利用变坡度坡沟系统模型和人工模拟降雨试验,定量研究了不同降雨强度下的坡沟系统产流产沙过程,揭示了坡面沟道侵蚀产沙耦合特征。结果表明:坡沟系统累积径流量和累积产沙量与降雨时间呈显著的幂函数关系,随着降雨时间的增大而增大。梁峁坡面来水径流量与沟坡净侵蚀量之间呈幂函数关系,梁峁坡面来水含沙量与沟坡净侵蚀量之间呈反线性相关。从水力学角度对坡沟系统单位水流功率与单宽输沙率的关系进行了分析,得出试验条件下的临界单位水流功率值为0.0043m/s,输沙率随单位水流功率的增大而增大。
Slope-gully system of changeable slope gradients and artificial rainfall experiment was used to study runoff and sediment variation and the coupling mechanism of slope-gully system. The results showed that cumulative runoff and sediment yields of slope-gully system had an obvious positive correlation with rainfall time, which increased with the rainfall time. Upsloperunoff rate had a positive relation with the net sediment of gully caused by upslope runoff Sediment concentration rate of upslope had a negative relation with the net sediment of gully. The relation between the unit stream power and sediment transportation rate was analyzed based on hydraulic theory. The critical unit stream power of 0.0043 m/s under the experiment condition was got and the sediment delivery increased with the stream power.