【摘要】 为科学治理工程开挖坡面水土流失问题,采用野外人工模拟降雨试验,设计了5种雨强(30,60,90,120,150 mm/h)和3种坡度(10°,20°,30°),系统分析了不同情景下雨强、坡度、径流率、径流流速、水流剪切力及水流功率同坡面剥蚀率之间的关系。结果表明:工程开挖坡面剥蚀率Di与坡度S相关性不显著(p> 0.05),与雨强I、坡度和雨强的交互作用(I×S)呈极显著相关(p <0.01);采用3种常用的细沟间侵蚀模型来计算工程开挖坡面土壤剥蚀率,就拟合效果而言,幂函数型坡度因子指标更适用于工程开挖坡面土壤剥蚀率的计算;采用径流流速、水流剪切力和水流功率为代表的水动力学参数来计算土壤剥蚀率,就拟合效果而言,水流功率是描述其细沟间侵蚀动力过程的最理想水力参数。研究成果可为建立工程开挖坡面水土流失量预测模型提供技术参数和依据。更多还原

【Abstract】 In order to control soil and water loss on excavated slope in a scientific manner,we conducted artificial simulated rainfall field experiment by setting up five rainfall intensity levels( 30,60,90,120,150 mm/h) and three slope gradients( 10°,20°,30°). We systematically investigated the relationship between excavated soil slope erosion rate and rainfall intensity,slope gradient,runoff rate,flow velocity,shear stress and stream power under different scenarios. The results show that there is no significant correlation between excavated soil slope erosion rate and slope gradient with 95% confidence interval; however excavated soil slope erosion rate is strongly correlated with rainfall intensity,and the combination effects of slope gradient and rainfall intensity( I x S) with 99% confidence interval. The excavated soil slope erosion rate is calculated using three common inter-rill erosion models,and power function slope factor is more applicable in terms of the simulation effects. Hydrodynamic parameters used in calculation include runoff velocity,shear stress and stream power,and stream power appears to be the ideal parameter for describing dynamic process of inter-rill erosion.更多还原