Spatial Variability of Soil Water and Salt in Field and their Estimations by the CoKriging
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摘要: 通过对一块面积为1hm2麦田内的98个观测点取样分析,测定了两个时期的土壤水分和盐分含量。结果表明两个时期的土壤含水量均服从正态分布,底层盐分均服从对数正态分布,而表层的盐分分布具有不确定性。两个时期土壤水分和盐分的变异系数分别属于弱变异和中等变异强度。通过结构分析,发现两个时期的水分和盐分均在一定范围内存在空间相关性。对两个时期土壤水分和盐分空间分布的动态变化进行了比较,同时采用CoKriging方法进行估值,与Kriging法相比,其估计方差减少百分数最大达到了136.3%。Abstract: The soils at ninety-eight observing points by a square of 10×10(m2)were sampled in a wheat field (approximately 1 ha).The mil water and salt of each point in the layers of 0-20cm and 80-100cm were measured at different time.The results indicated that the soil water content under two layers at different time showed a normal distribution,the soil salt content in bottom soil showed a lognormal distribution and the soil salt content in surface soil showed an uncertain distribution.The variability coefficients of soil water and salt respectively belonged to the low and middle intensity.The semivariance analysis was used and found that the mil water and salt were correlated in a given spatial range.Preliminary analysis was made for the spatial dynamic variability of soil water and salt in different time.The Co Kriging method was alms used to estimate soil water and salt content,the estimated variance could be decreased by 136.3% comparing with ordinary Kriging.
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Keywords:
- soil water /
- soil salt /
- spatial variability /
- semivariance /
- CoKriging
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