Impact of vegetation geometry and distribution on bedload transport

植被几何形状和分布对底质输送的影响

• 批准号: 1854564
• 负责人: Heidi Nepf
• 金额: $ 40.78万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1854564&HistoricalAwards=false
• 关键词: Impact; vegetation; geometry; distribution; bedload; Impact; vegetation; geometry; distribution; bedload

Coastal marshes attenuate storm surge and waves, protecting life and property. This green infrastructure also improves water quality and provides habitat for economically important fisheries. Similarly, floodplain vegetation reduces flood peaks, enhances bank stability, and reduces nutrient loading to river channels. Because of these benefits, resource managers advocate the replanting and ecological management of vegetated landscapes along river corridors and in coastal zones. The US spends billions of dollars each year to restore these landscapes. The restoration efforts, which include the re-establishment of vegetation and the diversion of sediment into eroded areas, require a fundamental understanding of sediment transport and retention in vegetated regions that this project will help provide. In addition to these desired societal benefits that could stem from this research, the project will also train one doctoral student, support one undergraduate student each summer, and include outreach in Boston-area middle and high schools.This research project will develop physical predictions of sediment transport as a function of flow and vegetation characteristics. The new models will be developed through a series of laboratory experiments using model vegetation of increasing complexity that will build an understanding of how vegetation geometry and distribution within a channel impact velocity, turbulence, and sediment transport. Experiments will record velocity and channel-scale sediment flux, and will use laser-scans to track bathymetric evolution. The transfer of new models to practical application in the full-scale restoration projects will be facilitated through collaboration with the US Bureau of Reclamation.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.

沿海沼泽减弱了风暴潮和海浪，保护生命和财产。这种绿色基础设施还提高了水质，并为经济上重要的渔业提供了栖息地。同样，洪泛区植被减少了洪水峰，增强了银行的稳定性，并减少了对河道的营养负荷。由于这些好处，资源经理主张沿河走廊和沿海地区的植被景观的重新种植和生态管理。美国每年花费数十亿美元来恢复这些景观。恢复工作包括重新建立植被以及将沉积物转移到侵蚀地区，需要对该项目将有助于提供的植被区域的沉积物运输和保留。除了这项研究可能引起的这些期望的社会福利外，该项目还将培训一名博士生，每年夏天支持一名本科生，并包括在波士顿地区的中学和高中进行外展。这项研究项目将根据流量和植被特征来开发对沉积物运输的物理预测。新模型将通过一系列实验室实验开发，使用越来越复杂的模型植被，这将建立对通道内植被的几何形状和分布如何影响速度，湍流和沉积物传输的理解。实验将记录速度和通道尺度的沉积物通量，并将使用激光扫描来跟踪测深的演化。将新模型转移到全尺度修复项目中的实际应用中，将通过与美国填海局的合作进行促进。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子的智力优点和更广泛影响的审查标准来评估值得支持的。