论文部分内容阅读
[目的]探讨退化梭梭(Haloxylon ammodendron)林和仿真灌木+梭梭灌木林对风沙流的风速、输沙通量及其沙粒的分布影响,为干旱区退化的防风固沙林功能恢复和建立提供参考。[方法]同时测定不同高度下裸沙地、仿真灌木+梭梭林和梭梭林的风速、输沙通量及其沙粒径,比较分析其风速消减率、输沙通量变化及沙粒度随高度分布。[结果]在风速3.0~8.9m/s范围,仿真灌木+梭梭林内的20cm高度的风速平均削减率达到61.35%。梭梭林的输沙通量是仿真灌木+梭梭林的1.5倍,裸沙地平均输沙通量是仿真灌木+梭梭林输沙通量的4.13倍。梭梭林与仿真灌木+梭梭林的输沙通量随高度变化都呈指数递减,其风沙流含沙量及沙粒度的空间变化在10cm以下较大。[结论]仿真灌木+梭梭林降低了林地风沙流中黏粉粒(≤0.02mm)向空气中输送量,改变了风沙流的沙粒度空间结构,迫使风沙流的输沙集中在较低层。
[Objective] The research aimed to discuss the effects of Haloxylon ammodendron forest and simulation shrub + Haloxylon ammodendron shrubs on the wind speed, sediment flux and sand distribution of wind-blown sand flow, and provide the functional restoration and establishment of the degenerated windbreak- reference. [Method] The wind speed, sediment flux and sand diameter of bare sand, simulated shrub + Haloxylon ammodendron and Haloxylon ammodendron at different heights were measured at the same time. The wind speed reduction rate, the change of sediment flux and the grain size of sand With height distribution. [Result] The average wind speed reduction rate of wind speed of 20cm height in the shrub + Haloxylon forest was 61.35% in the range of 3.0 ~ 8.9m / s. The sediment flux of Haloxylon ammodendron was 1.5 times of that of Haloxylon ammodendron and Haloxylon ammodendron. The average sand transport flux of bare sandy land was 4.13 times of that of silt and silos of Haloxylon ammodendron. The sediment transport fluxes of Haloxylon ammodendron and Haloxylon ammodendron forest declined exponentially with height, and the spatial variation of sediment concentration and sand particle size of wind-blown sand was greater than 10 cm. [Conclusion] Simulated shrub + Haloxylon ammodendron decreased the amount of sticky particles (≤0.02mm) in the wind and sand flow in the woodland, changed the spatial structure of sand grain size and forced the sediment transport in the wind-blown sand stream to be concentrated in the lower layer .