中文摘要：

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.

英文摘要：

Revealing the hydrodynamic characteristics is essentially important for understanding the internal mechanism of slope soil erosion. Through a series of simulated runoff scouring experiments conducted in riparian zones of the lower reaches of Yellow River, this paper studied the hydrody- namic process of soil erosion with overland flow on riparian slopes under four different slope gradi- ents （5°, 10°, 15°, 20°） and three levels of vegetation coverage （0%, 15%, 30%） at the same scouring inflow rate （ 15 L ·min-1 ） , meanwhile, we analyzed the changes of the hydrodynamic pa- rameters, including the flow shear stress （T）, stream power （to）, and unit flow energy （F）, and their responses to slope gradient, vegetation coverage and their interaction effects as well. The re- suits indicated thatτ, ω and F showed clear change rules under the effects of slope gradient and vegetation coverage. With fixed slope gradients, ω increased while ω and F decreased with the in- crease of vegetation coverage. Nonetheless, τ, ω and F all increased with the growth of slope gradi- ent under the same vegetation coverage. The effect of changes in both slope gradient and vegetation coverage on soil erosion was insignificant on the slope less than 10°, while the effect of vegetation coverage on reducing soil erosion rate was obvious on the slope more than 10°. Similarly, the slopesoil erosion yield aggravated significantly with the increase of slope gradient under the same vegeta- tion coverage. Moreover, the soil erosion rate showed a good linear relationship with both τ and ω, and they both had critical flow shear stress erosion process. F showed a good logarithmic factor variance analysis, the effects of slope significant, while their interaction effect was and threshold stream power throughout the whole soil relationship with soil erosion rate. Based on the double gradient and vegetation coverage on τ, ω and F were significant only on ω, and insignificant on τ and F.