土壤水张力时变空间结构的初步研究
Preliminary Study on Time Spatial Variability of Soil Water Pressure
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摘要: 通过在永乐店试验站田间安装100支负压计,对田间土壤水张力进行了较长时间的观测。经分析得到土壤水张力的方差是其平均值的二次函数,且方差随平均值的增大而增大。同时通过对不同时间土壤水张力的变差函数的拟合分析,发现模型中基台值随时间的变化最明显,且与张力方差呈现出良好的线性关系;块金值与变程则比较稳定,受时间的影响不大。由此提出了一种反映土壤水张力时变空间结构的变差函数模型。Abstract: The soil-water pressure is measured by 100 individual tensionmeters for a long time in a 30m×30m field with sandy loam soil in Yongledian Irrigation experimental station.Through analysis, it can be found that the relationship between the variance and the mean of the pressure can be described by a quadric function,and the variance increases with the mena of the pressure. Finally, the semivariogram of the soil-water pressure is simulated.