塔克拉玛干沙漠北缘荒漠过渡带风沙流结构特征分析

利用多种集沙仪，通过野外实时输沙观测，对塔克拉玛干沙漠北缘荒漠过渡带的地表风沙流特征进行了分析，结果表明：① 100 cm高度范围内，总输沙量的47.3%分布在30 cm高度内，这一比例小于前人的研究结果；输沙量随高度的变化比较符合幂函数分布。② 风沙流输沙的粒径以细砂、极细砂与粉砂为主，各高度层所占比例均达99%以上；风沙流输沙平均粒径随高度增加而减小，沙尘的含量随高度增加呈现“象鼻”状分布。③ 风沙流中贴地层风速廓线受风沙相互作用的影响，不再符合对数分布，更加符合幂函数u=az^b分布。

Study on Structure of Wind-blown Sand Flow over the Desert Ecotone in the Northern Marginal Zone of the Taklimakan Desert

The damage of wind-blown sand flow is multiaspect,not only its destruction to soil surface texture and reduction of soil anti-erodibility,but also the affection on air quality and human activities.The Taklimakan Desert is the largest,warmest and driest desert in China,and it is also known as one of the largest mobile deserts in the world and one of the main source fields of sandstorm in China.So it is of signality to study the structure of wind-blown sand flow.In this paper,the structure of wind-blown sand flow over the Xiaotang area in a desert ecotone in the Taklimakan Desert was studied.The results showed that the proportion of transported sand quantity within a 30-cm height was higher than 47.3% of the total transported sand quantity near ground surface,and this result was different from that in previous studies.The transported sand quantity with height above ground surface changed in a power function way.The particle size distribution analysis of wind-blown sand sediment collected from different soil layers showed that the proportion of fine sand,very fine sand and silt was dominant(>99%).The average particle size was decreased with the increase of height.In wind-blown sand flow,wind profile near ground surface was not in a logarithmic distribution but in a power function distribution(u=azb).