Characteristics of intense winds with significant variability in a mountainous valley of the Tibetan Plateau based on field measurement

Abstract

Due to the influence of local complex topography and local severe convective weather system, wind events measured in mountainous valleys exhibit significant variability, that is, wind speed and wind direction often change rapidly in a short duration, which can pose a serious risk to the safety of many wind-sensitive infrastructures. However, the characteristics of steady winds in the atmospheric boundary layer have attracted extensive attention, but research on wind events with significant variability in mountainous valleys is still very insufficient. Therefore, based on the long-term wind field data collected by ultrasonic anemometer in a typical mountain valley of the Tibetan Plateau, the wind characteristics of these special wind events are comprehensively investigated. First of all, an effective quantifying approach is established to evaluate the variability levels based on the proposed spread metrics in statistics, which enables the identification of wind events with significant variability from the measured datasets. Furthermore, with the aim of obtaining turbulence components in three directions, and time-varying means to describe the trends of wind speed, wind direction, and angle of attack, an analysis strategy based on the moving average is presented. Finally, the mean characteristics and turbulence characteristics are investigated and compared with the steady wind events. The outcome of this study is expected to enhance the understanding of these special wind events and provide valuable reference for wind–structure interaction analysis in mountainous valleys.