Collaborative Research: An Efficient Computational Approach for Wave and Surge Attenuation in Wetlands and Applications in Flood Risk Reduction

这一建议开发了一个准确和有效的方法来模拟流体的相互作用与许多灵活的植物茎（建模为可弯曲的圆柱体）在很宽的雷诺数范围。研究活动包括推导底部固定和可弯曲圆柱的核函数的新数学，验证和确认模型输出，调查拖曳力和弯曲角度之间的关系以及圆柱群中的侧向间隙与波浪和浪涌衰减的有效性之间的联系，并扩大模型的规模，以推断大规模模拟的宏观参数，以测试湿地恢复力和洪水风险降低的假设。三个教育项目：暑期外展、少数民族实习和研究生交流为社区和少数民族提供了参与研究和大学间合作的机会。持续的气候变化和海平面上升对全球沿海栖息地和社区构成了重大威胁。海平面上升的影响导致海岸侵蚀和洪水增加。例如，由于地面沉降、海平面上升和人类干预，密西西比河三角洲和路易斯安那州海岸每24分钟就损失一英亩湿地，占美国大陆沿海湿地年损失总量的80%。路易斯安那州南部湿地的长期丧失大大削弱了对卡特里娜飓风和丽塔飓风（2005年）等灾难性洪水的自然防御。飓风过后的几个月里，有1 500多人丧生，几个主要的沿海人口受到重创。减轻洪水破坏和减少风暴潮的威胁势在必行。湿地植被可以有效地降低水流流速，这已被公认。从拟议的研究结果将不仅为沿海工程师和管理人员在沿海湿地的波浪和浪涌衰减的洞察力，但也作为有用的参考，机械，土木，环境和海洋工程的流体与结构和植物冠层的相互作用。开发的模拟工具将有利于社会更好地保护沿海生态系统免受风暴和海平面上升的影响，并减少洪水的风险。从研究中获得的知识将在多渠道教育中吸收，以培养两名研究生，使少数民族参与数学科学，并激发社区对计算数学的兴趣。该项目将教育公众关于路易斯安那州沿海洪水和侵蚀的严重性。

This proposal develops an accurate and efficient method for modeling the interaction of fluid with numerous flexible plant stems (modeled as bendable cylinders) at a wide range of Reynolds numbers. Research activities include deriving new mathematics of kernel functions for bottom-clamped and bendable cylinders, verifying and validating model output, investigating the relation between the drag force and the bending angle and the link between the lateral clearance in a cylinder cluster and the effectiveness of wave and surge attenuation, and upscaling the model to infer macroscale parameters for large-scale simulations to test hypotheses of wetland resilience and flood risk reduction. Three educational programs: Summer Outreach, Minority Internship, and Graduate Student Exchange, provide opportunities for communities and minorities to participate in research and inter-university collaborations.Continued climate change and sea level rise pose a major threat to coastal habitats and communities worldwide. The impact of sea level rise has caused increased coastal erosion and flooding. For example, owing to subsidence, sea level rise and human interventions, the Mississippi River Delta and the Louisiana coast lose one acre of wetland every 24 minutes, which accounts for 80% of the total annual loss of coastal wetlands in the continental United States. The chronic wetland loss in south Louisiana has considerably weakened the natural defense against catastrophic floods, such as Hurricanes Katrina and Rita (2005). Over 1,500 people lost their lives and several major coastal populations were crippled for months after the hurricanes passed. Mitigating flood damage and reducing the threat of storm surges are imperative. It has been recognized that vegetation in wetlands can effectively reduce the flow speed. Results from the proposed research will not only provide insight to wave and surge attenuation in coastal wet-lands for coastal engineers and managers, but also serve as useful references for mechanical, civil, environmental, and ocean engineering concerning interactions of fluid with structures and plant canopies. The developed simulation tools will benefit society in better protecting the coastal ecosystem from impacts of storms and sea level rise and reducing the risk of flooding. Knowledge gained from the research will be assimilated in multi-channel education to train two graduate students, to involve minorities in mathematical science, and to stimulate the interest of communities in computational mathematics. This project will educate the public about the gravity of coastal flooding and erosion in Louisiana.