The Determination of Typhoon Design Wave By Synthetic Probibility Method

In summer and autumn, typhoons always take place in the northwest pacific. in the northern hemisphere, the typhoon is a large, anticlockwise, atmospheric eddy. Due to the strong wind speed, huge waves are generated within the typhoon area. Hence, the design waves for maritime structures are determined by typhoon waves. Bretschneider's hindcasting method for typhoon waves is the unique way to estimate typhoon waves by a single set of typhoon parameters. The parameters are the latitude and longitude of typhoon center, center atmospheric pressure, radius of typhoon wind field, moving speed and moving direction. If a location is specified, a wave height and period can be estimated. The typhoon parameters can be regarded as random variables. Some of the random variables can be regarded as being independent. Hence, the sample joint distribution of the typhoon parameters can be easily set up. Then a distribution of wave height is calculated. By introducing an average typhoon occurrence per year, the return period of a specified wave height is estimated.