Field measurement study of wind characteristics at different measuring positions in a mountainous valley

The characteristics of wind in mountain valleys are complex; in this paper, we present a comprehensive analysis of these characteristics using data obtained from two wind masts located at hillside and at the bottom of a canyon. In view of the limited literature focusing on the effect of the location of measurement on the characteristics of wind in mountain valleys, we present a comparison of these characteristics in this paper. The wind characteristics investigated in this study include the mean wind speed, mean wind direction, turbulence intensity, gust factor, wind power spectra, and vertical coherence. The results indicate that the mean wind speed, turbulence intensity, and wind power spectra cannot be predicted accurately using specifications or standards. The mean wind direction at a high wind speed is always along the canyon. A modified exponential coherence model can depict the vertical coherence effectively. Furthermore, wind characteristics are to some extent affected by the variations in height and locations of measurement, but still valuable for engineering practice, and a 30-m wind mast can meet the needs instead of a 50-m one.