重庆耕地土壤重金属Hg、Cr含量的空间变异性研究

在兼顾重庆三峡库区耕地土壤类型与样点分布相对均匀性的前提下,对重庆三峡库区内39个县区耕地的455个观测点取样分析,测定了代表不同土壤类型耕地的Hg、Cr重金属含量,并应用地统计学的方法分析了数据的统计特征值和结构特征。结果表明:Hg和Cr服从对数正态分布。拟合得到Hg和Cr的半方差函数模型分别为幂函数和球状模型,Hg、Gr在空间上均存在中等相关性。采用Kriging内插法对未测点重金属进行最优估计,并绘制了Kriging插值图,发现研究区土壤中Cr的含量受局部的随机性因素影响程度较大。

Study of Spatial Variability of Soil Heavy Metals Hg,Cr Content in Chongqing

Content of Hg,Cr were analyzed in 455 soil samplers collected from agricultural field of Three-Gorges Reservior in Chongqing.A geostatistics method was used to analyze the statistical feature of these data.Soil heavy metal Hg and Cr distributed lognormally.The semivariogram model of Hg were power,the model of Cr were spherical.These observed items were correlated in a given spatial range.The Kriging method was applied to estimate the unobserved points and their group map were obtained.The spatial variability of the heavy metals in Chongqing could be reflected clearly in the map.