Vertical structure of fluid velocity for flow through vegetation under waves
Abstract
Interaction between hydrodynamics (e.g., wave attenuation, fluid flow characteristics) and vegetation in coastal area is very important to develop strategies for maintenance of sustainable ecological systems. However, there are several difficulties in collecting and analyzing field data of wave attenuation and fluid flow characteristics in coastal vegetation owing to complexity of the various physical processes, such as changes in wind speed and direction, tides, wave refraction and shoaling. Furthermore, without understanding the impact of waves on real vegetation, it is difficult to develop scale-model tests. Therefore, a controlled laboratory environment at prototype scale with live plants is recommended to quantify the hydrodynamics and responses of vegetation. To account for this, a large-scale laboratory experiment was conducted during the summer of 2010 at the Large Wave Flume (104m long, 3.6m wide, and 4.6m deep) at O.H. Hinsdale Wave Research Laboratory (HWRL) at Oregon State University. Live plants (Schoenoplectus pungens or threesquare bulrush) were collected from the field (Tillamook, Oregon), and transplanted to twelve 8-ft long planters. The planters were placed into 4 channels with different plant densities. To our knowledge, this is the first test using live plants in a controlled, high energy wave environment. Observations of hydrodynamics under regular waves will be presented with an emphasis on the vertical structures of fluid velocity with different plant densities. The velocity data were measured using Acoustic Doppler Velocimeters (ADVs) and decomposed into mean current, wave-induced velocity and turbulence. Finally, the effect of the vegetation on the vertical structures of fluid velocity will be discussed. It is acknowledged that this work was conducted as part of Ecological modeling of emergent vegetation for sustaining wetlands in high wave energy coastal environments (NSF 0828549).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMOS54A..02Y
- Keywords:
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- 4217 OCEANOGRAPHY: GENERAL / Coastal processes;
- 4546 OCEANOGRAPHY: PHYSICAL / Nearshore processes