中文摘要：

水分或溶液在土体中的迁移具有空间和时间上的异质性。以植被发育斜坡云南昭通头寨沟和昆明呈贡段家营为研究试验区,分别运用亚甲基蓝和罗丹明B溶液进行了多次染色示踪渗透试验,发现根-土间隙的导流现象十分明显,其导流作用很可能已经超过了传统的三类土体大孔隙。然而,国内外研究者对根-土间隙方面的研究还比较欠缺。为此,对根-土间隙宽度为0.5-3.0 mm,步长为0.5 mm流道内单相流体摩擦阻力系数和入渗速度进行了理论计算,并讨论了在同一流道和不同间隙流道内影响水分下渗速度的因素,结果表明：根-土间隙的大小对根-土间隙通道内流体的流动特性有着重要影响,随着间隙的减小摩擦阻力系数也相应减小;间隙对流动阻力系数的影响还依赖于Re的大小,其影响随Re的减小而减小。在昭通头寨植被发育斜坡土体中,根-土间隙宽度主要集中在0.5-1.0 mm,间隙内水分下渗的速度分布在区间0.014-0.203 mm/s;相同面积上,头寨试验区渗透速率是呈贡段家营试验区的26.28倍。由于根-土间隙的存在,大大地促进了土体水分的快速下渗,对滑坡孕育的贡献是显著的。

英文摘要：

The moisture or solution migration in soil with heterogeneity in space and time. This paper based on the distribution and vegetation development test area of Touzhai Gully（ in Zhaotong of Yunnan, China） and Duanjiaying （ in Cheng＇ gong of Yunnan, China） as the research background, In the experimental area, respectively using methylene blue and rhodamine B solution dyed tracer penetrant test many times and found that the diversion phenomenon is very obvious,the diversion function is likely more important than the traditional three kinds of soil macropore, however, the research of soil-root interstice is relatively lacking at home and abroad. The theoretical calculation was performed to predict the speed of the fluid and the flow characteristics for the developed flow in soil-root interstice with the gap size of 0.5 - 3.0 mm, the step length is 0.5 mm. The calculation results are in good agreement with experimental data. In addition, the gap size of the soil-root interstice has great impact upon the flow characteristics. The decrease of the gap size reduces the friction factor, and discussed the influence factors of water infiltration in the same channel and different interstice width . The results show that the higher the Reynolds number, the larger the effect of the gap size upon the friction coefficient during single-phase flowing through the soil-root interstice ; the effect of the gap size upon the friction coefficient depends on the Reynolds number, and will decrease with the decrease of the Reynolds number. The soil-root interstice width of vegetation development in soil slope are mainly concentrated in 0. 5 -1.0 mm in Touzhai ,the speed of water infiltration is the range of 0. 014 -0. 014 mm/s. On the same area, the infiltration rate of Touzhai Gully test area is 26.28 times to Duanjiaying test area. The existence of soil-root interstice, greatly promoted the rapid infiltration of the soil moisture, the results show that the contribution of soil-root interstice macropore to the landslide preparati