Efficient Real-time Erosion Early Warning System and Artificial Sand Dune Breaching on Haeundae Beach, Korea

Abstract

An attempt to simulate real-time erosion on Haeundae Beach, Korea, was suggested in a previous study. The present paper is a sequential study comparing coastal sediment spatiotemporal changes on sandy beaches for horizontal and selected transects over a 2-m threshold wave height set with reference to Typhoon Chaba of 2016. It was found that erosion persisted for more than 17 h during the overall typhoon passage. By coupling heterogeneous models created with Perl script, Advanced Circulation (ADCIRC) + Simulating Waves Nearshore (SWAN) + XBeach, it is possible to satisfactorily predict beach morphology changes 12 h before onslaught, with both qualitative and quantitative accuracy. Moreover, this proposed scheme can be effectively extended for operational purposes. In addition, a series of numerical simulations hindcasting the breaching and downfall of an artificial coastal dune were performed. An artificial sand dune constructed on Haeundae Beach in 2012 breached and collapsed due to storm contact. Here, simulation results indicate that the weak points of the sand dune responded differently to the storm. In addition, the collapsing procedure and magnitude changes occurred differently along the dune. Thus, it can be concluded that precise pre-design of artificial-sand dune location and size is very important, and must be performed for a target storm return period.