Basic Design Wind Speed Map for Typhoon Winds Based on an Active Period of Typhoons by a Probabilistic Procedure

Strong winds due to typhoons are dominant for building design in the Japanese Isles. Basic design wind speeds for typhoon winds are given as a map over the Japanese Isles in friction free gradient wind. The map is prepared by indirect probabilistic procedure based on statistical properties of typhoons which struck the Japanese Isles for 20 years from 1950. This period was the most active in recent years.Estimated wind speeds from observed annual maximum typhoon wind speeds at 10m above the ground are compared to those of this analysis at 140 weather stations for the same period. The conversion factors from the friction free winds to the surface ones are seemed to be natural than the factors depending on the surface roughness around the weather stations.