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

基本信息

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

项目摘要

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.

沿海沼泽可以减弱风暴潮和海浪，保护生命和财产。这种绿色基础设施还改善了水质，并为经济上重要的渔业提供了栖息地。同样，洪泛区植被可以减少洪峰，增强河岸稳定性，并减少河道的养分负荷。由于这些好处，资源管理者提倡对河流廊道和沿海地区的植被景观进行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。恢复工作包括重建植被和将沉积物转移到侵蚀区域，需要对植被区域的沉积物输送和滞留有基本的了解，而本项目将有助于提供这种了解。除了这项研究可能产生的这些期望的社会效益外，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初中和高中进行推广。该研究项目将开发以下物理预测：沉积物输送作为流量和植被特征的函数。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，这将有助于了解河道内植被的几何形状和分布如何影响速度、湍流和沉积物输送。实验将记录速度和河道规模的沉积物通量，并将使用激光扫描来跟踪水深演变。通过与美国垦务局的合作，将促进新模型在全面恢复项目中的实际应用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。