青藏公路路堤边坡不同草皮铺植形式对水土流失的控制研究

A Study of the Soil and Water Loss Control by Different Ecological Protection Measures on the Embankment Slideslopes of Qinghai-Tibet Expressway

公路建设对于环境的影响在青藏高原高寒高海拔生态脆弱区域十分显著。本研究结合青藏高原多年冻土区公路边坡开展实地径流小区试验,针对应用于青藏高原公路路堤土质边坡的满铺、条铺、散铺三种草皮铺植形式的水土保持效果进行对比研究,研究结果表明在设计集中冲刷流量下,草皮铺植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30%~120%,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草皮铺植形式下的减流减沙效益均出现下降现象,平均减沙效益从37.67%下降到10.20%,平均减流效益从45.02%下降到13.84%。不同冲刷流量下,不同草皮铺植形式的减流减沙效益存在差异,介于10.03%~47.23%,其平均减沙效益大小顺序为:满铺草皮护坡(24.19%)>条铺草皮护坡(23.61%)>散铺草皮护坡(22.96%);平均减流效益大小顺序为:条铺草皮护坡(30.17%)>满铺草皮护坡(28.22%)>散铺草皮护坡(26.62%)。

The highway construction will bring serious soil erosion easily.Based on the ecological and environmental characteristics of the Qinghai-Tibet Plateau and the characteristics of soil erosion spatiotemporal differentiation in slope,this study compared the soil and water conservation effect of three Turf planting forms applied to the soil slopes on the Qinghai-Tibet Plateau by conducting field experiments on slopes.As is shown in the results,the runoff time of the community where measures were taken lengthened in a certain period of time,and its extension range was at 30%~120%.This extension decreased with the increase of the scouring flow.The benefits of flow reduction and sediment reduction of different Turf planting forms all decreased with the increase of scouring flow,among which the average sediment reduction decreased from 37.67%to 10.20%and the average flow reduction decreased from 45.02%to 13.84%.Under different scouring flows,there are differences in the flow reduction and sediment reduction benefits of each Turf planting form,ranging from 10.03%to 47.23%,and the average order of the sand reduction benefits is:full turf slope protection(24.19%)>Strip turf slope protection(23.61%)>Gravel cover slope protection(22.96%);The order of average flow reduction benefits is:Strip turf slope protection(30.17%)>Full turf slope protection(28.22%)>Gravel cover slope protection(26.62%).