策勒绿洲-荒漠过渡带风沙前沿近地表沙尘水平通量观测

沙漠地区近地表水平输送的沙尘物质通量及其随高度的变化是沙尘输送过程的重要表现特征。在塔克拉玛干沙漠南缘策勒绿洲-荒漠过渡带风沙前沿平坦沙地的风沙观测场，利用BSNE集沙仪对近地表（2 m）不同高度沙尘物质的水平输送进行了观测，对其随高度变化特征进行了分析，并对近地表水平运动的沙尘通量进行了计算。结果表明：观测点沙尘物质的水平通量随高度的增加而减小，与高度的关系可用幂函数和指数函数表示；55%～58%的沙尘量在地表0.5 m高度以内传输；73%～75%在地表1 m高度以内传输；87%～89%在地表1.5 m高度以内传输；2010年5月25日至2011年5月24日，通过0～2 m高度的单宽总输沙量为1 846.7 kg•m^-1；其中PM80、PM50的输送量分别为1 192.0 kg•m^-1、387.9 kg•m^-1。

Near-surface Horizontal Aeolian Sand-dust Flux over an Oasis-desert Ecotone in Qira County,Xinjiang

Aeolian sand dust transport is a serious problem in many arid regions in the world, and it is considered to be as a significant part of global biogeochemical cycle. Deserts are the main sources of near surface aeolian sand dust transport, and aeolian sand dust transport process is closely related to the variation of near surface horizontal aeolian sand dust flux with height. In this paper, the variation of horizontal aeolian sand dust flux within height 2 m above the ground surface was discussed based on the one year observation on a level sand land in the south Taklimakan Desert by BSNE samplers. It was revealed that the horizontal aeolian sand dust flux was decreased with the increase of height, which could be described with the distribution of power function and exponential function. A 55%-58% amount of horizontal aeolian sand dust was transported within an air layer 0.5 m above the ground surface, a 73%-75% amount of that was transported within an air layer 1 m above the ground surface, and a 87%-89% amount of that was transported within 1.5 m above the ground surface. In the study area, the amount of horizontal aeolian sand dust load in a height range from 0 to 2 m was 1 846.7 kg•m^-1, in which the amounts of PM80 and PM50 were 1 192.0 kg•m^-1 and 387.9 kg•m^-1 respectively.