Influence of Wind-sand Flow on Soil Erosion

The damage of wind-sand flow is multiaspect, not only its destruction to soil surface texture and weakening to anti-erodibility of soil, but also affection on vegetable normal growth and mutilating to industrial and agricultural facilities. In this paper, influence of wind-sand flow on soil wind erosion was discussed using portable wind tunnel to simulate natural wind. The results indicated that critical threshold wind velocity of soil surface can be reduced when wind-sand flow appears, and this makes soil more easily to be eroded. The influence on wind erosion had different characteristics under variant wind velocity scope. Wind erosion rate increases slightly in a lower scope of wind speed, while a rapid increase presents in a higher period of wind speed which accompanies a contrast of more than 5 times compared with clean wind, when wind velocity exceeds 10m/s, wind erosion rate decreases dramatically. This phenomenon showed that more sand saltates at a higher height when it obtains more kinetic energy, which weakens the anti-erodibility of soil, although wind erosion rate is greater than that of it is under clean wind condition. Because of sandy mutual impacting and abrading, it attenuates the anti-erodibility of soil making ground surface to be eroded easily, so integrated ways should be take into account to control the source of wind-sand flow. This is the key to inhibit expand of desertification and to improve ecological environment.