青藏公路边坡不同生态防护措施的水土流失防治效果研究

Study on Soil Erosion Control Effect on Slope of Qinghai-Tibet Highway by Different Ecological Protection Measures

针对应用于青藏公路边坡防护的5种生态措施,通过开展实地径流试验对其水土保持效果进行对比研究。结果表明:采取措施的小区产流时间相对于裸坡均有一定时间的延长,延长幅度介于9%~70%,且随着冲刷流量的增大,这种延长幅度呈减小趋势。随着冲刷流量的上升,不同护坡措施下的减流减沙效益均出现下降现象,平均减沙效益从36.94%下降到4.56%,平均减流效益从42.15%下降到9.65%。不同冲刷流量下,各护坡措施的减流减沙效益存在差异,介于10%~25.77%,其平均减沙效益大小顺序为:三维网植草>满铺草皮>砾石压盖>椰丝纤维毯;平均减流效益大小顺序为:三维网植草>满铺草皮>砾石压盖>椰丝纤维毯。综上所述,5种生态防护措施均能够有效地减少坡面的土壤侵蚀。其中三维网植草护坡的综合效应最好,其次是满铺草皮。

In view of the ecological measures applied to the protection of highway slopes on the Qinghai-Tibet highway, a comparative study of the water and soil conservation effect is carried out. The result shows that(1) Compared with the bare slopes, the runoff generation time of the communities where measures are taken has a certain time extension, the extension range is between 9%-70%, and the extension range shows a decreasing trend with the increase of scouring flow.(2) With the increase in scouring flow, the benefits of flow and sediment reduction under different slope protection measures are all declined, with the average sediment reduction benefit falling from 36.94% to 4.56%, and the average flow reduction benefit from 42.15% to 9.65%.(3) Under different scouring flows, the benefits of flow reduction and sediment reduction of various slope protection measures are different, ranging from 10% to 25.77%. The order of the average sediment reduction benefits is: 3 D mesh grassing> full turf> gravel cover> coconut fiber blanket. The order of the average flow reduction benefit is: 3 D net grass planting> full turf> gravel cover> coconut fiber blanket. In summary, the 5 ecological protection measures can effectively reduce soil erosion on slopes. Among them, the comprehensive effect of 3 D net grass planting slope protection is the best, followed by full turf.