抄録
The objective of this paper is to investigate the statistical properties of the extreme value distribution of the annual maximum wind speed obtained by a probabilistic model. The probabilistic model modified from the previous one by considering a gaussian distribution of translating speed of typhoons and a gradient wind field yields the extreme value distribution of the annual maximum wind speed very well. The analysis based on this model leads to the following; (1) For the distribution of extreme winds caused by tropical cyclones such as typhoons, the Type III extreme value distribution with three parameters is preferable to the other Types. (2) The upper limit ω and the scale parameter k in the Type III distribution may be fixed as a constant in and near the Japanese Islands (ω=90m/s, k=6). (3) The location parameter u in the Type III distribution may be approximately obtained in eq. (14) as a function of the mean occurrence rate, λ, of typhoons. (4) Resulting that the Type III distribution is the most suitable for the estimation of wind speeds in typhoonprone regions, the control band based on the distribution involved almost all observed distributions acceptably at 8 sites for the period of 30 years.
