Although flow deflectors are routinely placed in streams to create fish pool habitat, there is dissent in the literature as to what constitutes for them an appropriate design height to ensure their success. Our objectives were to (1) examine the temporal evolution of bed topography around submerged deflectors in a laboratory flume, for different deflector heights and discharge; and (2) quantify the flow dynamics in their vicinity. Results indicate that, all else being equal, higher deflectors (characterized by less overtopping) produce a greater volume of fish pools. In contrast, over a fixed deflector design, a higher discharge (synonymous with greater overtopping) results in larger pools, because flow velocities are then faster. We also observed differences in the temporal behaviour of scour: that next to high and medium height deflectors is self-similar, but not that for the shorter model. Our results challenge the notion that low deflectors are ineffective, provide information on the development of scour next to submerged structures, and reveal key differences between the geometry of the scour holes engendered by the different deflector height models.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.116074 |
| Date | January 2008 |
| Creators | Rodrigue-Gervais, Karen, 1981- |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Geography.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002842195, proquestno: AAIMR67013, Theses scanned by UMI/ProQuest. |
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