Feedbacks between plants, flow, and particle fate
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016.
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| Format: | Thèse |
| Langue: | eng |
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Massachusetts Institute of Technology
2016
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| Accès en ligne: | http://hdl.handle.net/1721.1/104199 |
| _version_ | 1826214139171700736 |
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| author | Follett, Elizabeth (Elizabeth Marie) |
| author2 | Heidi M. Nepf. |
| author_facet | Heidi M. Nepf. Follett, Elizabeth (Elizabeth Marie) |
| author_sort | Follett, Elizabeth (Elizabeth Marie) |
| collection | MIT |
| description | Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016. |
| first_indexed | 2024-09-23T16:00:26Z |
| format | Thesis |
| id | mit-1721.1/104199 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T16:00:26Z |
| publishDate | 2016 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1041992019-04-12T16:10:10Z Feedbacks between plants, flow, and particle fate Follett, Elizabeth (Elizabeth Marie) Heidi M. Nepf. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering. Civil and Environmental Engineering. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016. Cataloged from PDF version of thesis. Includes bibliographical references. Environmental flows carry a wide variety of particles that interact with vegetation. Vegetated canopies are anchored by sediment, release pollen and seeds to colonize new ground, rely on nutrients carried by sediment, and may be killed by disease spores. While the influence of vegetation on flow profiles has been investigated, the transport of particles within vegetated canopies remains poorly understood. In this thesis I present the results from laboratory experiments and numerical modeling that investigated particle fate and transport around emergent and submerged model vegetation canopies. The effect of canopy mediated flow on particle transport was explored in experimental studies using model vegetation. First, the flow diversion and extended wake region due to a circular patch of model reedy emergent vegetation resulted in regions of scour on the patch side and deposition in the patch wake, which are related to a non-dimensional flow blockage parameter. In-patch scour increased with turbulent kinetic energy levels, which were positively correlated to stem density. Second, within a long, submerged canopy, the capture of particles was reduced near the leading edge due to the presence of a vertical updraft. In the fully developed region, particle capture was increased for releases below the penetration of canopy scale vortices, and for particles with increased settling velocity. The impact of canopy flexibility on turbulence within the canopy was explored using a submerged canopy of model flexible vegetation. The drag reduction due to reconfiguration was described through a drag coefficient that decreased as a power-law function of velocity, with a negative exponent (Vogel number). Velocity measurements made within and above the canopy demonstrate that unsteady reconfiguration, responding to individual turbulent events, preferentially allows stronger sweeps to penetrate the canopy, enhancing the skewness. Next, spore escape was investigated across a range of canopy densities and particle settling velocities using a random displacement model (RDM) parameterized with an eddy diffusivity based on a simple set of physical parameters. This work filled a gap between field observations and traditional Lagrangian stochastic modeling, improving predictions of fungal spore escape to drive long range transport models. The effect of canopy and particle characteristics on the genotypic diversity of Zostera marina canopies was explored, pointing to the physical mechanisms governing successful pollination. by Elizabeth M. Follett. Ph. D. 2016-09-13T19:11:31Z 2016-09-13T19:11:31Z 2016 2016 Thesis http://hdl.handle.net/1721.1/104199 958137552 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 115 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Civil and Environmental Engineering. Follett, Elizabeth (Elizabeth Marie) Feedbacks between plants, flow, and particle fate |
| title | Feedbacks between plants, flow, and particle fate |
| title_full | Feedbacks between plants, flow, and particle fate |
| title_fullStr | Feedbacks between plants, flow, and particle fate |
| title_full_unstemmed | Feedbacks between plants, flow, and particle fate |
| title_short | Feedbacks between plants, flow, and particle fate |
| title_sort | feedbacks between plants flow and particle fate |
| topic | Civil and Environmental Engineering. |
| url | http://hdl.handle.net/1721.1/104199 |
| work_keys_str_mv | AT follettelizabethelizabethmarie feedbacksbetweenplantsflowandparticlefate |