中文摘要：

针对目前黄河三角洲地区存在的土壤盐渍障碍问题，结合电磁感应仪EM38移动测定系统的田间测量，对表征该地区土壤盐分的土壤表观电导率进行了空间变异特征分析，研究了变异函数随样点数量变化的稳健性，并探讨了Kriging插值精度与样点数量之间的关系。结果表明，土壤表观电导率的变异函数表现出多层次叠加的尺度效应，其变异函数较好地符合球状套合模型，短程变异是构成空间异质性的最主要部分。变异函数对样点比例的减少总体不敏感，当样点比例低于10％，变异函数开始发生形变。Kriging插值精度与空间相似性均随样点比例降低呈下降趋势，当样点比例在20％～80％时，Kriging插值精度对样点比例的降低不敏感；在保证得到稳健的变异函数图的前提下，样点比例降至30％，基本不会损失Kriging插值得到的空间分布信息。

英文摘要：

Aiming at the problem of soil salinization existing in the Yellow River Delta at present, spatial variability of soil salinity characterized by apparent soil electrical conductivity was analyzed with the application of mobile sensing system of electromagnetic induction EM38, the robustness and sensitivity of semivariogram to the change of sample quantity was studied, and the relation between Kriging interpolation accuracy and sample quantity was further discussed. Results indicate that nested spherical model was fitted for semivariance of apparent soil electrical conductivity because of the compound scale effect of multilayer spatial structures. Short-range variation was the chief constitute of spatial heterogeneity. Semivariogram was not sensitive to the reduction of sample size as a whole, and semivariogram exhibited deformation when sample size was less than 10%. Kriging interpolation accuracy and spatial similarity both decreased with the reduction of sample size, but Kriging interpolation accuracy was not sensitive to the reduction of sample size when sample size was between 20% and 80%. On the premise of obtaining robust semivariogram, distribution map kriged from 30% sample size of total apparent soil electrical conductivity data almost retained the total spatial information.