Uncertainty of Extreme Storm Surge Estimation by High Wind Sea Surface Drag Coefficient and Future Typhoon Change

Abstract

Japan has been constructing long coastal defense since the storm surge disaster with a loss of 5,000 lives by Typhoon Vera in 1959. The defense is designed for the storm water level including the storm surge of the standard typhoon based on Typhoon Vera. Stochastic typhoon model, simulating various typhoon track and intensity with Monte Carlo method, is one of useful tools to estimate the return period. According to recent research output the return period of the storm surge of the standard typhoon is near 100 years or more at three major bays in Japan. But there is uncer-tainty by some of parameters and models in the stochastic simulation. Sea surface drag coefficient under high wind speed and future change in typhoon intensity and track are critical to extreme values of the storm surges.

Trend Model of Sea Extremes

“…The statistical analysis for extreme values has become widely applied and demonstrated in many practical studies. Bernardara et al (2010), Burzel et al (2010), Dong and Ji (2010), Goda et al (2010), Jonkman et al 2010, Kawai et al (2010), Kortenhaus and Oumeraci (2010), Mendez et al (2010), Mendoza et al (2010), Mertens et al (2010), Mudersbach and Jansen (2010), Naulin et al (2010), Yasuda et al (2010), Wahl et al (2010) are found in this conference papers. Those studies discussed on regional analysis, multivariate extreme values model by copula, joint distribution of waves and surges, the resultant probability distributions by numerical simulation based on stochastic typhoon models, parameters estimation by L-moments method, flood risk analysis and non-stationary model with covariates and so on.…”