中文摘要：

为研究褐土坡面径流流速受坡面黑麦草覆盖度的影响,在2个雨强（0.5、1.0 mm/min）和2个坡度（10°、20°）条件下人工模拟降雨,分析研究了5个不同黑麦草覆盖度（0、20%、40%、60%、80%）对坡面径流流速的影响。结果表明：坡面径流流速随降雨历时延长而增加,最后达到稳定流速。坡面流的稳定流速与雨强和坡度呈正相关,与黑麦草覆盖度呈负相关。60%的坡面草覆盖度是一个拐点,高于此拐点时,坡面径流的流速差异较小,且坡度对流速的影响不十分显著。以黑麦草覆盖度拐点为界,分2段拟合了坡面流的稳定流速（V）与草覆盖度（C）、雨强（R）、坡度（θ）的方程：在草覆盖度≤60%时,V=47.75（1-C）0.27（sinθ）0.13R0.56（R2=0.97）;在草覆盖度〉60%时,V=24.15（1-C）0.13（sinθ）-0.01R0.49（R2=0.98）,2段统计关系相关性十分显著。

英文摘要：

To understand the effects of ryegrass coverage on flow velocity at cinnamon soil slope, we analyzed the effects of five different ryegrass coverage （0,20% ,40% , 60% , 80% , respectively） on flow velocity under the condition of artificial rainfall, conducted by two rainfall intensities （0.5,1 mm/min） and two slopes（ 10° ,20°） respectively. The results showed that flow velocity had positive correlation with rainfall duration until reach the stable. Meanwhile, there were positive correlations between stable flow velocity and rainfall intensity as well as slope, while negative correlation between stable flow velocity and coverage of ryegrass grass. When the coverage of ryegrass exceeded 60% , the differences in flow velocity at different conditions declined and the influence of slope on flow velocity was insignificant. Hence, based on the threshold, we simulated the equation into two parts, given by flow velocity （V） , coverage of sloping grass （ C）, slope （0） and rainfall intensity （ R）, when the coverage is ≤60%, V = 47.75 （ 1 - C）°27（sinO）0.13R0.56（R2 =0.97） ; when the coverage is 〉60% , V=24.15（1 - C）0.13 （sin0） -0.01R°49 （R2 = 0.98）. The correlation of the equations is significant respectively.