조간대가 발달한 서해연안에서 흐름장 해석에 관한 연구

Abstract

A sediment transport is affected by waves, wave induced currents, tidal currents and wind induced currents in the littoral zone. This study is aimed to build a numerical tool of littoral currents by linear coupled method. The above method is applied to the Gusipo beach by using the field observation data on 16th August, 2011. In that time, the spring tide range was 6m, significant wave height below 0.5 m and dominant wave direction was SW, average wind speed was 3 m/s and dominant wind direction was S. Tidal current is calculated in real time. Wave induced current and Stokes drift is calculated every 1 hour by using the 3 hours interval of observed wave data. Then the particle tracking methods is used to calculate the littoral currents pattern. The computed numerical littoral current pattern is compared with the track of the GPS equipped drogue at the same time. The results shows the tidal current is dominant component of nearshore currents and the wave induced current is very week in the narrow surf zone. Also the Stokes drift shows a few cm/s according to the low waves. The observed current direction indicate a similar pattern with the result of the coupled numerical value. However observed average drift speed of drogue is faster than the calculated result about two times owing to the wind effects. The suggested real time comprehensive littoral current prediction model in this study will be useful on the study of littoral sediment transport precesses.