以昆明市呈贡新区马卡山云南松和狗牙根两类典型植被发育斜坡土体为研究对象,采用染色示踪试验研究了水分通过斜坡土体大孔隙网络以优先流形式下渗这一过程。对采集到的剖面染色示踪图像进行处理,得到了土体优先流特征参数的变化规律,结果表明:不同植被发育斜坡土体对降雨的响应是不同的;平均染色面积比和染色路径数量在同一深度不同剖面间以及不同深度处同一剖面间均表现出明显的异质性;除了表层2cm深度范围外,其余深度处云南松发育斜坡土体中平均染色面积和平均染色路径数量比狗牙根的大,说明前者优先流发生和发展较后者活跃。最后,通过对土体中分层根系生物量的测定,发现其与总染色面积比以及染色路径数量随深度增加呈较好的正相关关系,说明斜坡土体中优先流特征与植被根系分布有着密切的关系。
In this study, we take two kinds of vegetated slope soils of the Mountain Maka in Chenggong new district, Kunming municipality as research objects. Dye tracer experiments were used to study the process of rainfall trans- ferring into groundwater through soil macro pore in the form of preferential flow. Collected staining images were pro- cessed to calculated the change regulation of the characteristic parameters of preferential flow. The results showed that there are different response of soil water flow to rainfall in different vegetated slope soils. The staining area ratio and the staining paths amount possess heterogeneity in every profile and obvious in homogeneity between different profiles. Except for the range of 0 -2 cm deep, they in slope soils covered by Yunnan Pine are larger than those covered by Bermuda Grass at the same depth, which can demonstrate that preferential flow of the former is more ac- tive than the latter. In the end, from root weight measuring at intervals of 10cm with depth, we can find out that there is a positive correlation between root biomass and characteristic parameters of dyeing images. It indicates that the characteristics of preferential flow in vegetated slopes has close relation to plant roots.