Return to search

Seasonal variation of wind gustiness in a portion of the Columbia Gorge

The seasonal variation of wind speed fluctuations is studied at
four locations in The Dalles area of the Columbia River Gorge.
Three of the sites are located in or near the valley floor while the
fourth site is on top of a 900 m (3000 ft) ridge just north of The Dalles.
The speed fluctuations or gustiness at these sites varies with terrain
roughness, wind speed, and atmospheric stability.
Due to the channelling effects of the Gorge, wind flow in The
Dalles area is predominantly upriver or downriver. Strongest winds
occur from the west at all four of the sites that were analyzed.
Highest gustiness values occurred at the Martin Marietta site
located near the rugged foothills of the eastern slopes of the Cascade
Mountain Range. Moderate gustiness values were common at KCIV
located on the top of the ridge north of The Dalles and at the D.C.
Test Site surrounded by rolling hills. Smoothest flow was found along
the relatively level valley floor at The Dalles Dam.
Gustiness in relation to wind speed varied at all four sites.
Gustiness values increased with speed through the moderate speed
range at KCIV while gustiness decreased with speed at The Dalles
Dam and the Martin Marietta site. No distinct relationship was found
at the D.C. Test Site.
At KCIV changes in gustiness are directly related to the amount
of solar insolation and hence the atmospheric stability. Gustiness
values were highest during the summer and daytime values were
greater than those at night during both winter and summer. In contrast,
at the other three sites near or on the valley floor no distinct
relationship between the stability variations and the changes in gustiness
could be found. Results indicated that the gustiness values
during the winter at these three locations exceeded those during the
summer. It appears that the unstable nature of the post frontal
wintertime air mass is responsible for the strong and turbulent
northwest flow.
Although moderate speed fluctuations were common at KCIV,
this site is the most appealing of the four locations for wind power
generation due to the persistency of moderately strong winds during
both summer and winter. Least attractive of the four sites is Martin
Marietta where high gustiness values along with weak winter winds
provide little usable wind energy. / Graduation date: 1977

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28909
Date16 June 1976
CreatorsBaker, Robert W.
ContributorsHewson, E. Wendell
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

Page generated in 0.0023 seconds