西北半干旱区不同防护条件下公路边坡风力侵蚀研究

Research on regular of wind erosion on road slope under different protection in semi-arid area of Northwest China

为了深入了解西北地区公路边坡土壤侵蚀机制,为公路水土保持施工提供指导,选择银川至武汉高速公路固原段为试验地,针对公路边坡的不同防护类型布设土壤侵蚀观测小区,对西北半干旱区新建公路边坡的风力侵蚀规律进行研究。结果表明:公路边坡风蚀强度与风速成显著的对数相关关系;起动风速从大到小依次是六棱砖小区>拱形框架梁小区>机械压实小区>无措施小区;从防风蚀效果来看,六棱砖最好,拱形框架梁次之,机械压实几乎没有效果;六棱砖防护下的坡面相对土壤流失率为0.35,拱形框架梁为0.55,而机械压实达到0.91。

In order to study the mechanism of soil erosion on road and provide the guideline for soil and water conservation in northwest China, experiment sites were located at Guyuan section along Yinchuan to Wuhan highway and several observation plots were selected according to different protection styles of road slope. The regular of wind erosion on a new road slope in semi-arid area in northwest China was conducted. The result shows that there is significant logarithmic relationship between intensity of wind erosion and wind velocity, and sequence of threshold wind velocity is： hexagonal brick 〉 arched frame 〉 compaction by machine 〉 unprotected. Hexagonal brick is the best one for the preventing wind erosion and arched frame take second place, compaction by machine is the worst. The relative soil loss ratio of road slope with hexagonal brick protection is 0.35, and that of road slope with arched frame and compaction by machine are 0.55 and 0.91, respectively.