马卡山不同植被群落斜坡土体中根土环隙导流特性

发布时间：2018-10-15 08:12

【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。
[Abstract]:As a new type of special soil macropore, root soil annulus plays an important role in the process of rainfall infiltration of slope soils developed by vegetation. The slope soil of different vegetation communities with high coverage in Chenggong experimental area was collected. Based on the method of water penetration, the characteristic parameters of macropores were obtained, and the flow conductivity of root soil annulus in soil was studied in combination with the casing mathematical model. The results showed that the annulus size range of root soil in woody and herbaceous vegetation communities was 0.62 ~ 1.02 mm,0.67~1.12 mm, respectively, and the size of each layer of the former was smaller than that of the latter. In both vegetation communities, the maximum value of u/u_m in root soil annulus increased with the increase of depth, but the magnitude was basically the same. In the range of depth, the r value of u/u_m reached the maximum value in each layer of soil. The relative r value of each layer of woody soil is higher than that of herbaceous soil, and the difference of root system and gap size is the main reason for the formation of its characteristics. Under the same flow channel number and Reynolds number, the average velocity, the maximum velocity and the contribution rate of annulus diversion increase with the increase of depth, and the flow rate is vice versa, and the velocity, flow rate and contribution rate of each layer of woody soil are higher than that of herbaceous soil.
【作者单位】：昆明理工大学国土资源工程学院;武汉工程科技学院;昆明理工大学建筑工程学院;云南农业大学建筑工程学院;
【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
【分类号】：S152

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