Abstract:

Based on the observation data from wind masts in Hangu and Dagang at the eastern coastal area of Tianjin from 2017 to 2019, the temporal variation characteristics of wind speed at different heights of wind masts were analyzed statistically, and the relationship between wind speed at 30~100 m and 10 m as well as the variation of wind shear index, were discussed.The results showed that the wind speed at each height had obvious seasonal variation characteristics.In spring, the wind speed was the highest, and the most prone to gales.The average wind speed, the number of gales days, and the intensity of gales were the highest.The wind speed was minimum during the transition period of summer and autumn.In addition, the wind speed had obvious diurnal variation characteristics, and the wind speed at each height reached the maximum in the afternoon.Correlation analysis showed that the wind speed at 30~100 m was positively correlated with that at 10 m.The difference in wind speed and wind shear index at each height and 10 m height showed similar diurnal variation characteristics, that is, they were both minima in the afternoon when sea breeze prevail.Comparing the characteristics of two wind masts, it was found that the mean wind speed in Hangu was larger, the frequency of gale weather was more frequent, the intensity of gale was more, and the diurnal variation of wind speed and sea and land wind was more obvious.

Key words: Gale, Coastal wind masts, Wind shear index