HR: 0830h
AN: OS41A-02    [Abstracts]
TI: Measurement of Longshore Sediment Transport on Galveston Island Texas
AU: * Ravens, T M
EM: RavensT@tamug.edu
AF: Texas A&M University, 5007 Avenue U, Galveston, TX 77551 United States
AU: Rogers, A
EM: RogersA@tamug.edu
AF: Texas A&M University, 5007 Avenue U, Galveston, TX 77551 United States
AB: Longshore sediment transport in the surf zone on Galveston Island, Texas, was studied using a instrumented sled that was pulled across the surf zone. Determination of the sand transport rate was challenging due to presence of fines. The instrument sled contained a LISST 100 for particle size distribution determination, four OBS sensors, and three velocity sensors. The sled occupied 10 to 15 stations, spaced about 10 m apart, and collected data for about 3 minutes at each station. Data from the LISST-100 and from the 4 OBS's was analyzed to determine the average vertical distribution of sand concentration, assuming that fines were vertically well mixed at each station. A logarithmic profile of average longshore current was calculated based on the velocity data. The longshore sediment transport was calculated as the spatial integral of the product of the sand concentration and velocity, and was related to the wave conditions at the point of breaking. The results indicated that the popular CERC formula, with K = 0.7, did a reasonable job of calculating sediment transport. Longshore sediment transport was greatest in the vicinity of the sand bars.
DE: 4512 Currents
DE: 4546 Nearshore processes
DE: 4552 Ocean optics
DE: 4558 Sediment transport
DE: 4594 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly