Wind sand flow structure and its variation under different surface conditions in the Korqin sandy land were investigated
by measuring windblown sand fluxes with sand samplers during two wind storms. The results showed the following findings: (1) There was a considerable difference in the intensity of wind erosion among the four sandy lands. In the May 15 measurement, mean total windblown sand flux at 20 cm above the surface was 83.1 g/cm 2·h in the mobile sandy land, being 2.1 fold, 9.2 fold and 33.9 fold higher than the semi mobile, semi fixed and fixed sandy lands, whereas in the May 17 measurement, mean total windblown sand flux at 20 cm above the surface was 105.7 g/cm 2·h in the mobile sandy land, being 5.6 fold, 14.1 fold and 75.6 fold higher than the semi mobile, semi fixed and fixed sandy lands. (2) Over 60% of the total sediment near the 20cm surface was distributed within the height 0~10 cm and the total sediment decreased with increased height by a negative exponential function. (3) The particle size distribution analysis of the windblown sediment collected from individual layers showed that the proportions of coarse particles (diameter 1.0~0.5mm), fine particles (diameter 0.1~0.05mm) and silt and clay particles (diameter<0.05 mm) were very low, while medium sand particles (diameter 0.25~0.1mm) accounted for a considerable higher proportion (73%~91%) within any surface type, suggesting that the motion of sand particles near the surface is dominated by saltational fashion. The proportion of sand particles in diameter 0.5~0.25mm tended to decrease and that of silt and clay particles tended to increase with increase of height. (4) Both the total windblown sediment over the 20cm surface and windblown sediments at individual layers were negatively related to vegetation cover, but no statistically significant negative correlations were found between windblown sand mass and canopy height, soil hardness and surface roughness length.