The sediment concentration of runoff reflects the fluctuation and evolution of the runoff-sediment relationship, and can be used as an important index to evaluate the characteristics of the interactive evolution process of runoff and sediment yield under the influence of vegetation. The influence of different grass covers on sediment concentration of runoff on loess slope under different rainfall intensities and slopes were studied through artificial rainfall experiment. The results showed that:(1) The greater the grass cover, the more delayed the initial time of slope runoff production. The sediment concentration of runoff on slopes covered with grass fluctuated in the beginning 15 min of rainfall, but showed a decreasing trend on the whole, and then reached a stable state, and the sediment concentration of runoff on the slope covered with grass was significantly lower than that on the bare land. (2) The average sediment concentration of runoff increased with the increasing of both rainfall intensity and slope, and the responses of average sediment concentration to both rainfall intensity and slope could be described by power function equations, with R2 ranging from 0.823 to 0.974 and 0.880 to 0.971, respectively. The average sediment concentration decreased with the increasing of coverage, and the influence of rainfall intensity on the average sediment concentration weakened with the increasing of coverage. The response of average sediment concentration to coverage could be described by linear equation with R2 ranging from 0.732 to 0.979. (3) The response of average sediment concentration to coverage and rainfall intensity (R2=0.822, NE=0.921, p<0.01), coverage and slope (R2=0.975, NE=0.697, p<0.01) could be described by binary power function equation. And the comprehensive response of average sediment concentration to coverage, rainfall intensity and slope could be described by a ternary linear equation (R2=0.771, NE=0.774, p<0.01). Among them, the model based on coverage and rain intensity and the model based on coverage, rain intensity and slope had the best fitting effect. The degree of influence on sediment concentration followed the order of coverage>rain intensity>slope. The results could provide references for the research of change characteristics and mechanisms of sediment concentration on loess slope, and have important significance for soil and water loss control and sustainable development of ecosystem on the Loess Plateau.
崔钦凯, 刘俊娥, 陈浩, 周正朝.草被覆盖、雨强和坡度对黄土坡面径流含沙量的影响[J].水土保持学报,2023,37(5):40~47复制