CAREER: Morphodynamics of Mixed-Energy Tidal Inlets: Sediment Bypassing Processes

职业：混合能量潮汐入口的形态动力学：沉积物绕过过程

• 批准号: 1554892
• 负责人: Maitane Olabarrieta Lizaso
• 金额: $ 69.42万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1554892&HistoricalAwards=false
• 关键词: CAREER; Morphodynamics; Mixed; Energy; Tidal

Human populations are strongly concentrated along the coasts, and, consequently, coastal ecosystems are some of the most impacted and altered environments worldwide. Due to increasing sea levels, storm intensities, and human activities, there is an imperative need to better understand coastal dynamics of flow, sediment transport, and changes in the shape of the coastline and the bottom (morphodynamics). In the past, there have been some attempts to better understand and predict coastline evolution of sandy beach areas. However, the morphodynamic response of estuary mouths and adjacent beaches to external forces (e.g. waves, tides, river outflows) has received less attention. Nonetheless, inlets play a key role in the wide variety of ecological, economic, and social services associated with estuaries, adjacent beaches, and back-barrier lagoons. The main research goal in this project is to improve the understanding of the processes that lead to sediment movement from the up-drift to down-drift sides of inlets (bypassing). The investigator will analyze the main processes driving the shoreward movement of sand bars over the ebb-tidal delta, how the interactions between tidal and littoral currents affect the alongshore and cross-shore sediment transport, and the morphodynamic effects of infragravity waves. The project will also integrate hands-on experiences to enhance the teaching of coastal morphodynamics. Lessons and educational material will be produced targeting secondary science teachers, and graduate students will be trained and engaged in applying a constructivist approach to learning at the high school level.Morphodynamics of mixed-energy inlets are still not fully understood due to the complex feedbacks between the highly temporally and spatially varying morphology, waves, tides, river flow, and mixing conditions. One of the key processes in inlet morphodynamics is sediment bypassing. It affects the sediment budget of the inlet and the sand supply to the inner bay, ebb-tidal delta, and adjacent beaches. The most accepted conceptual models of inlet bypassing could benefit from two improvements. First, swash bars over the ebb-tidal delta may not be transported onshore due, primarily, to wave swash. Rather, they should be primarily transported by surfzone currents. Additionally, littoral currents contribute to inlet bypassing not only in wave-dominated inlets, but also in mixed-energy inlets. How tidal and littoral currents interact and affect sediment transport along and across the inlet deserves additional studies. Infragravity waves might also play a primary role in inlet sediment transport processes. This project will combine in situ and remote field observations and numerical modeling at Matanzas Inlet (FL) to analyze, test and integrate these processes to improve our knowledge of sediment transport processes in mixed-energy inlets. Findings generated from this study will help us better understand the dynamics of these coastal systems and will contribute to the improvement of coastal management tools and procedures. Research and education will be fostered through the involvement of the graduate students in the PI's research group in the educational activities. In collaboration with the Center for Precollegiate Education and Training at the University of Florida, the team will develop and implement four 5E lessons geared towards high-school students and secondary science teachers. This collaboration will provide the graduate students with the opportunity to be trained in the application of the 5E instructional method at the high-school level. A curricular module for a Summer Institute course directed towards secondary science teachers will also be developed as part of this project. The direct interaction with teachers through this collaborative initiative will promote the inclusion of key concepts of coastal morphodynamics (beach, estuaries, and inlets) into the K-12 science curriculum.

人口沿着海岸高度集中，因此，沿海生态系统是全世界受影响和改变最严重的环境之一。由于海平面上升，风暴强度和人类活动，迫切需要更好地了解流动，沉积物运输，以及海岸线和底部形状的变化（形态动力学）的沿海动态。 在过去，有一些尝试，以更好地了解和预测桑迪海滩地区的海岸线演变。然而，河口和邻近海滩的外部力量（如波浪，潮汐，河流流出）的形态动力学响应受到较少的关注。尽管如此，在与河口、邻近海滩和后障泻湖相关的各种生态、经济和社会服务中，入口发挥着关键作用。该项目的主要研究目标是提高对导致泥沙从进口上游侧向下游侧运动（旁路）的过程的理解。研究者将分析潮落三角洲上沙坝向岸运动的主要过程，潮汐和沿岸的流之间的相互作用如何影响沿岸和跨岸沉积物输运，以及亚重力波的形态动力学效应。该项目还将结合实践经验，以加强海岸形态动力学的教学。课程和教育材料将针对中学科学教师，研究生将接受培训，并参与应用建构主义的方法来学习在高中一级。形态动力学的混合能源入口仍然没有完全理解，由于高度的时间和空间变化的形态，波浪，潮汐，河流流量和混合条件之间的复杂反馈。泥沙绕流是进口水流动力学的关键过程之一。它影响了河口的泥沙收支以及对内湾、落潮三角洲和邻近海滩的供沙。最被接受的进气道旁路概念模型可以从两个改进中受益。首先，落潮三角洲上的冲沙坝可能不会被输送到岸上，主要是由于波浪冲沙。相反，它们应该主要通过冲浪带洋流运输。此外，沿岸的流不仅在波控进气道中，而且在混合能进气道中有助于进气道旁路。潮汐流和沿岸的流如何相互作用并影响沿着和穿过入口的泥沙输运，值得进一步研究。重力波在河口泥沙输移过程中也起主要作用。该项目将结合联合收割机在马坦萨斯进口（FL）的现场和远程现场观测和数值模拟，分析，测试和整合这些过程，以提高我们的混合能源进口泥沙输运过程的知识。 这项研究的结果将有助于我们更好地了解这些沿海系统的动态，并将有助于改进沿海管理工具和程序。研究和教育将通过研究生参与PI研究小组的教育活动来促进。该团队将与佛罗里达大学的大学前教育和培训中心合作，开发和实施四门面向高中学生和中学科学教师的5E课程。这项合作将为研究生提供在高中阶段应用5E教学方法的培训机会。作为该项目的一部分，还将为针对中学科学教师的暑期研究所课程编制一个课程模块。通过这一合作举措与教师的直接互动将促进纳入K-12科学课程的沿海形态动力学（海滩，河口和入口）的关键概念。