关键词: 风蚀, 观测试验, 风沙流, 临界摩擦速度, 塔克拉玛干沙漠

Abstract: Field observation experiments on dust emission by wind erosion were conducted in Taklimakan Desert. Some analyzing results are obtained. The underlying surface situation directly influences sand flow structure. The sand-transporting volume of sand flow in Tazhong, Xiaotang and Ruoqiang decreases gradually with height. The sand-transporting volume at the height of 0~100 cm in Tazhong and Ruoqiang meets the exponential function completely, but that in Xiaotang deviates from the exponential function partially. 72.4%, 47.3% and 62.6% of sand-transporting volume at 0~100 cm are distributed in 0~30 cm in Tazhong, Xiaotang and Ruoqiang, respectively. The particles in sand flow are mainly fine sand, very fine sand and silt, in which 43.8%~75.5% is very fine sand. Wind speed profiles of near-surface layer follow u=azb distribution, and all the fitting coefficients are larger than 0.93. The change trend of rebounding particles is identical with that of wind speed at height of 2 meters, and the threshold friction velocities in Tazhong, Xiaotang and Ruoqiang are 0.25 m·s-1, 0.27 m·s-1, 0.21 m·s-1, respectively.

Key words: wind erosion, observation experiment, sand flow, threshold friction velocity, Taklimakan Desert