库布齐沙漠HDPE网和植物纤维网沙障防沙试验效应

The Sand-prevention Effects of HDPE Net and Plant Fiber Net Sand Barriers in the Hobq Desert

在库布齐沙漠流动沙丘区建立HDPE网和植物纤维网工程沙障试验区,采用MetOne 014A/024A型8通道风速仪、8方位集沙仪、风蚀插钎,观测试验沙障影响下的风速、输沙量和地表侵蚀堆积,对比分析不同规格HDPE网、植物纤维网方格沙障和HDPE网前沿高立式阻沙沙障的防风固沙效应。结果表明:(1)一定孔隙度(50%)的方格沙障中心风速垂直变化幅度与变化规律,仅与沙障平面规格和高度(h)密切相关,与试验材料基本无关。相同平面规格的方格沙障,高度(h)大者降风效应显著;相同高度的方格沙障,小规格降风效应较为显著;(2)试验沙障及其防沙体系对风沙流输沙产生明显影响,相近地貌部位,5.0m×5.0m(h=100cm)植物纤维网方格中心输沙量远小于1.0m×1.0m(h=20cm)HDPE网方格和流动沙丘区,大规格高立式沙障固沙效应优于小规格低立式沙障;(3)试验沙障的地表侵蚀堆积状态仅与沙障规格有关,沙障材料的影响不明显。

We established an experimental area of new materials of HDPE net and plant fiber net sand barriers in the shifting sand dune area of the Hobq Desert.The MetOne 014 A/024 A8 channels anemometers,8 channels sand collectors and the steel drills were used to observe the vertical velocity distribution,amount of sediment transport,erosion and accumulation intensity near the surface under the influence of the new material sand barriers with different specifications.The fixing efficiency was comparatively analyzed among different specifications of the HDPE sand barriers,plant fiber sand barriers and the vertical sand blocking fences.The results show that：（1）The wind speed variation in the center of barriers with50%porosity is only closely related to the sand barrier plane specifications and the exposure hight（h）rather the test materials.Given the same plane specification,the higher the exposed height（h）is,the more obvious amplitude of velocity reduces;With the same exposed height（h）of the sand barriers,the sand barriers with the small size have a more significant effect of reducing wind.（2）The sand barrier and the sand control system have a significant effect on the wind-blown sand transport;the wind-blown sand transport in the center of the 5 m×5 m（h=100 cm）plant fiber net checkerboard sand barriers is far less than the 1 m×1 m（h=20 cm）HDPE checkerboard sand barriers at the shifting sand area.The sand fixing effect of the large size sand barriers is better than the small size sand barriers;（3）The erosion and deposition of the sand barriers＇surface is only related to the specification and no correlation with the materials.