公路弃土场坡面径流的模拟对流域水资源评价和道路侵蚀模型的构建均具有重要意义。通过不同雨强(0.6~2.79mm/min)的人工降雨试验,对不同坡度(19.4%~78.1%)弃土场坡面及坡度为30.6%的弃土场施工道路的坡面径流过程进行了研究。结果表明:在小雨强下(0.6mm/min)径流显著受到土壤干容重及小区坡度的影响,而随雨强的增加,坡度及土壤干容重对径流的影响逐渐被降雨所覆盖。使用Green-Ampt入渗模型可以较为准确地计算公路弃土场坡面径流,模型有效系数达0.975。
Modeling of the runoff process on the slope of highway dump yard plays an important role in watershed water resources assessment and road erosion model construction.In this study,a series of different intensity rainfall processes(0.6~2.79mm/min) are designed and implemented in the lab,and are used to simulate the runoff processes occurred on the different slopes(sloping gradients ranging from 19.4%~78.1%) of highway dump yard as well as its temporary construction road(with a slope of 30.6%).The runoff processes are also simulated by the Green-Ampt(GA) infiltration model.The modeling results show that,when the rainfall intensity is at a low level(such as 0.6mm/min),the runoff yield is significantly affected by the soil dry bulk density and plot sloping gradient;and the effects of dry bulk density and sloping gradient on the runoff yield decrease gradually with the increase of the rainfall intensity.The results also show that the runoff process on the slope of highway dump yard could be accurately predicted by the Green-Ampt infiltration mo-del,with a correlation coefficient of 0.975,particularly when the rainfall intensity is high.