Through field investigation on wind speed

aerodynamic roughness

rate of sand transportation

and structure of wind-sand flow on different underlying surfaces

we found that vegetation cover can effectively prevent soil erosion by wind.In comparison of the fixed sandy land of 40% vegetation coverage with the drifting sand dune without coverage

the average wind speed at the height of 0.2 m was reduced by 43%

the successive time of threshold wind velocity for soil erosion was reduced by 85%

the threshold wind velocity for soil erosion was increased by 70%

and aerodynamic roughness was increased as much as 180 times.Compared with the drifting sand dune

when the speed of wind-sand flow is similar

the rate of sand transportation on the semi-fixed sandy land was reduced by 62.33%

while fixed sandy land

by 93.07%.The results indicate that a single plant can also reduce wind speed.Two single Artemisia ordosica can reduce wind speed at the height of 0.5 m by 59.4% and 19.8%

respectively.