坡面尺度土壤特性的空间变异性

Hillslope-scale Spatial Variability of Some Soil Properties

通过对20m长坡面土壤特性空间变异性的经典统计学分析,结果表明:(1)在同一土壤剖面内,各级粒径含量呈弱变异性,而有机质含量随土层深度的增大而逐渐降低,呈中等变异性;(2)土壤干容重的空间变异性较小,呈弱变异性,但土壤饱和导水率的空间变异性较大,呈中等变异性;(3)水分特征曲线具有一定的空间变异性,比水容量空间变异性较大,呈中等变异性。坡面土壤饱和导水率和干容重的等值线图表明,土壤饱和导水率的变化趋势并不仅仅取决于土壤干容重的相对大小,可能与有机质含量、黏粒含量以及根系分布情况等也有一定的关系。

Spatial variability of some soil properties at a 20 m long hillslope on the Loess Plateau was studied with the classical statistical analysis. The results show that in the same soil profile, sand, silt and clay contents have small variability, and organic matter content decreases from upper layer to lower layer with moderate variability. Soil dry bulk density has small variability, but saturated hydraulic conductivity has moderate one. Soil water characteristic curve has some spatial variability and specific water capacity has moderate one. The isograms of soil saturated hydraulic conductivity and dry bulk density indicate that the change of soil saturated hydraulic conductivity does not only depend on soil dry bulk density, and has some relations with organic matter content, clay content and root distribution.