PREEVENTS Track 2: Collaborative Research: Geomorphic Versus Climatic Drivers of Changing Coastal Flood Risk

沿海洪水是人类社会面临的最危险、最具破坏性的自然灾害之一，沿海发展和气候变化正在导致脆弱性急剧上升。自19世纪以来，河口航道通常被加深和拓宽了两到三倍，港口入口被加深和流线型，很大一部分湿地被填满，取而代之的是社区。这种地貌变化降低了自然对风暴潮和潮汐的抵抗力，从而增加了洪水的风险。同样，海平面上升和风暴特征（如强度、大小和路径）的气候调节变化也会改变洪水风险。拟议研究项目的总体目标是揭示和对比这些地貌和气候变化改变洪水风险的机制。这一目标将通过结合计算建模、历史气候和风暴潮数据分析以及基于理论的综合来实现。这项研究将为一名博士后研究助理和几名研究生和本科生，包括代表性不足的群体提供支持。它将通过突出可能加剧沿海洪水的沿海发展做法，改善城市化港口和河口内社区的福祉。该项目计划提高了科学素养和参与度，并通过与当地利益相关者和政府以及美国地质调查局和美国陆军工程兵团的互动，将研究与应用联系起来。该项目将通过一些新颖的研究和技术创新来提高对沿海洪水中气候和地貌因素的理解和分离。研究人员将使用一个独特的潮汐测量数据集，该数据集可以追溯到19世纪，并结合当代、回顾性和理想化的水动力模型来阐明系统的敏感性。众所周知，对潮汐动力学的简化见解将在风暴潮中进行测试，然后用于帮助解释当地地形，水深和湿地面积的变化如何改变了摩擦阻尼和长波力学。对气候、风暴特征和形态变化的综合分析将确定气候变率和水深变化调节风暴潮的模式和途径。将开发和采用先进的非平稳单变量和多变量统计模型来纳入这些变化，并评估与沿海设计和风险评估相关的统计特性如何作出反应。一个洪水模型比较研讨会将有助于量化相关模型的敏感性，这将有助于改善学术和业务预测界的河口和洪泛平原预测。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Coastal flooding is one of the most dangerous and damaging natural hazards that societies face, and coastal development and climate change are causing a dramatic rise in vulnerability. Since the 19th century, estuary channels have typically been deepened and widened by a factor of two or three, harbor entrances have been deepened and streamlined, and a large proportion of wetlands have been filled over and replaced with neighborhoods. Such geomorphic changes increase flood risk by reducing natural resistance to storm surge and tides. Similarly, sea level rise and climate-modulated variations in storm characteristics such as intensity, size and track path also alter flood risk. The overarching goal of the proposed research project is to reveal and contrast the mechanisms by which these geomorphic and climatic changes alter flood risk. This goal will be met using a combination of computational modeling, historical climate and storm surge data analysis, and theory-based synthesis. The study will provide support for a postdoctoral research associate and several graduate students and undergraduates, including underrepresented groups. It will improve the well-being of communities within urbanized harbors and estuaries by highlighting coastal development practices that can worsen coastal flooding. The project plan increases scientific literacy and engagement, and connects the research to applications through interactions with local stakeholders and governments, as well as the US Geological Survey and the US Army Corps of Engineers.The project will improve the understanding and separation of climatic and geomorphic factors in coastal flooding through several elements of novel research and technical innovation. The investigators will use a unique tide-gauge data set that extends back to the 19th century together with contemporary, retrospective, and idealized hydrodynamic models to elucidate system sensitivities. Well-known, simplified insights into tidal dynamics will be tested for storm surge, then used to help interpret how altered local topography, bathymetry and wetland area have changed frictional damping and long-wave mechanics. A combined analysis of climate, storm characteristics, and morphologic change will identify the modes and pathways through which climate variability and bathymetric change modulate storms surges. Advanced non-stationary univariate and multivariate statistical models will be developed and employed to incorporate these changes and assess how statistical properties relevant for coastal design and risk assessments respond. A flood model inter-comparison workshop will help quantify relevant modeling sensitivities, which will help to improve estuary and floodplain predictions for the academic and operational forecasting community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.