A STUDY ON THE RATIO OF FRICTION-FREE WIND AND SURFACE WIND FOCUSING ON RECURRENCE WIND SPEED

Abstract

Typhoon simulation is one of the methods to obtain recurrence wind speed. The existing wind speed model used in the simulation requires roughness length for each wind direction. However, when the roughness length is estimated from the observed wind speed, there is a problem that the value differs depending on typhoons. In this research, we investigated the characteristics of the recurrence wind speed ratio (RWR) of Friction-Free Wind and the surface wind. And a model for estimating the recurrence wind speed was proposed. As a result, it was shown that RWR does not depend on the return period, and the proposed method can be applied at the point where observed values exist. In addition, it was shown that RWR is affected by height above the ground and terrain.