马卡山不同植被群落斜坡土体中根土环隙导流特性  

Flow Characteristics of Root-soil Annulus in Slope Soil Under Different Vegetation Communities

作　　者：郭丽丽[1,2] 曾强[3] 徐则民[3] 张有为[3] 杨继清[4] 

机构地区：[1]昆明理工大学国土资源工程学院,昆明650500 [2]武汉工程科技学院,武汉430200 [3]昆明理工大学建筑工程学院,昆明650500 [4]云南农业大学建筑工程学院,昆明650204

出　　处：《土壤》2017年第1期196-202,共7页Soils

基　　金：国家自然科学基金–云南联合基金重点项目(U1502232;U1033601);高等学校博士学科点专项科研基金项目(20135314110005)资助

摘　　要：根土环隙作为一种新型的特殊土壤大孔隙类型,在植被发育斜坡土体降雨入渗过程中发挥着重要作用。采集呈贡实验区高盖度不同植被群落斜坡土体,基于水分穿透法,获取大孔隙特征参数,结合套管数学模型,进行了土体中根土环隙的导流特性研究,结果表明:木本和草本植被群落土体根土环隙尺寸范围分别为0.62~1.02 mm、0.67~1.12 mm,且前者土体各层环隙尺度均小于后者。两种植被群落土体中根土环隙流道u/u_m的最大值均随深度增加而增大,但大小基本一致;深度范围内,土体各层u/u_m达到最大值时的r值提前,且木本土体各层相应r值均大于草本;根系及环隙尺寸的差异是形成其特征的主要原因。相同流道数量及雷诺数条件下,平均流速、最大流速及环隙导流贡献率均随深度增加而增大,流量则反之,且木本土体各层流速、流量及贡献率均大于草本。As a new type of special soil macropore types, root-soil annulus plays an important role in the process of rainfall infiltration of soil on a vegetated slope. Soils were collected in the high coverage slopes of different vegetation communities in the experimental area of Chenggong, the characteristic parameters of the macropores were obtained by using the moisture breakthrough method, then the flow characteristics of the root-soil annulus were studied combined with mathematical model of annular tubes. Results showed there was little difference between the sizes of the root-soil annulus of the woody and herbaceous vegetation communities, which were distributed in the ranges of 0.62-1.02 mm and 0.67-1.12 mm, respectively, and the annulus scales in different layers in the former vegetation community were smoller than those of the latter. The maximum values of U/Um of root-soil annulus channels in the soils under the two vegetation communities increased with depth, however, the value was nearly the same; within the scope of the depth, the r value was in advance when U/Um of the soil layer reached the maximum value, and the corresponding r values of all layers of woody soil were greater than those of the herb. The differences between the size of root system and the annulus were the main reasons for the formation of the above characteristics. Under the same of the number of fluid channels and Reynolds number, the average flow velocity, maximum velocity and flow contribution rate of the annular increased with depth, however, the situation of flow was opposite. In addition, the flow rate, flow and contribution rate of woody plant soil in each layer were higher than those of herb plant soil.

关 键 词：植被发育斜坡 滑坡 降雨入渗 根土环隙 雷诺数 

分 类 号：S152[农业科学—土壤学]