，但通过可视化气候变化的机制和影响海岸的人类干预使决策者受益。气候变化正在改变海平面上升、海浪气候和风暴等海况。预计未来极端事件将变得更加频繁，从而导致更大的海岸侵蚀风险。此外，海岸防御在某些情况下并没有阻止侵蚀，相反，它将威胁转移到其他地区。基于过程的模型将被用来理解这一现象。Delft3D(开源)、XBeach(开源)和UNIBEST是本研究的核心工具，是Deltares开发的著名的海岸建模工具。这些套件已经在荷兰(Sands Engine)和韩国海岸进行了测试，在长期和风暴条件下都表现良好。本研究将以一些特征鲜明的临界海岸为研究对象。对这些地区的调查不仅将阐明特定地点的海岸过程，也将为其他具有类似环境的地点提供经验教训。这一系列研究计划在三到四年内完成。第一年用于检查研究问题，与最前沿的研究人员建立合作关系，并收集相关数据。第二年和第三年的重点是验证模型，并着手预测气候变化和人类干预的影响。论文和考试将在第四年初完成。这项研究将展示苏格兰海岸在不断变化的气候和更频繁的风暴中的弹性。此外，还将为每个感兴趣的领域提出最有效的适应措施。将强调这一过程和以参数为基础的方法的优点和缺点，从而有可能在制定战略海岸线管理计划时结合起来。

Twenty percent of the Scottish population live within 1 km from the coast and in the future is expected at a higher risk of erosion and flooding. The Scottish Government have assessed the erosion vulnerability of the Scottish Coasts through the National Coastal Change Assessment project - NCCA. The assessment employed the Coastal Erosion Susceptibility Model (CESM), a parametric-based approach estimating the shoreline changes based on topography, rockhead elevation, proximity, wave exposure, coastal defence, and historic sediment supply. The produced national scale map is showing the historical shoreline evolution at 147 sites, also mentioning the assets in threat. However, the future projections are only locating the sites that can experience erosion, not necessarily indicate that the sites currently undergo or will be eroded.My doctorate research aims to address this gap, providing a more realistic shoreline change projection using the process-based model. Compare to the CESM, it requires more computational effort but benefiting the decision-maker by visualizing the mechanism of climate changes and human interventions in impacting the coast. The sea states, such as sea-level rise, wave climates, and storms are being altered by climate change. Extreme events are expected to become more frequent in the future and therefore result in a bigger risk of coastal erosion. Moreover, the coastal defence in some cases does not stop the erosion, rather it relocates the threat to other areas. The process-based model will be used to understand this phenomenon.The Delft3D (open-source), XBeach (open-source), and UNIBEST are the core tools in this research, well-known for coastal modelling develop by Deltares. These suites have been tested in the Netherlands (Sand Engine) and the Korean Coast, performing well in replicating the shoreline change both in long-term and storms condition. In this research, some critical coasts with distinctive characteristics will be taken as a study case. Investigation on these areas not only will elucidate the coastal processes at the specific sites, but also act as a rule of thumb for other sites with a similar environment.This series of research is designed to be completed in three to four years. The first year is allocated for examining the research question, building a collaboration with the forefront researcher, and collecting the relevant data. The second and third years focus on validating the model and proceeding to project the impact of climate changes and human interventions. The thesis and examination are to be finished in the early of the fourth year.This research will illustrate how resilient the Scottish Coasts in the changing climate and the more frequent storms. Also, the most effective adaptation measures will be proposed for each area of interest. The advantages and disadvantages of the process and parametric-based approach will be underlined, opening up the possibility of coupling in formulating the strategic shoreline management plans.