论文部分内容阅读
田块尺度土壤特性的空间变异性对水分与溶质运移具有明显的影响。该研究在野外 3 0 m× 3 0 m面积、土壤类型为砂壤土的田块的 10 0个空间点上 ,分别利用张力计和取土样室内测定的方法测定了 3 0 cm土层深处土壤水张力、土壤容重ρ、饱和含水率θs,与初始含水率θi,同时利用圭尔夫仪 ,测定了该田块同样深度 10 8个空间点上的饱和水力传导度 Ks与孔隙大小分布参数α。利用经典统计分析与地质统计分析方法分析上述参数的空间变异特征 ,研究结果表明 :ρ,θi,θs,Ks和容水度 C遵从正态分布 ,而α具有对数正态分布 ;Ks,α和 C具有较大的空间变异性 ,而ρ和θs的空间变异性则较小 ;Ks和logα是空间统计相关的 ;土壤水张力的空间变异具有时不变特征 ,且土壤水张力方差是其均值的二次函数
The spatial variability of soil characteristics at field scale has a significant effect on the transport of water and solute. The study was conducted on 10 0 spatial points of fields with 3 0 m × 3 0 m fields and sandy soil types in the field. Tensiometer and soil sampling were used to determine the depth of the 30 cm soil layer Soil water tension, soil bulk density ρ, saturated water cut θs, and initial water cut θi, and the saturation hydraulic conductivity Ks and pore size distribution parameters at the same depth of 10 8 spatial points of the field were measured by using Guelph apparatus α. The results show that ρ, θi, θs, Ks and water content C follow the normal distribution and α has a logarithmic normal distribution; Ks, α And C have larger spatial variability, while ρ and θs have less spatial variability; Ks and logα are statistically related to space; the spatial variability of soil water tension has time-invariant features and the variance of soil water tension is Quadratic function of the mean