Effects of sea level on wave-driven inundation for reef-fringed shorelines

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。在马绍尔群岛共和国（RMI），提出了一项实地试验，以检查沿脆弱的环礁海岸线波浪驱动的沿海淹没。拟议研究的一个目标是估计由波浪变换驱动的沿海淹没（区域海平面+潮汐高度+风驱动的浪涌+波浪形成+波浪上升）。根据以往对关岛伊潘礁的研究，预计该礁上的水位将强有力地控制淹没幅度。为了评估有利于淹没的条件，海浪和水位条件将在深海用定向波浪浮标测量，并在珊瑚礁上用流速计和压力传感器测量。视频图像将用于评估湍流波孔对礁滩的穿透程度，并与高分辨率T-LiDAR调查相结合，获得海岸线位置的时间序列。将获得珊瑚礁粗糙度的估计值，以评估由于底部摩擦引起的膨胀耗散。气象传感器将用于监测当地的风和大气压力。波浪在珊瑚礁上转换的动力学将被评估并纳入一个基于可观测属性的单参数模型，该模型定义了入射波条件和珊瑚礁尺寸，并将根据观测结果评估社区模型XBeach。拟议的观测结果将指导洪水模型的开发，该模型将提供一个工具，以评估RMI和其他岛屿国家未来海平面上升情景下的沿海洪水风险。观测系统的要素以及参数化和/或数值化的淹没模型将移交给RMI内的机构，用于持续的海岸管理和评估目的。知识价值：珊瑚礁通常是岛屿海岸线的天然防波堤。然而，由于风暴波的形成而导致的水位升高，已被证明会改变边缘珊瑚礁上波浪转换的动力学。更好地了解海平面对波礁相互作用的影响是必要的，以便对礁缘岸线的海岸淹没和上升进行定量估计。本项目旨在获取和分析在大波浪事件中潮汐差较大的边缘珊瑚礁的原位测量数据，以(1)评估海平面上升对波浪转换和波浪驱动淹没动力学的影响；(2)开发环礁和珊瑚礁边缘海岸线沿海淹没的定量预测工具。更广泛的影响：该项目将提供一个预测模型，以评估马绍尔群岛和其他岛屿国家未来海平面上升情景下的沿海淹没情况。将发展向公众散发有关资料，作为太平洋岛屿海洋观测系统的一部分。观测系统的要素和数字淹没模型将移交给RMI内的机构，用于持续的海岸管理和评估目的。研究结果将通过在国际会议上的报告和在同行评议的期刊上的出版物向海洋学界通报。该合作项目将通过与SOEST研究人员和海洋基金外展专家的科学交流，为一名博士后研究员和RMI学生和技术人员提供培训。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).A field experiment is proposed to examine wave-driven coastal inundation along vulnerable atoll shorelines in the Republic of the Marshall Islands (RMI). A goal of the proposed research is to estimate coastal inundation (regional sea level + tidal height + wind-driven surge + wave setup + wave run-up) driven by wave transformations across fringing reef topography. Based on previous studies at Ipan reef, Guam, it is anticipated that water level over the reef will strongly control the inundation amplitude. To assess the conditions favorable for inundation, ocean wave and water level conditions will be measured in the deep ocean with a directional wave-rider buoy and across the reef with current meters, pressure sensors. Video imagery will be used to assess the penetration of turbulent wave bores over the reef flat, and to obtain time series of the shoreline position in conjunction with high resolution T-LiDAR surveys. Estimates of reef roughness will be obtained to assess swell dissipation due to bottom friction. Meteorological sensors will be used to monitor local wind and atmospheric pressure forcing. The dynamics of wave transformation over the reef will be assessed and incorporated into a single parametric model based on observable properties that define the incident wave conditions and reef dimensions, and the community model XBeach will be evaluated with the observations. The proposed observations will guide the development of an inundation model that will provide a tool to assess coastal inundation risk for future sea level rise scenarios at RMI and other island nations. Elements of the observing system and the parametric and/or numerical inundation model will be transferred to agencies within the RMI for ongoing coastal management and assessment purposes. Intellectual merit: Coral reefs typically act as natural breakwaters for island shorelines. Elevated water levels due to storm wave set up, however, have been shown to alter the dynamics of wave transformation on fringing reefs. A better understanding of sea level effects on wave-reef interactions is necessary to obtain quantitative estimates of coastal inundation and run up for reef fringed shorelines. This project aims to acquire and analyze in situ measurements across a fringing reef with a large tidal range during large wave events to (1) assess the effect of sea level rise on the dynamics of wave transformation and wave driven inundation and (2) develop quantitative prediction tools for coastal inundation for atolls and reef-fringed shorelines.Broader impact: This project will deliver a predictive model to assess coastal inundation for future sea level rise scenarios at RMI and other island nations. Dissemination of relevant information to the public will be developed as part the Pacific Islands Ocean Observing System (PacIOOS). Elements of the observing system and the numerical inundation model will be transferred to agencies within the RMI for ongoing coastal management and assessment purposes. Results will be communicated to the oceanographic community by presentations at international meetings and by publications in peer-reviewed journals. This collaborative project will provide training for one postdoctoral researcher and RMI students and technicians through scientific exchanges with SOEST researchers and Sea Grant outreach specialists.