해운대 해수욕장의 모래이동 한계수심 산정결과 비교 및 고찰

Abstract

The proper evaluation of sediment movement depth according to the incident waves are very important in the studies of beach processes that is related to the arrangement of coastal structure for beach protection. In this study, we estimated the representative wave from the wave observation data during Mar. 2012 to Feb. 2016 in Haeundae Beach by KHOA, then calculated the critical sediment movement depth and the appearance frequency of representative wave applied to the previous beach process studies. In Haeundae Beach sand erosions and depositions are occurs in active within 10m of depth then a little sand movement still occurs in 20m depth. According to the survey data, the distinct beach profile changes occurs within the DL –6.0m depth. In comparison with the critical sediment movement depth calculated by Hallermeier, Birkemeier, Sato-Tanaka and van Rijn's formula the critical movement depth become shallow in order of initial movement, general movement, surface layer movement, complete movement and closure depths. The van-Rijn’s initial movement depth is the most deep compared with the initial movement depth of Sato-Tanaka. On the other hand the Hallermeier’s closure depth and Sato-Tanaka’s complete movement depth is similar as the most shallow depth. A previous beach process studies in Haeundae Beach shows that the definition of storm wave or normal wave conditions is not clear. Therefore it is needed to determine the representative wave from the annual wave frequency distribution curve at the beach.