油蒿是中国沙区分布较为广泛的沙生半灌木植物，也是库布齐沙漠南缘的主要植被类型。油蒿灌丛与风沙相互作用形成灌丛沙堆和抛物线形沙丘。本文根据野外植被调查、风沙观测、沉积物采样分析结果，探讨了油蒿灌丛及灌丛沙堆与风沙输移之间的关系。主要结论如下：在干河床下风侧的平坦地表，顺风向植被盖度呈先增大后减小的趋势，与覆沙厚度一致。风速在植被平均高度范围内，随植被盖度增大而减小，超过植被高度后，风速随盖度变化不明显。输沙率变化为先减小后增大，与植被盖度变化相反；顺风向平均粒径呈先减小后增大的趋势，且灌丛沙堆积沙体表层沉积物平均粒径均小于对应丛间地。单一油蒿灌丛沙堆气流观测结果表明，绕过灌丛沙堆两侧的气流和越过沙堆上部的气流在背风侧汇集，并在两倍沙堆高度范围内出现垂直轴的涡流。在距地面0.3m高度上，气流在迎风坡坡脚受灌丛阻挡而风速减小，绕过沙堆两侧的气流因流线压缩而风速增加，至背风坡坡脚因气流分离而风速剧降，之后在背风侧顺风向逐渐增大并恢复到旷野风向风速。在距地面4m高度范围内，除迎风坡坡脚以外，其它各测点风速随高度均不遵循对数规律。在灌丛沙堆背风侧2~5倍沙堆高度（2H ~5H）范围内，风速廓线受灌丛沙堆的影响较为显著。单一灌丛沙堆背风侧风速大小受其形态、来风方向及强度的显著影响。灌丛沙堆背风侧气流恢复区的长度约为4H ~6H，并随灌丛疏透度的增大而增加。沙堆背风坡坡脚的相对风速随灌丛沙堆垂直于风向的宽度和沙堆高度增大而减小，与沙堆顺风向长度以及灌丛植株高度无明显关系。同时，背风坡坡脚风速与来风强度及风入射角大小成正比。灌丛沙堆周围输沙率在迎风侧和两侧与风速变化一致，呈先增大后减小的趋势。各部位的输沙率随高度均呈指数函数递减。灌丛沙堆表层5cm沉积物以细砂，极细砂为主，由迎风坡坡脚经沙堆顶部到背风坡坡脚，平均粒径值逐渐变细，最细粒径值出现在背风坡坡脚处，后由此处顺风向逐步增大，与风速变化趋势相一致。

Artermisia ordosica is the psammophytic half-shrub and widely distributed in desert, China.At the same time, it is the main vegetation type in the southern Kubqi desert. According to field investigations on vegetation,wind-sand flow and analyze the grain size. We discussed Artermisia ordosica Nebkha’s distribution and its effects on sand transport and deposition. Simultaneously we explored the relationship among Nebkhas shape, airflow structure and sediment transport rate. The main conclusions are as follows:The vegetation coverage increased at first and then decreased along wind, so did the sand thickness. Below the average heigh of Nebkhas, the correlation between wind velocity and vegetation coverage was negative, when heigh of Nebkhas was higher than the average, the law disappeared. The changes of sand transport and average grain size were opposite to the vegetation coverage along wind that decreased firstly and then increased. What’s more, the average grain size of intra-Nebkhas was smaller than that of inter-Nebkhas.The observation of single Nebkha showed that the airflow passing the Nebkhas merged together at leeward. Moreover, turbulence were seen at leeward, the range was about 2 times as long as the height of Nebkhas. Within 0.3m of the surface, the wind velocity showed the regulation of alternate of decrease-increase. Within 4m of the surface, except windward, the wind velocity profile showd non-logarithmic regularity. The effect of Nebkhas was most significant within distance of 2H~5H which was closely positive correlation with Nebkhas height. The wind velocity at leeward of Nebkhas was affected by its shape, the direction and intensity of wind significantly. The wind speed recovery was about 4~6H. Perpendicular to N-S, its changed with wind direction was also evident. At the same time, the recovery of wind at 0.3m at leeward was influenced by vegetation, the length of wind speed.Airflow of the leeward was affected by Nebkhas shape, wind velocity and wind direction significantly. There was a positive correlation between Nebkhas width and the wind velocity of the leeward. And there was no significant function between Nebkhas length along-wind with wind velocity of the leeward. Meanwhile the wind velocity of the leeward increased with the wind velocity and angle of incidence.The sediment transport rate at windward, both side of Nebkhas was consistent with the changing of the wind velocity. It increased firstly and then decreased. The flux profile at different positon of Nebkhas was following the positive exponential function. From the windward to the leeward, the mean grain size of 5cm surface sediment is turning smaller and reached the least at leeward and then gradually increased in along-wind direction.