植被发育玄武岩斜坡土体大孔隙尺寸及其主要影响因素  

Sizes of soil macropores and related main affecting factors on a vegetated basalt slope

作　　者：官琦[1] 徐则民[2] 田林[2] 

机构地区：[1]昆明理工大学地球科学系,昆明650093 [2]昆明理工大学土木系,昆明650500

出　　处：《应用生态学报》2013年第10期2888-2896,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金-云南联合基金重点项目(U1033601);交通部西部科技项目(200831876723)资助

摘　　要：极端异常气候诱发植被发育斜坡发生滑坡灾害的数量逐年攀升，土体大孔隙产生的优先流对其有重要影响．本文结合水分穿透曲线和Poiseulle方程对马卡山植被发育玄武岩斜坡土体大孔隙的半径范围、数量、平均体积进行估算，分析了该区土体大孔隙分布情况及其主要影响因素．结果表明：研究区域主要植被下土体大孔隙半径在0．3～1．8mm，主要集中在0．5～1．2mm，1．4～1．8mm的大半径孔隙相对较少，而〈1．4mm的小半径孔隙较多．随着剖面发育，大孔隙表现为上部土层多、下部土层少的特点．大孔隙平均体积决定了稳定出流速率84．7％的变异．在影响大孔隙平均体积大小的诸多因素中，植被根系质量密度与其呈线性关系，相关系数为0．70，土壤有机质含量与其呈线性关系，相关系数为0．64．The landslide on vegetated slopes caused by extreme weather has being increased steadi- ly, and the preferential flow in soil macropores plays an important role in the landslide. By using water breakthrough curve and Poiseuille equation, this paper estimated the radius range, amount, and average volume of soil maeropores on a vegetated basalt slope of Maka Mountain, Southwest China, and analyzed the distribution of the soil macropores and the main affecting factors. In the study area, the radius of soil macropores ranged from 0.3 to 1.8 mm, mainly between 0.5 and 1.2 ram. The large-radius maeropores （ 1.4-1.8 ram） were lesser, while the small-radius macro- pores （ 〈 1.4 mm） were more. With the development of soil profile, soil macropores were more in upper layers and lesser in deeper layers. The average volume of the macropores contributed 84.7% to the variance of steady effluent rate. Among the factors affecting the average volume of the large macropores, vegetations root mass had a linear relationship, with the correlation coefficient being 0.70, and soil organic matter content also had a linear relationship, with the correlation coefficient being 0.64.

关 键 词：土体大孔隙 半径范围和数量平均体积水分穿透曲线Poiseulle方程 

分 类 号：P642.2[天文地球—工程地质学]