不同覆沙方式下的坡面侵蚀产沙特性研究

Characteristics of slope erosion and sediment yield under different sand cover modes

文中利用室内模拟降雨技术,通过不同覆沙方式和不同降雨强度的组合试验,对坡面侵蚀产沙特性进行了研究。得到结果:坡面初始产流时间基本随雨强的增大而提前。坡面覆沙后侵蚀量增多,且侵蚀量随雨强的增大而增大,半覆沙坡面的产沙量是全覆沙坡面的1.06~2.48倍。0.5、1.0mm/min雨强时半覆沙坡面产沙高于无覆沙坡面,1.5mm/min雨强时低于无覆沙坡面,而半覆沙坡面产沙则均高于全覆沙坡面。全覆沙破面含沙量受雨强影响较小,减沙效果较稳定。试验结果表明,坡面覆沙可以有效延迟初始产流时间;坡面覆沙后侵蚀程度增强,且随降雨强度的增大而增大,半覆沙坡面侵蚀程度高于全覆沙坡面;无覆沙坡面受降雨强度影响较大。文中为研究风水复合侵蚀提供了数据支撑,以期为揭示黄土坡面侵蚀发生机理和水土流失规律提供一些参考。

In this paper,the characteristics of slope erosion and sediment yield were studied by using indoor rainfall simulation technology and combined experiments with different sediment cover methods and different rainfall intensities.The results show that the time of initial runoff generation on the slope basically advances with the increase of rainfall intensity.The amount of erosion increases while the slope is covered with sand,and the amount of erosion increases with the increase of rainfall intensity.The sediment yield of the semi covered slope is 1.06~2.48 times of that of the fully covered slope.When the rain intensity is 0.5mm/min and 1.0mm/min,the sediment yield of the half sand covered slope is higher than that of the non sand covered slope,and when the rain intensity is 1.5mm/min,it is lower than that of the non sand covered slope,while the sediment yield of the half sand covered slope is higher than that of the full sand covered slope.The sediment concentration of the whole covered sand break is less affected by rainfall intensity,and the sediment reduction effect is relatively stable.The experimental results show that the initial runoff generation time can be effectively delayed by sand covering on the slope.The erosion degree of the slope covered with sand increases with the increase of rainfall intensity,and the erosion degree of the slope covered with half sand is higher than that of the slope covered with all sand.The slope without sand cover is greatly affected by rainfall intensity.This paper provides data support for the study of wind and water combined erosion,with a view to provide some reference for revealing the mechanism of loess slope erosion and the law of soil and water loss.