Estimation of Storm Surge Inundation and Hazard Mapping

Typhoon is the most serious natural disaster in Korean coastal area. Many peoples died by storm surge inundation every year. And typhoon caused a lot of damage to property. Climate changes due to global warming are producing a stronger natural disaster. Coastal zones have been damaged by typhoons and accompanying storm surge. Especially, the most serious loss of life and terrible propertydamage caused by typhoon Maemi in 2003. After then, there has been an increased interest in these coastal zone problems. If storm surges coincide with high tides, the loss of life and property damage due to high waters arc even worse. Therefore it is desirable to accurately forecast the amount water level increase. In this study, using a numerical model FVCOM(finite volume coastal circulation model, Chen et al., 2004), storm surge was simulated to examine its fluctuation characteristics for the coastal area behind Masan, Yeosu and Busan city in Korea. In the numerical model, a moving boundary condition(wet-dry treatment) was incorporated to explain wave inundation. Numerically predicted inundation regimes and depths were compared with measurements from a tidal gage each area. Comparisons of the numerical results and measured data shows a good correlation. The numerical model adopted in this study is expected to be a useful tool for analysis of storm surges, and for predicting inundation regimes due to coastal flooding. Many coastal cities including low-lying areas were flooded during strong typhoon. So it is necessary to consider detailed evacuation planning, including hazard map, preparation of evacuation site, and sustainable city planning against storm surge inundation problems. For this study, we used 201 typhoon passing through Korea during the past 55 years since 1950. Typhoon wind model was used to estimate wind forcing and air pressure data for each typhoon. We estimated the spatial statistical analysis for inundation level as each return period. And finally we suggest the example of coastal hazard map in the Korean coast(Masan, yeosu and Busan city)