A study on the effects of soil moisture, air humidity, and air temperature on wind speed threshold for dust emissions in the Taklimakan Desert

摘要

Soil and the atmospheric conditions are important factors that affect wind speed threshold of surface dust emissions. Based on the observed data of surface dust emissions in the Taklimakan Desert collected from March 2008 to February 2018, the effects of soil moisture, air humidity (vapor pressure), and air temperature on wind speed threshold were analyzed in this study. The results showed that the accumulated time of dust emissions over the decade was 3609.8 h, thereby accounting for 4.1% of the total observation time. In addition, the duration of dust emission in the four seasons were consistent with the pattern of summer > spring > autumn > winter. When the soil moisture is above 3.0-4.0%, the wind speed threshold for dust emission increases with increasing soil moisture. When the vapor pressure is above 10-15 kPa, the wind speed threshold for dust emission increases with increasing vapor pressure. There was a negative correlation between air temperature and the wind speed threshold for dust emission. When the air temperature was higher than 0.0 degrees C, the soil moisture decreased with increasing air temperature, and the wind speed threshold for dust emission was lower.