Modeling Shoreline Morphological Evolution

海岸线形态演化建模

• 批准号: 1430913
• 负责人: Steve Elgar
• 金额: $ 69.5万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1430913&HistoricalAwards=false
• 关键词: Modeling; Shoreline; Morphological; Evolution

Many coastal areas are undergoing tremendous morphological change, resulting in deterioration of habitats and livelihoods, and altering the exchanges between land and ocean. For example, near Katama Bay, Martha's Vineyard, Massachussetts, sediment transport and morphological evolution is affecting water quality, oyster farms, tourism, and homes and structures. Waves from Hurricanes Irene and Sandy combined with strong currents caused 2.5 meter of erosion and accretion near Katama Inlet. In addition, the inlet is migrating hundreds of meters per year, and eventually will close until a storm again breaches the barrier beach separating the bay from the ocean. This project will use a combination of existing field observations and numerical model simulations to determine the causes of such morphological evolution. By investigating the effects of tides, waves, and currents on the dynamic coast of Martha's Vineyard, this research project will lead to an improved understanding of the processes driving shoreline evolution on ocean beaches and in or near inlets. The team will collaborate with U.S. Geological Survey scientists on model development for addressing a range of future scenarios and will work with local stake holders and managers to provide simulations and information about possible changes to the shoreline in response to different forcing and management choices, as well as to help plan for inlet closings and the associated changes in water quality and access. The project will also produce video lessons for high school students on relevant STEM topics.The study will address the hypotheses that: (i) migration of the inlet is owing to a combination of large nor'easters and hurricanes, more frequent, but more moderate wave events, and strong tidal flows, (ii) the timing of storms relative to flood and ebb flows and the storm duration are important to the morphological evolution, (iii) accretion inside the bay is caused by sand carried alongshore and subsequently transported into the inlet during flood flows, and (iv) closure of the inlet occurs when a large storm coincides with one or more spring flood tides, carrying sand into the inlet. The large morphological signal combined with existing observations of waves, currents, and the changing bathymetry make this site an ideal location to address hypotheses for shoreline morphological evolution, to calibrate, test, and improve numerical models that simulate the observed evolution, and to use models to predict future changes for different scenarios. Although this study will focus on the Martha's Vineyard site where there is substantial observational data and model infrastructure, the results will be applicable to a wide range of shoreline systems, with or without inlets. The dominant processes may differ from site to site, but the fundamental physics incorporated in the model are similar.

许多沿海地区正在经历巨大的形态变化，导致栖息地和生计的恶化，并改变了土地和海洋之间的交流。例如，在卡塔玛湾，玛莎葡萄园，马萨诸塞州，沉积物运输和形态进化附近，正在影响水质，牡蛎农场，旅游业以及房屋和结构。来自飓风艾琳（Irene）和桑迪（Sandy）的波浪与强烈的电流相结合，在卡塔玛（Katama）入口附近引起了2.5米的侵蚀和积聚。此外，入口每年迁移数百米，最终将关闭，直到风暴再次违反了将海湾与海洋分开的障碍海滩。该项目将结合现有的现场观测和数值模型模拟来确定这种形态演变的原因。通过调查潮汐，波浪和电流对玛莎葡萄园动态海岸的影响，该研究项目将提高人们对驱动海岸海滩和入口处或入口处的海岸线进化的过程的了解。该团队将与美国地质调查局科学家在模型开发方面合作，以解决一系列未来方案，并将与当地的利益持有人和经理合作，以响应不同的强迫和管理选择，以及帮助计划的进口和水质质量和接收变化，以提供有关海岸线可能更改的模拟和信息。 The project will also produce video lessons for high school students on relevant STEM topics.The study will address the hypotheses that: (i) migration of the inlet is owing to a combination of large nor'easters and hurricanes, more frequent, but more moderate wave events, and strong tidal flows, (ii) the timing of storms relative to flood and ebb flows and the storm duration are important to the morphological evolution, (iii) accretion inside the海湾是由沿岸携带的沙子引起的，随后在洪水流中运输到入口，（iv）当一场大风暴与一个或多个春季洪水潮汐重合，将沙子带入入口时，就会闭合入口。较大的形态信号与波浪，电流和不断变化的测深的现有观察结果相结合，使该地点成为解决海岸线形态演化的假设的理想位置，以校准，测试和改善数值模型，以模拟观察到的演变，并使用模型来预测不同风景的模型。尽管这项研究将重点放在有大量观察数据和模型基础架构的玛莎葡萄园站点上，但结果将适用于具有或没有入口的各种海岸线系统。主要过程的主要过程可能会有所不同，但是模型中纳入的基本物理学相似。