沧州三县表层土壤全氟空间变异特征分析

Study on Spatial Variability of Surface Soil Total Fluorine from Three Counties in Cangzhou City

采用GIS与地统计相结合的方法对沧州地区献县、泊头、沧县表层土壤全氟的空间变异特征进行了分析。结果表明:献县和泊头全氟经对数转换后符合指数模型;沧县全氟经对数转换后符合球状模型。献县全氟具有很强的空间相关性,说明受水文地质等自然的结构性因素影响较大;泊头、沧县全氟具有中等的空间相关性,说明由人类活动等随机性因素引起的空间异质性起很大作用。用Kriging内插法对未测点全氟进行最优估计,并形成插值图,可更直观的反映出研究区内土壤全氟的空间变异特征。

Spatial variability of surface soil total fluorine from Xianxiang, Botou and Cangxian was studied by using GIS technique and geostatistical analysis. The results showed that the semivariograms for logarithm conversion value of total fluorine from Xianxian and Botou were fitted by exponential model, while semivariogram for logarithm conversion value of total fluorine from Cangxian was fitted by spherical model. The spatial variability of total fluorine from Xianxian was primarily controlled by structural factors of stream and physiognomy styles, whereas variabilities of total fluorine from Botou and Cangxian were affected by random factors such as human activities. The Kriging method was applied to estimate the unobserved points and their contour maps were obtained. The spatial variabilities of total fluorine in the study area could be reflected clearly in the maps.