An Observational and Numerical Study of Storm-Induced Morphologic Changes at Sanpo Beach, Korea

Abstract

This study was conducted to investigate morphological changes at Sanpo Beach due to the storm through field observation and numerical simulation. Sanpo Beach located on the southeast coast of Korea had been significantly affected by typhoon Goni while some changes in beach profile was expected due to the strong storm-induced currents. Series of field observations on the beach topography, bottom bathymetries, shorelines, sand samples, and incident waves were carried out in order to investigate the morphological changes at Sanpo Beach during the typhoon season. In particular, Real Time Kinematic-Global Positioning System (RTK-GPS) and single-beam echo-sounder were deployed to collect beach topography and bottom bathymetry data, respectively. Observational results represented spatial and temporal changes of shoreline and sand bars during a storm event. For more close look at the process of morphologic changes derived by the sediment transport mechanism, field-scale numerical simulations were performed in parallel using Xbeach. Xbeach is one of the widely-used, open-source models which calculate sediment transports and morphologic changes by hydrodynamic processes of short (and/or long) waves, wave-induced setup and unsteady currents. Bathymetric evolutions, as well as shoreline changes predicted by the numerical results, revealed good agreements with observational data.