坡度和流量对崩积体坡面细沟水流输沙能力的影响

Effects of Slop and Flow on Sediment Transport Capacity of the Colluvial Deposit for Rill Flow in Benggang

为探究坡度及流量对崩岗崩积体土壤坡面细沟侵蚀输沙能力的影响,精确计算细沟水流输沙能力,建立坡面细沟输沙能力因子模型,以崩岗崩积体土壤为研究对象,进行室内水槽模拟试验研究。结果表明:(1)不同流量条件下,坡面细沟输沙能力随坡度的增大而增大,且增幅随坡度的增加而增大,可用一元线性方程表示;(2)不同坡度条件下,坡面细沟输沙能力随着流量的增大而增大,可用幂函数表示;(3)崩岗崩积体坡面细沟输沙能力因子模型为二元幂函数方程,其中流量(q)和坡度(S)的指数分别为1.054和0.617,流量对细沟输沙能力的影响大于坡度;(4)通过模型对比发现,Wu模型、ANSWERS模型及Zhang模型方程都无法很好地预测崩岗崩积体坡面细沟输沙能力。

This study aimed to explore the influence of slope and flow on sediment transport capacity of colluvial deposits for rill erosion,calculate the rill flow sediment transport capacity accurately and establish rill sediment transport capacity factor model.The soil of colluvial deposit was taken as the case and a flume was used to conduct the experiment.The results showed that：（1）Rill flow sediment transport capacity increased with slope gradients at different flow discharge,which could be described by liner equation;（2）Rill flow sediment transport capacity increased with the increasing flow discharge at different slope gradients and the relationship could be described by power equation;（3）Rill flow sediment transport capacity factor model could be described by a dual binary power function,the index of flow rate（q）and slope（S）were 1.054 and 0.617 respectively.The effect of flow discharge was superior to slope gradient in the power function;（4）Compared with Wu model,ANSWERS model and Zhang model,the model of this study was more suitable to predicted sediment transport capacity of colluvial deposits for rill erosion.