黄土区被草土质路面产流产沙过程及防蚀效果

通过变坡钢槽装土和人工降雨的室内模拟试验,分析了黄土区裸露土质路和被草土质路(被草土质路种植早熟禾)路面的产流产沙过程及被草土质路的防蚀效果.结果表明:在相同雨强和坡度条件下,研究区被草土质路的径流系数大于裸露土质路;两种路面的径流系数均随着雨强和坡度的增加而增大;不同雨强、相同坡度条件下,径流系数与降雨历时呈对数关系,径流系数与雨强、坡度呈二次函数关系;两种路面的土壤侵蚀速率均随着雨强和坡度的增加而增大;相同降雨条件下,被草土质路的土壤侵蚀速率低于裸露土质路;在不同雨强条件下,被草土质路的平均减沙效益达47.22%;在不同坡度条件下,被草土质路的平均减沙效益达26.24%;被草土质路通过增加路面糙度和增大路面阻力可降低水流搬运泥沙的能力,起到了减少路面产沙量的作用.

Runoff and sediment processes and anti-erosion effects of grass-covered earth road in loess hilly region

A laboratory simulation test with slope-adjustable steel tank and artificial rainfall was conducted to study the runoff and sediment processes of uncovered and Poa pratensis L.-planted earth roads, and the anti-erosion effects of P. pratensis-planted earth road. At the same rainfall intensity and slope, the runoff coefficient of P. pratensis-planted earth road was larger than that of uncovered earth road. For the two kinds of earth roads, their runoff coefficients all increased with increasing rainfall intensity and slope. At the same slope but different rainfall intensity, the runoff coefficient had a logarithmic relationship with rainfall duration, and a quadratic relationship with slope or rainfall intensity. Soil erosion rate increased with increasing rainfall intensity or slope, and was smaller on the P. pratensis-planted earth road at the same rainfall intensity. The average antierosion efficacy of P. pratensis-planted earth road was 47.22% at different rainfall intensity, and was 26.24% at different slope. Because of its higher roughness and higher road surface resistance coefficient, P. pratensis-planted earth road had a lower sediment yield and a decreased sediment transport.