Abstract: Caragana microphylla Nabkhas is the main aeolian deposit in the agro-pastoral transitional zones in southeast Inner Mongolia Plateau. Field investigations on the airflow structure and wind-sand flow of some typical nebkhas showed that the direction and intensity of the airflow and the sediment transport rate varied with the different positions of the nebkhas. The airflow around the nebkhas and over the top of the nebkhas merged together at leeward and turbulences were developed thereafter with a vertical range of the height of the nebkhas and a horizontal range of 1.5 times of the height of the nebkhas. The wind velocity increased at windward and kept increase at the north and the south sides of the nebkhas, then reached the lowest velocity at leeward and then gradually increased back to the wildness wind speed. The main wind direction affected the airflow at leeward. Under the different wind directions, the wind velocity profile around the nebkhas showed non-logarithmic regularity. The wind velocity at the height of 0.3-0.6 m changed under different wind directions at the south side of nebkhas. In addition, sediment transport rates at the windward, the north and south the sides of the nebkhas were consistent with the change of the velocity. However, sediment transport rate at leeward changed because of the turbulence. Sediment transport rate decreased with the increase of the height at windward and at the both sides of the nebkhas, but showed no regularity at leeward.

Key words: Caragana microphylla, nebkhas, airflow structure, sediment transport rate, Inner Mongolia Plateau