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Date Permissions Signed

2-23-2018

Date of Award

Spring 1990

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Geology

First Advisor

Schwartz, Maurice L.

Second Advisor

Suczek, Christopher A., 1942-2014

Third Advisor

Terich, Thomas

Abstract

Tidal-flushing of the proposed Lummi Bay Marina was studied using a physical model. The model was distinct from those of other regional marinas in that it included a berm around the edges, depth contours,sloping walls, and simulated mixed-semidiurnal tides. Spectrophotometric measurements of absorbance of dye in water resulted in the calculation of exchange-coefficients and flushing efficiency. Exchange coefficients in the physical model increased with increasing tidal range, suggesting a tendency for decreased water quality during smaller tides. Exchange was best in spring-tide simulations, but water tended to stagnate during the smaller ebb and flood cycles in both spring and neap simulations.Water quality in the proposed Lummi Bay Marina will probably also vary with tidal range and may be vulnerable to depletion of dissolved oxygen and increased temperature during periods of smaller tidal exchange.

Circulation gyres forming in the model contained less-mixed water toward their centers than at their edges. The primary counterclockwise- gyre retained enough momentum to remain intact throughout a tidal cycle.Neap tides did not induce as strong a circulation of water as did spring tides. Secondary clockwise-gyres formed in the north and south corners of the model over the berm. Those gyres were destroyed each time the berm was exposed, causing short-term water-quality problems. In the event of construction of the marina, the problem of tidal-flushing should be studied using a field approach to verify the results of this study.

Type

Text

Keywords

Tidal-flushing, water-quality, Lummi Bay Marina

Publisher

Western Washington University

OCLC Number

1041856586

Digital Format

application/pdf

Geographic Coverage

Lummi Bay (Wash.)

Genre/Form

masters theses

Language

English

Rights

Copying of this thesis in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Included in

Geology Commons

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