Numerical Studies on Rip Current Control Using Scene-friendly Structures at Haeundae Beach, Korea

Abstract

The sporadically occurring rip currents put swimmers in risk during the season of every summer vacation. It is known that the rip current generation is affected by the characteristics of incident waves and bottom topography but the mechanism of the rip current occurrence is still not clear. In order to understand the mechanism of the rip current and to establish countermeasures, 3D numerical simulation was performed based on the realistic bathymetry of Haeundae Beach by using LES-WASS-3D. The numerical simulation results showed that the wave heights vary parallel to the shore line by inequality of bottom bathymetry (submerged shoal and rocks) and this wave height variation induces the water level difference. The model results also showed that the rip currents were generated through the region of relatively deep water and low water level that is caused by the water level difference. The present study suggested scene-friendly structures such as submerged breakwaters, drainage layers, and gabions as the countermeasures of rip current control. These structures successfully reduced rip current by controlling the energy unbalance in the region of rip current occurrence.