塔克拉玛干沙漠东南缘沙尘暴过程中近地表沙尘水平通量观测研究

沙漠是重要的沙尘源区,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特征。在塔克拉玛干沙漠东南缘若羌平坦沙地的风沙观测场,利用BSNE集沙仪对沙尘暴天气过程中近地表2 m内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表示;约66%的沙尘在地表50 cm高度以内传输;80%的沙尘在地表100 cm高度以内传输;观测点2009—2010年12次沙尘暴天气过程,通过0～2 m高度的单宽总输沙量为3 627.9 kg·m-1,PM80、PM50的输送量分别为1 430.4 kg·m-1、216.2 kg·m-1。

Observational Study on Near-surface Horizontal Sand-dust Flux of Sandstorms in the Southeastern Fringe of the Taklimakan Desert

Aeolian sand-dust transport is a serious problem in many arid regions in the world, and it is considered to be the significant part of global biogeochemical cycles. While deserts are the main source of aeolian sand-dust transport in the near-surface layer, and aeolian sand-dust transport processes are closely related to the variation of near-surface horizontal sand-dust flux with height. This paper discusses the variation of horizontal sand-dust flux within 0-2 m with height over the ground surface based on one-year observation on sandy land in the southeastern Taklimakan Desert by BSNE samplers. It is revealed that horizontal sand-dust flux amount decays with height, which can be described by power function. There is about 66% of the horizontal sand-dust flux transported within 0-50 cm over the ground surface, and 80% is transported within 0-100 cm over the ground surface. In the studied area, the horizontal sand-dust flux passing height from 0 to 200 cm is 3 627.9 kg·m-1, among them, the amounts of PM80 and PM50 are 1 430.4 kg·m-1 and 216.2 kg·m-1, respectively.