JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2017, Vol. 60 ›› Issue (01): 123-128.doi: 10.3969/j.issn.1000-2006.2017.01.019

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Characteristics of wind velocity fluctuation over Gobi underlying surface

SHANG Heying, YIN Zhongdong*, ZHANG Peng, LAN Ruijun   

  1. College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
  • Online:2017-02-18 Published:2017-02-18

Abstract: 【Objective】This study is to investigate the characteristics of wind velocity fluctuation in the wild area for the theoretical foundation of the research of wind erosion in turbulent flow.【Method】Most previous studies of wind-blown sand were conducted for the wind tunnel, and limited actual wind field data were available because it is difficult to be determined due to poor natural conditions in Gobi area. Therefore, in this study, the instantaneous wind velocities of different height were measured in Gobi surface of Carabeli project area, Xinjiang Uygur Autonomous Region in 2015. Depending on the data, we mainly analyzed the characteristics of wind velocity fluctuation of different heights(0-2 m)from several aspects, that were the wind velocity fluctuation, turbulence intensity, wind velocity fluctuation intensity, and the relationship between them and wind velocity using statistical methods. In addition, the optimal fitting equation was selected by the method of curve estimation in regression analysis.【Result】The variation of instantaneous wind velocity and wind velocity fluctuation of different heights is complex, and their change trends with time are almost similar. In the period of 0-50 min, the instantaneous wind velocity fiercely jumps at the altitude of 40 cm and it tends to be smaller. The amplitude of wind velocity fluctuation is very large, and its maximum value is close to 6 m/s. However, 90% of it is concentrated in the range of∣0-3∣m/s. The probability distribution of wind velocity fluctuation is Gauss distribution. There is a unitary linear relationship between fluctuation intensity and wind velocity. The stronger the wind velocity, the stronger the fluctuation intensity is obtained. The maximum value of wind velocity fluctuation intensity is 2.41 m/s. The turbulence intensity varies between 0.14 and 0.21, and its mean value is about 0.17. It belongs to the high turbulence intensity. No obvious relationship between the height and average wind velocity below 2 m is observed.【Conclusion】The wind velocity fluctuation is non-stationary. As the wind velocity and height increase, the wind velocity fluctuation tends to be stronger in Gobi. The wind velocity fluctuation cannot be ignored when the wind erosion is studied, especially in the windy weather.

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