| Abstract: | Tidal mass exchange between a submersed aquatic vegetation (SAV) bed and the main channel of the Potomac River was investigated. Water levels were recorded at 5 minute intervals from August (when plants were present) through December (when plants were absent). Velocities were measured during individual tidal cycles both in the presence and absence of plants. Flow patterns were found to be altered significantly when plants were present. SAV impeded flow onto the shoal causing a water level phase lag between the bed and the channel, a reduction in flow speed and a change in flow direction. The phase lag was enhanced when the low frequency (subtidal) water level in the channel was below normal. The phase lag was further enhanced during spring tides. Ebb flow in the presence of plants was perpendicular to the edge of the SAV bed in the direction of the pressure gradient established by the lagging water level. Flood flow did not follow such a predictable pattern despite the strongest pressure gradients occurring during flood tides. In the absence of plants the flow speed increased by nearly an order of magnitude and the water-level phase lag disappeared. |
| Genre: | Conference Paper |
| ProdID: | 70016935 |
| Citation Author: | Jenter, Harry, L.; Rybicki, Nancy, B.; Baltzer, Robert, A.; Carter, Virginia |
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| Citation Editor: | Shane Richard M. |
| Citation End Page: | 304 |
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| Citation Language: | English |
| Citation Larger Work Title: | Proceedings - National Conference on Hydraulic Engineering |
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| Citation Number Of Pages: | 7 |
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| Citation Publisher: | Publ by ASCE |
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| Citation Search Results Text: | Tidal mass exchange between a submersed aquatic vegetation bed and the main channel of the Potomac River; 1991; Conference Paper; Proceedings - National Conference on Hydraulic Engineering; Jenter, Harry, L.; Rybicki, Nancy, B.; Baltzer, Robert, A.; Carter, Virginia |
| Citation Start Page: | 298 |
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| Citation Year: | 1991 |
| Type: | citation/reference |
| Text: | Tidal mass exchange between a submersed aquatic vegetation bed and the main channel of the Potomac River; 1991; Conference Paper; Proceedings - National Conference on Hydraulic Engineering; Jenter, Harry, L.; Rybicki, Nancy, B.; Baltzer, Robert, A.; Carter, Virginia |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1991 00:00 -0600 |
| Publisher: | Publ by ASCE |
