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揭示坡面水流水动力参数特征对于深入了解坡面土壤侵蚀的内在机制具有重要意义.本试验在黄河下游河岸带原生坡面上,采用野外模拟径流冲刷的方法,研究了4个坡度(5°、10°、15°、20°)和3个植被盖度(0%、15%、30%)在特定放水量(15 L·min~(-1))条件下坡面薄层水流剥蚀土壤的水动力学过程,分析了径流剪应力(τ)、水流功率(ω)、径流能量(F)等水动力学参数的变化及其对坡度、植被盖度以及二者交互作用的响应差异.结果表明:在坡度和植被盖度的影响下,τ、ω和F变化规律明显,坡度不变情况下,τ随着植被盖度的增加而增加,ω和F随着植被盖度的增加而减小;植被盖度不变情况下,τ、ω和F均随坡度的增加而增加.坡度小于10°时,坡度和植被盖度的变化对坡面土壤侵蚀的影响不明显;坡度大于10°时,相同坡度条件下植被盖度越大减蚀效果越明显,相同植被盖度下坡面侵蚀量随坡度的增大而增加.τ、ω均与土壤剥蚀率呈显著的线性关系,在土壤侵蚀发生时均存在临界剪应力和临界功率;F与土壤剥蚀率则呈现良好的对数关系.双因素方差分析表明,坡度和植被盖度对τ、ω和F的影响显著,两者的交互作用对ω影响显著,但对τ、F的影响不显著.
Revealing the characteristics of hydrodynamic parameters of slope water flow is of great significance for understanding the inherent mechanism of slope soil erosion.In this study, the simulated runoff scouring on the natural slope of the riparian zone of the lower Yellow River, (10%, 15 °, 20 °) and three vegetation coverage (0%, 15%, 30%) under the condition of 15 L · min ~ (-1) The hydrodynamic parameters such as runoff shear stress (τ), water flow power (ω), runoff energy (F) and other hydrodynamic parameters were analyzed and their differences in response to slope, vegetation coverage and their interaction were analyzed. The results showed that under the influence of slope and vegetation coverage, the changes of τ, ω and F were obvious. Under the condition of the same slope, τ increased with the increase of vegetation coverage, and ω and F increased with the increase of vegetation coverage Decreases, while τ, ω and F increase with the increase of slope.When the slope is less than 10 °, the effect of slope and vegetation coverage on soil erosion is not obvious.When the slope is more than 10 °, the more the vegetation coverage under the same slope condition is, the more obvious the erosion effect is, and the erosion amount under the same vegetation coverage And slope increased, τ and ω both showed a significant linear relationship with soil erosion rate, both critical shear stress and critical power existed when soil erosion occurred, and F had a good logarithmic relationship with soil erosion rate. Analysis of variance showed that the effects of slope and vegetation coverage on τ, ω and F were significant, and the interaction between the two had a significant effect on ω, but the effect on τ and F was insignificant.