SIGNATURES OF RESILIENCE IN HUMAN-ALTERED COASTAL SYSTEMS

人类改变的沿海系统的恢复力特征

• 批准号: NE/X011496/1
• 负责人: Eli Lazarus
• 金额: $ 10.31万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX011496%2F1
• 关键词: SIGNATURES; RESILIENCE; HUMAN; ALTERED; COASTAL

More than 85% of the world's coastline has been somehow altered by human activities. These activities and their consequences are concentrated in the Low Elevation Coastal Zone: a ribbon of coastal land below 10 m elevation that hosts as many as 1 billion people and a disproportionate share of the planet's physical infrastructure. Such pronounced exposure of people and infrastructure along low-lying coastlines means that these environments sustain severe impacts from coastal hazards (e.g., erosion, storm surge, flooding, sea-level rise). Moreover, population growth, infrastructural expansion, and climate change only make hazard impacts worse.As coastal risk - defined as the exposure of people and infrastructure to natural hazards - has increased, so has broad scientific interest in coastal resilience, as an alternative to conventional engineering approaches to protecting human-altered coastlines from natural hazards.Here, coastal resilience is defined as how a coastal system - the physical, ecological, and human components of a coastal environment, and the relationships among those components that sustain their functioning - recovers from disturbances, like extreme storms, over time. At the seaward edge of the Low Elevation Coastal Zone, environments characterised by beaches, dunes, floodplains, and wetlands take their physical shape from the storm events that they absorb. Despite their precarity to natural hazards, many low-lying coastlines are extensively built upon and intensively altered by human activities. However, human-altered coastlines are almost never examined as dynamic environments in their own right.Understanding human-altered coastlines as dynamic systems is essential to predicting hazard impacts, anticipating effects of climate change, and reducing coastal risk. Previous work has used computer modelling to suggest that unlike their natural counterparts, human-altered coastlines evolve over time to become increasingly vulnerable to storm damage and functionally dependent on engineered hazard defences - thus rendering them less resilient than natural barriers. But that difference in how human-altered and natural coastlines evolve, and what that means for their resilience, has not yet been demonstrated and examined with observations and measurements from real places. This project addresses that gap, by testing theory with empirical evidence.The aim of this project is to identify and measure indicators of resilience in human-altered and natural low-lying coastal settings around the world - all at the exposed, seaward edge of the Low Elevation Coastal Zone - using new methods for analysing decades of satellite imagery. I will measure the physical "signatures" that distinguish human-altered from natural coastlines, relate those physical signatures to patterns of coastal development over time, and combine that information to determine the relative "stability" of these human-altered versus natural coastal settings. This project will be first to quantify coastal resilience this way, and at this scale, derived entirely from observational data from real settings.Overall, with its focus on human-altered coastlines and its novel analytical approach, this project will deliver new, observation-driven insights into resilience in vulnerable low-lying coastal environments worldwide. The methods and findings that emerge from this project will enable future interdisciplinary research into how coastal resilience could be deliberately enhanced in targeted, efficient, effective ways to reduce coastal risk.

世界上超过 85% 的海岸线已因人类活动而发生某种程度的改变。这些活动及其后果集中在低海拔沿海地区：海拔低于 10 m 的沿海地带，居住着多达 10 亿人口，在地球上的物质基础设施中占有不成比例的份额。低洼海岸线的人员和基础设施暴露如此明显，意味着这些环境承受着沿海灾害（例如侵蚀、风暴潮、洪水、海平面上升）的严重影响。此外，人口增长、基础设施扩张和气候变化只会使灾害影响变得更严重。随着沿海风险（定义为人类和基础设施面临自然灾害的风险）增加，人们对沿海复原力的科学兴趣也随之增加，作为保护人类改变的海岸线免受自然灾害影响的传统工程方法的替代方案。这里，沿海复原力被定义为沿海系统如何（物理、生态和人类） 沿海环境的组成部分，以及维持其功能的这些组成部分之间的关系，会随着时间的推移从极端风暴等干扰中恢复。在低海拔沿海地区的临海边缘，以海滩、沙丘、洪泛区和湿地为特征的环境因其吸收的风暴事件而形成其物理形状。尽管面临自然灾害的风险很大，但许多低洼海岸线都是在人类活动的基础上广泛修建和强烈改变的。然而，人类改变的海岸线本身几乎从未被视为动态环境。将人类改变的海岸线理解为动态系统对于预测灾害影响、预测气候变化的影响和减少沿海风险至关重要。先前的研究使用计算机建模表明，与自然海岸线不同，人类改变的海岸线随着时间的推移而演变，变得越来越容易受到风暴破坏，并且在功能上依赖于工程灾害防御——从而使它们的弹性不如自然屏障。但人类改变的海岸线和自然海岸线如何演变的差异，以及这对它们的恢复力意味着什么，尚未通过实际地点的观察和测量得到证明和检验。该项目通过用经验证据检验理论来解决这一差距。该项目的目的是使用分析数十年卫星图像的新方法，识别和测量世界各地人类改变的自然低洼沿海环境的复原力指标——所有这些都位于低海拔沿海地区暴露的临海边缘。我将测量区分人类改变的海岸线和自然海岸线的物理“特征”，将这些物理特征与海岸线随时间的发展模式联系起来，并结合这些信息来确定这些人类改变的海岸线与自然海岸线的相对“稳定性”。该项目将首次以这种方式量化沿海恢复力，并且在这种规模上完全来自真实环境的观测数据。总体而言，该项目重点关注人类改变的海岸线和新颖的分析方法，将为全球脆弱的低洼沿海环境的恢复力提供新的、以观测为导向的见解。该项目的方法和发现将使未来的跨学科研究能够以有针对性、高效、有效的方式有意识地增强沿海复原力，以减少沿海风险。