Abstract: It is of great significance to study the characteristics of sand-dust varied with height for revealing the distribution traits of sand-dust in the surface layer. This paper collected data of horizontal sand-dust fulx and dust fall amount from the dust observation tower within the height of 50 m, located in the northeast of Ulan Buh Desert; and studied the effect of regional protection forest on change features of sand-dust horizontal and vertical flux. The results indicated that: ① Both horizontal sand-dust flux and dust fall amount decreased along with the height increasing. The distribution characteristics of horizontal dust flux and dust fall amount with height accorded with power function inside of the shelterbelt, and the distribution characteristics of them accorded with exponential function outside of the shelterbelt. ② The horizontal dust flux and dust fall amount were positively correlated. They could be presented by linear functions. ③ Both horizontal dust flux and dust fall amount with wind speed presented a linear relationship.

Key words: surface layer, horizontal sand-dust flux, dust fall amount, Ulan Buh desert ecosystem

摘要： 研究沙尘随高度的变化特征对揭示沙尘物质在近地层分布特征具有重要意义。通过收集乌兰布和沙漠东北部近地层50 m沙尘水平通量和降尘量数据，研究了该区域防护林对沙尘水平和垂直通量变化特征的影响。结果表明：①沙尘水平通量及降尘量均随高度的增加而减小，防护林内二者与高度的关系符合幂函数，防护林外二者与高度的关系符合指数函数；②沙尘水平通量与降尘量之间为正相关关系，二者可用线性函数表示；③沙尘水平通量和降尘量均与风速呈现线性关系。

关键词: 地表, 沙尘水平通量, 降尘量, 乌兰布和荒漠生态系统