关键词: 风蚀起沙, 临界摩擦速度, 起沙风速, 沙尘通量, 塔克拉玛干沙漠

Abstract: Based on the field observation and meteorological data at Tazhong of Taklimakan Desert, the critical friction velocity of dust emission by wind erosion and the threshold sand-moving wind velocity in Spring and Summer are analyzed in the paper. The dust emissions by wind erosion at Tazhong during the two sandstorm events on April 19 and July 19, 2008 are calculated. The results indicate that the critical friction velocity is about 0.26 m·s-1 and the near-surface threshold sand-moving wind velocity is about 4.1 m·s-1. The average values of down-wind sand flux during the two sandstorm events on April 19 and July 19, 2008 are 17.44×10-4 kg·m-1·s-1, 13.8×10-8 kg·m-2·s-1 respectively, and the vertical dust flux during these two sandstorm events are 164.69×10-4 kg·m-1·s-1 and 799.77×10-8 kg·m-2·s-1 respectively. The variation of dust flux is consistent with the variations of the wind velocity and the friction velocity.

Key words: dust emission by wind erosion, critical friction velocity, threshold sand-moving wind velocity, dust flux, Taklimakan Desert