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ABSTRACT Lee, J.; Kim, I., and Lee, J.L., 2018. Improving the performance of rip current forecasting index with a focused on Haeundae Beach, Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1556–1560. Coconut Creek (Florida), ISSN 0749-0208. Rip currents can potentially drag swimmers into deep water, beyond seaward sand bars, and hence pose great threat to beach visitors worldwide. The primary aim of this study was to develop a method for improving the performance of rip current forecasting indices to more effectively, demonstrate a rip current warning level. The previous rip current forecasting index was established with four predictive levels: notice, watch, warning, and danger. The new index is based on a numerical model, using wave and wind data as well as forecast information. Through this study, standardization of rip current occurrence levels has been achieved, by using CCTV images recorded during the summer of 2015. Better forecasting accuracy was obtained given the improvement in predicting the rip current index for Haeundae, and was established in association with the Korean Meteorological Administration. The usefulness of the rip current predictive index on Haeundae Beach was determined through a matrix correlation analysis between the observed and predicted rip current levels. In addition, the accuracy of the prediction results was calculated using the new rip current forecasting index during the summer of 2016. It is necessary to continue the development of predictive studies for risk mitigation in a variety of coastal environments. [ABSTRACT FROM AUTHOR]

Bae, J.S., Yoon, S.B., Choi, J., 2013. Boussinesq Modelling of a Rip Current at Haeundae Beach. The rip current occurring at Haeundae beach in Busan, South Korea was numerically investigated under directional random wave environment. The numerical simulations were performed using a fully nonlinear Boussinesq equation model, FUNWAVE which is capable of resolving phase interaction and simulating nearshore circulation since it includes the effect of wave-induced momentum flux and horizontal turbulent mixing. To examine the modelling, the rip current occurred on the 12th of June, 2011 at Haeundae beach was simulated by using observations. The results of numerical simulation showed the time-dependent evolution of the wave-induced nearshore circulation that was caused by transformation of random waves due to the unique topography of Haeundae beach. And, it was found that the rip current was well generated and developed through the region where relatively lower wave heights were caused by refraction and diffraction of waves due to the topographical characteristics (i.e., submerged shoal). In addition, we found that a narrow-banded spectral wave (i.e., a swell spectrum) close to a regular wave generates stronger rip current than a broad-banded spectral wave under an equivalent wave height and period condition. [ABSTRACT FROM AUTHOR]

Yoon, H.S., Kang, T.S., Nam, S.Y., Kim, J.T., and Park, J.H., 2007. Measuring coastline morphodynamics using video-based techniques at Haeundae Beach, South Korea. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1106 – 1111. Gold Coast, Australia, ISSN 0749.0208 In this study, video-based monitoring systems were installed at three locations on high-rise buildings in Haeundae, Busan, South Korea and beach image data were obtained from September, 2003 to December, 2005. Through quantitative analyses (statistical and time-series analyses) of the observed video image data, areal changes in Haeundae Beach and the shoreline were identified and summarised as follows. 1) Shoreline changes varied according to season and could be divided into four sections (east side section I: 250 m; II: 350 m; III: 300 m; west side section IV: 250 m). The biggest change in beach width occurred in section III; the change pattern at section IV differed from that at the other sections. The shoreline usually regressed (eroded) during the typhoon period (summer) but progressed (by sedimentation) during other seasons. 2) The overall change in beach width was correlated with the frequency of typhoons during the same period with abrupt beach erosion occurring between July and September, when typhoons struck. However, beach erosion and sedimentation at both ends of the beach during winter and summer were opposite of that at the centre of the beach. 3) During the video-monitoring period the maximum beach area was approximately 42,689 m2 and the minimum area was approximately 36,100 m2. The beach area was reduced due to typhoons and high waves by about 15.4%. 4) The beach area decreased by 6,400 m2 in summer during the typhoon period but rose by 5,300 m2 through winter resulting in an 82.8% recovery. As a result, the total beach area declined by approximately 17.2% during the observation period. [ABSTRACT FROM AUTHOR]