CAREER: The influence of turbulence to mass transport in complex aquatic habitats

在沿海地区，经济和生态系统的复原力密切相关，在那里，发展和水文灾害（风暴潮、洪水、侵蚀）正在加剧。人们越来越多地寻求在水体附近采取基于生态系统的保护措施，如活海岸线、牡蛎礁和红树林，以增强对这些气候灾害的抵御能力;然而，恢复项目和基于生态系统的防御措施往往失败，因为目前对侵蚀和沉积物迁移的理解是基于无植被渠道的简化模型。这项研究将开发新的科学知识，以阐明三维冠层（牡蛎礁，海草床，红树林）对湍流，沉积物运动和蓝碳（泥炭沉积物）封存的影响。使用实验室水槽和现场实验，PI将在这些复杂的自然栖息地内测试新的泥沙输运理论。更好地了解植被河岸和海岸线侵蚀过程的社会效益是巨大的，并可转移到世界各地的水生系统，使脆弱地区的管理人员能够规划有影响力的恢复项目和管理战略，以减轻洪水，河岸侵蚀或海平面上升的影响。该项目将通过将研究和实地学习与各种教育水平的课堂教学相结合，包括初中/高中，本科和研究生以及专业人士，让不同的学生参与水生系统的体验式“靴子在泥中”研究。在实地研究区的一个岛上的生活生态水力学实验室是下一代学生科学家将在生态学和工程学的交叉点进行培训的地方。这项研究将发展和测试尖端的泥沙输运理论，阐明剪切应力和湍流对不同，复杂的水生栖息地内的质量运输的作用。在实地，PI将测试1）牡蛎淹没的刚性树冠，2）海草淹没的柔性树冠，和3）红树林的新兴树冠的水动力和泥沙输运效果。这些功能不同的冠层类型内的质量传输将通过场耦合实验室实验与湍流。更好地了解剪切应力湍流关系的泥沙输运在不同的冠层类型和流态将从根本上改变的方式，泥沙输运模拟在复杂的冠层，并将显着提高预测能力，在自然水体中的侵蚀和沉积过程。 对沉积物迁移的新认识将与其在生态系统恢复和基于自然的基础设施设计方面的应用联系起来，以促进对气候灾害的更大复原力。教育活动包括建立一个岛屿生活生态水力学实验室，吸引1 400多名学习者，并在项目期间让250名学生进入水生研究地点。综合研究教育领域的经验是针对有影响力的学术阶段，包括初中科学研究计划和夏令营，以吸引和留住那些可能没有选择干职业的学生。在高流量社区空间展示初中和高中研究项目将有效地吸引社区成员参与研究。该奖项反映了NSF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。

Economic and ecosystem resilience are closely connected in coastal regions, where development as well as hydrologic hazards (storm surge, flooding, erosion) are intensifying. Ecosystem-based protections near waterbodies, such as living shorelines, oyster reef and mangrove forest, are increasingly sought to enhance resilience to these climatic hazards; however, restoration projects and ecosystem-based defenses often fail because current understanding of erosion and sediment transport is based on simplified models of non-vegetated channels. This research will develop new scientific knowledge to illuminate effects of three-dimensional canopies (oyster reefs, seagrass beds, mangroves) on turbulent flow, movement of sediments, and sequestration of Blue Carbon (peat deposits). Using both laboratory flume and field experiments, the PI will test novel sediment transport theory within these complex natural habitats. Societal benefits of better understanding of erosional processes at vegetated river banks and shorelines are vast and transferable to aquatic systems around the world, allowing managers of vulnerable areas to plan impactful restoration projects and management strategies to mitigate effects of flooding, bank erosion, or sea level rise. The project will engage diverse students in an experiential ‘boots in-the-mud’ study of aquatic systems by integrating research and field-based learning with classroom instruction at a variety of educational levels, including middle/high school, undergraduate, and graduate students, and professionals. A Living Ecohydraulics Laboratory on an island in the field study area is where the next generation of student scientists will be trained at the intersection of ecology and engineering. This research will develop and test cutting-edge sediment transport theory, elucidating the roles of shear stress and turbulence on mass transport within diverse, complex aquatic habitats. In the field, the PI will test the hydrodynamic and sediment transport effects of 1) submerged, rigid canopies of oyster, 2) submerged, flexible canopies of seagrasses, and 3) emergent canopies of mangrove. Mass transport within these functionally diverse canopy types will be related to turbulence through field-coupled laboratory experimentation. Better understanding of shear stress-turbulence relationships for sediment transport across varied canopy types and flow regimes will fundamentally change the way that sediment transport is modeled in complex canopies and will significantly advance predictive ability regarding erosional and depositional processes in natural waterbodies. Newly-developed sediment transport understanding will be linked to its applications in ecosystem restoration and design of nature-based infrastructure to promote greater resilience to climatic hazards. Educational activities include establishment of an island Living Ecohydraulics Laboratory to engage over 1400 learners and immerse 250 students into aquatic research sites over the life of the project. The integrated research-educational field experiences are targeted at influential academic stages, including middle-high school science research programs and summer camps, to attract and retain students who may have otherwise not chosen STEM careers. Display of middle and high school research projects in high-traffic community spaces will effectively engage community members in the research.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.