乌兰布和沙漠沿黄段不同治理措施的风沙运移特征及其防护效果

Sand moving characteristics and the protective effect of governance measures along bank of Yellow River in Ulan Buh Desert

为科学治理黄河乌兰布和沙漠沿岸风沙入黄问题,以该河段沿线流沙为对照,开展了麦草沙障、沙柳沙障、葵花杆沙障和梭梭林为代表的工程与植物固沙实验,对不同治理措施下的风速廓线、粗糙度、风沙流结构、防护效果及其相互关系进行了野外观测与室内分析。结果表明：1）各沙障和梭梭林内风速廓线发生改变,近地表风速显著降低,地表粗糙度和摩阻风速显著增加。2）流沙表面输沙量分布随高度增加呈对数递减,90%集中在0-10cm范围,98%分布在0~30m范围内。3）不同措施的输沙率随风速的增加呈增加趋势,但输沙率仅为流沙的1.07%-38.27%,可很好的控制近地表的流沙活动。4）各类固沙措施的实施效果排序葵花杆沙障〉梭梭林〉沙柳沙障〉麦草沙障,控制流沙效果均达到75%以上,对固定流沙均能起到积极作用。综合考虑固沙效果、成本、运输以及使用寿命等,该地区选择葵花杆沙障和梭梭较为合适。该研究结果可为解决风沙入黄问题、完善黄河沿岸风沙防护体系提供参考。

For scientific management of the Yellow River in Ulan Buh Desert section to control the sand along the bank shifting into the river, the engineering and sand -fixation plant experiments, including straw barrier, salix sandy barrier, sunflower stem barrier and Haloxylon ammodendron （ C. A. Mey. ） Bunge, were carried out ; the wind speed profile, roughness, sand flow structure and the protective effects under different control measures, and their relationships were observed and analyzed. Results show that： 1 ） The wind velocity profile changed, near- surface wind speed significantly reduced, surface roughness and friction velocity increased significantly in the barriers and Haloxylon ammodendron forest. 2） The sediment discharge distribution on shifting sand surface showed a logarithmic decrement with height increase; 90% of it concentrated in the range of 0 - 10cm height, 98% of it distributed in range of 0 - 30cm. 3 ） Sand transport rates for different measures increased with wind speed increasing, but the sediment transport rate was only 1.07% -38.27% of the shifting sand; so the meas- ures effectively controlled the sand shifting activity near surface. 4） The sand - fixation effects of all kinds of measures were sunflower stem 〉 Haloxylon ammodendron 〉 Salix psammophila 〉 straw barrier; the shining sand control effects were all of 75% above. Comprehensively considering the sand -fixation effects, transportation costs and service life, etc. , sunflower stem barrier and Haloxylon ammodendron were relatively appropriate for the region.