Wave-induced current simulated by wave-current coupled model in Haeundae

The wave-induced current in Haeundae, at the southeastern end of the Korean Peninsula, is one of the main causes of beach erosion. The Korean government recently initiated a beach restoration project for Haeundae beach to protect the famous beach against wave-induced currents generated by waves during summer and winter. To mitigate beach erosion, two submerged breakwaters and a sand nourishment program were initiated in 2013. With the support of the Korean government, we have also started an R&D project to develop coastal erosion control technology in order to understand the processes of beach erosion by measuring sediment transport and hydrodynamics in Haeundae coastal waters, including the development of a numerical simulation method. The aim of this study is to understand the main processes of wave-induced currents that cause erosion at Haeundae beach by considering wave and tide interactions, using a wave current coupled model compared with long-term observed wave and current data. We found that the cross-shore current during summer is mainly caused by the eddies produced by wave-induced currents generated by strong high waves during a Typhoon approaching from the SSW and S directions. During other seasons, a longshore current is produced by swell waves coming from the E and ESE directions. In comparisons with the measured data, we also found that the wave-induced current is well simulated by a wave tide coupled model in Haeundae with a coastal environment of wave and tide interaction.