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采用风洞模拟手段对地处半湿润区的北京市农田土壤风蚀中的粉尘释放规律进行研究。结果表明,研究区农田粉尘释放强度随风速增大呈指数规律增大,粉尘在风蚀物的含量随风速增大呈指数规律降低。近地表粉尘质量流量随高度增加呈幂函数规律降低,在风蚀物中的含量随高度增加呈线性增大。粉尘粒径随风速增大而变粗,之后达到稳定状态。近地表粉尘粒度组成沿垂直方向的变化可以划分为两段,0～20 cm高度层的双峰态分布和20～60 cm高度层的三峰态分布。随着高度增加,释尘粒度组成变细。
Wind tunnel simulation was used to study the law of dust release in farmland soil wind erosion in Beijing sub-humid area. The results showed that the release intensity of farmland dust increased exponentially with the increase of wind speed, and the content of dust in the wind erosion material decreased exponentially with the increase of wind speed. The near-surface dust mass flow rate decreases with the increase of height as a function of power function, and the content in the eroded material increases linearly with height. Dust particle size increases with wind speed and thicker, and then reach a steady state. The variation of particle size distribution in near-surface dust in the vertical direction can be divided into two sections, the bimodal distribution at 0-20 cm altitude and the tri-state distribution at 20-60 cm altitude. As the height increases, the dust release particle size becomes thinner.