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Quantifying the rapid evolution of a nourishment project with video imagery

Journal of Coastal Research

By:
, ,
DOI: 10.2112/04-0280.1

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Abstract

Spatially and temporally high-resolution video imagery was combined with traditional surveyed beach profiles to investigate the evolution of a rapidly eroding beach nourishment project. Upham Beach is a 0.6-km beach located downdrift of a structured inlet on the west coast of Florida. The beach was stabilized in seaward advanced position during the 1960s and has been nourished every 4-5 years since 1975. During the 1996 nourishment project, 193,000 m 3 of sediment advanced the shoreline as much as 175 m. Video images were collected concurrent with traditional surveys during the 1996 nourishment project to test video imaging as a nourishment monitoring technique. Video imagery illustrated morphologic changes that were unapparent in survey data. Increased storminess during the second (El Nin??o) winter after the 1996 project resulted in increased erosion rates of 0.4 m/d (135.0 m/y) as compared with 0.2 m/d (69.4 m/y) during the first winter. The measured half-life, the time at which 50% of the nourished material remains, of the nourishment project was 0.94 years. A simple analytical equation indicates reasonable agreement with the measured values, suggesting that project evolution follows a predictable pattern of exponential decay. Long-shore planform equilibration does not occur on Upham Beach, rather sediment diffuses downdrift until 100% of the nourished material erodes. The wide nourished beach erodes rapidly due to the lack of sediment bypassing from the north and the stabilized headland at Upham Beach that is exposed to wave energy.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Quantifying the rapid evolution of a nourishment project with video imagery
Series title:
Journal of Coastal Research
DOI:
10.2112/04-0280.1
Volume
21
Issue:
4
Year Published:
2005
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
633
Last page:
645
Number of Pages:
13