Modelling of Storm-induced Seawater Flooding in the Suyeong River Area, South Korea: A Case Study due to the Storm Surge and Waves during Typhoon Sanba

Abstract

The Suyeong River Area (SRA), located in Busan, a major city on the southeastern coast of South Korea, is frequently damaged by storm-induced seawater flooding. One of the main reasons for seawater flooding is the propagation of storm surges and wind waves through the Suyeong River in the SRA. In this study, a series of prediction systems of storm tides, surges, waves and resultant seawater flooding for the SRA based on unstructured meshes with a high resolution of approximately 10 m covering the entire flood plain and a HPC-based parallel tide-surge-wave model were developed. Meteorological forcing variables such as wind and air pressure calculated by the parametric tropical cyclone model based on typhoon information were used in the storm-surge and wave models. The modeled meteorological data were in good agreement with observations of both the wind and air pressure. The simulated surge heights and wave properties showed good agreement with the observations as well. Waves reached the mid-stream area of the SRA, likely affecting the duration of seawater flooding. The prediction system in this study can reasonably simulate tide-surge-wave and resultant seawater flooding (coastal inundation) during extreme conditions, e.g., storms in the SRA of Busan, South Korea.