沙袋沙障凹曲面特性研究

Concave Surface Characteristics of Sandbag Sand Barrier

按不同规格,不同坡位,对设置一年后、总面积近25000m2的沙袋沙障内凹曲面特性进行了调查研究。结果表明,沙障规格和设置部位对沙障凹曲面的特征均有显著影响。通过3种规格的对比,1m×1m规格沙袋沙障更利于稳定凹曲面的形成;3个坡位相比,坡顶处形成的凹曲面较为稳定。不同规格及不同坡位沙障凹曲面的N—S和W—E两个走向垂直剖面轮廓曲线都基本符合一元二次函数,且N—S剖面较W—E剖面陡,表明凹曲面特性受风力及风向影响较大。沙袋沙障稳定凹曲面的障间蚀积系数在1/10左右。障内植物对凹曲面形态特征影响较大,植物具有明显的灌丛堆效应,可进一步增强沙丘的稳定性。大规格的沙障若一定时间内无植被生长,会导致沙障很快失去防护作用。

The concave surface characteristics of sandbag sand barrier of different sizes in different positions of sand dune were studied in this paper. The experimental area is near Jilantai town in the southwest of Ulan Buh Desert. The sand barrier was set in April, 2007 and the investigation of the concave surface was finished in April, 2008. Results show that the sand barrier size and the setting position have strong influences on the concave surface characteristics. Compared with the 3 sizes, the sandbag sand barrier of 1 m× 1 m size is ben- eficial to the stable concave surface formulation. Compared with the 3 positions of the sand dune, concave surface on the top of dune is more stable. All the profile curves of N--S and W--E directions in different types conform to the one variable quadratic function, basically. The N S profile is steeper than the W--E profile. It means that wind strength and wind direction can strongly influence the concave surface characteris- tics. The erosion-deposition coefficient of sandbag sand barrier stable concave surface is about 1/10. The plant in the sand barrier also can influence the concave surface characteristics.