Document Type

Poster

Location

Ellensburg

Event Website

http://digitalcommons.cwu.edu/source/

Start Date

19-5-2016

Keywords

Driftwood, Elger Bay, Camano Island

Abstract

Previous studies on Elger Bay, Camano Island, WA hypothesized that the bay has been emptying of stored driftwood since the 1970's. To test this hypothesis, we conducted a research project using a combination of field data and historical imagery analysis with Google Earth and ArcGIS to mathematically compare the density of driftwood. Changes in driftwood area may indicate changes in sea level rise, bay subsidence, and/or anthropogenic activity. We found that the maximum driftwood extent was actually closer to the 1950's than the 1970's. In addition to overall extent we investigated the overall channel flow along Elger Bay by analyzing driftwood movement over time. Using data from different months and years, we were able to compare development of driftwood to analyze the channel flow. Our results indicate that the driftwood is mobile both in the front and back of the bay with annual changes in driftwood area and extent. There is also continuous movement of driftwood along major channels, resulting in changes in the geometry of the driftwood field. We expected to see movement along major channels and in the front of the bay; and driftwood in the back to be stationary. The numerical data disproved the hypothesis that the driftwood area reached a maximum in the 1970s and has been emptying since. Our other observations were consistent with our hypotheses, except for the mobility of driftwood in the back of the bay.

Poster Number

8

Faculty Mentor(s)

Breanyn MacInnes

Department/Program

Geological Sciences

Included in

Geology Commons

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May 19th, 12:00 AM

Channel Flow Studies Using Driftwood Density Analysis in Elger Bay, Camano Island, WA

Ellensburg

Previous studies on Elger Bay, Camano Island, WA hypothesized that the bay has been emptying of stored driftwood since the 1970's. To test this hypothesis, we conducted a research project using a combination of field data and historical imagery analysis with Google Earth and ArcGIS to mathematically compare the density of driftwood. Changes in driftwood area may indicate changes in sea level rise, bay subsidence, and/or anthropogenic activity. We found that the maximum driftwood extent was actually closer to the 1950's than the 1970's. In addition to overall extent we investigated the overall channel flow along Elger Bay by analyzing driftwood movement over time. Using data from different months and years, we were able to compare development of driftwood to analyze the channel flow. Our results indicate that the driftwood is mobile both in the front and back of the bay with annual changes in driftwood area and extent. There is also continuous movement of driftwood along major channels, resulting in changes in the geometry of the driftwood field. We expected to see movement along major channels and in the front of the bay; and driftwood in the back to be stationary. The numerical data disproved the hypothesis that the driftwood area reached a maximum in the 1970s and has been emptying since. Our other observations were consistent with our hypotheses, except for the mobility of driftwood in the back of the bay.

http://digitalcommons.cwu.edu/source/2016/cos/4