毛乌素沙地风沙流结构的研究

运用曲线拟合、拟合方程等方法,对毛乌素沙地南缘流动沙丘0～30cm垂直高度范围内的风沙流结构进行了分析研究。结果表明:在0～30cm高度,输沙率均与风速成正比,与高度成反比,幂函数拟合关系最佳。其中,各高度层输沙率随风速的变化分别呈幂函数或指数函数关系,同风速下输沙率随着高度的增加而减小,呈幂函数或指数函数关系;随着风速和气流中总输沙率的增加,0～30cm高度范围内的绝对输沙率增加,相对输沙率(%)的变化为下层趋于减少,中层略变,上层增加,风沙流结构的特征值λ增大;风沙流中沙粒粒度沿垂向变化为细沙增加,中沙减少,沙粒平均粒径变细。

Study on the wind-sand flow structure in Mu Us sandy land

In this paper we analyzed and calculated the structure of wind-sand flow of perpendicular height range of 0~30cm on the south edge of MU Us Sandy land.The result indicates the total sand transporting rate in 0~30cm height increases with the wind speed increasing,and decreases with height increasing,presenting the power function relation.At each eigh it presents the power function relation or exponential function relation with wind velocity;The sand transporting rate decreases as height increasing with the same wind velocity,presenting the power function relation or exponential function relation with different wind speeds;Absolute transporting rate increases in 0~30cm height with the increase of wind speed and the total sand transporting rate;the changes of relative transport rate are decreasing in lower,layers increasing in upper layers and slightly change in middle layer.The vertical changes of sand grain size in wind-sand flow are fine sands increasing and coarse sands decreasing,the mean size turn to small.