Impact of exchange flows on wetland flushing
The flushing of littoral regions is governed by barotropic river flows, QR, and baroclinic exchange flows, ΔQ. This note presents field observations of two different flushing regimes in a shallow wetland that borders a lake. In spring, when river flows are high, the wetland circulation is river- or...
| Main Authors: | , |
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| Format: | Article |
| Language: | en_US |
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American Geophysical Union
2012
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| Online Access: | http://hdl.handle.net/1721.1/68640 |
| _version_ | 1826188794724876288 |
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| author | Nepf, Heidi Andradottir, Hrund O. |
| author2 | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Nepf, Heidi Andradottir, Hrund O. |
| author_sort | Nepf, Heidi |
| collection | MIT |
| description | The flushing of littoral regions is governed by barotropic river flows, QR, and baroclinic exchange flows, ΔQ. This note presents field observations of two different flushing regimes in a shallow wetland that borders a lake. In spring, when river flows are high, the wetland circulation is river- or jet-dominated, ΔQ/QR < 1, and the river short- circuits through the wetland in a much shorter time than the nominal residence time. During summer low flows, however, the wetland circulation is dominated by exchange flows, ΔQ/QR > 1, that vary both on diurnal and synoptic (10–20 days) timescales in response to differential heating and cooling between the wetland and lake and to wind. These exchange flows can enhance wetland flushing by a factor of 10 relative to river flushing. A one-dimensional decoupled heat and flow model represents diurnal exchange flows in this system well and may be used to assess the importance of exchange flows in other systems. |
| first_indexed | 2024-09-23T08:04:48Z |
| format | Article |
| id | mit-1721.1/68640 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:04:48Z |
| publishDate | 2012 |
| publisher | American Geophysical Union |
| record_format | dspace |
| spelling | mit-1721.1/686402022-09-23T10:45:38Z Impact of exchange flows on wetland flushing Nepf, Heidi Andradottir, Hrund O. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Nepf, Heidi Nepf, Heidi Andradottir, Hrund O. The flushing of littoral regions is governed by barotropic river flows, QR, and baroclinic exchange flows, ΔQ. This note presents field observations of two different flushing regimes in a shallow wetland that borders a lake. In spring, when river flows are high, the wetland circulation is river- or jet-dominated, ΔQ/QR < 1, and the river short- circuits through the wetland in a much shorter time than the nominal residence time. During summer low flows, however, the wetland circulation is dominated by exchange flows, ΔQ/QR > 1, that vary both on diurnal and synoptic (10–20 days) timescales in response to differential heating and cooling between the wetland and lake and to wind. These exchange flows can enhance wetland flushing by a factor of 10 relative to river flushing. A one-dimensional decoupled heat and flow model represents diurnal exchange flows in this system well and may be used to assess the importance of exchange flows in other systems. National Institute of Environmental Health Sciences. Superfund Basic Research Program (grant P42-ES04675) 2012-01-23T20:17:10Z 2012-01-23T20:17:10Z 2001-12 2001-01 Article http://purl.org/eprint/type/JournalArticle 0043-1397 http://hdl.handle.net/1721.1/68640 Andradottir, Hrund O., and Heidi M. Nepf. “Impact of exchange flows on wetland flushing.” Water Resources Research 37.12 (2001) ©2001 American Geophysical Union en_US http://dx.doi.org/10.1029/2001WR000257 Water Resources Research Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union Prof. Nepf |
| spellingShingle | Nepf, Heidi Andradottir, Hrund O. Impact of exchange flows on wetland flushing |
| title | Impact of exchange flows on wetland flushing |
| title_full | Impact of exchange flows on wetland flushing |
| title_fullStr | Impact of exchange flows on wetland flushing |
| title_full_unstemmed | Impact of exchange flows on wetland flushing |
| title_short | Impact of exchange flows on wetland flushing |
| title_sort | impact of exchange flows on wetland flushing |
| url | http://hdl.handle.net/1721.1/68640 |
| work_keys_str_mv | AT nepfheidi impactofexchangeflowsonwetlandflushing AT andradottirhrundo impactofexchangeflowsonwetlandflushing |