泊头市重金属元素空间变异规律研究

采用GIS与地统计相结合的方法对泊头市表层土壤(0～20 cm)全量Zn、Cu、Pb、Hg、Cr、Cd、Ni、As 8种重金属的空间变异特征进行了分析。结果表明:从相关系数来看,8种重金属中除Hg以外,其它重金属在研究区内都呈现显著的正相关关系,土壤数据中除了全AS属于正态分布,其余元素数据经对数转换后符合正态分布,通过元素的块金效应分析,元素Ni和Cr在研究区的空间相关性最为强烈;用Kriging内插法对8种重金属进行最优估计,从空间插值图可以直观地看出,某些地区重金属含量由于受到人类活动的影响表现出局部的异常性,中东部大于西南部,主要集中在洼里王镇和王武庄乡、郝村乡,其它乡镇相对含量较低,这一方面受河流影响,重金属在水中难存留,另一方面就是东部工业发达,因此受到的重金属污染可能较大。

Study on the Spatial Variability Law of the Heavy Metals in Featured Agricultural Growing Areas in Botou

The paper made an analysis on the spatial variability character of eight heavy metals total volume in Botou’s surface soil,Zn,Cu,Pb,Hg,Cr,Cd,Ai,As,by the Geostatistics method combined with the GIS,and gave a forecast on the partition of the organic green agricultural products base.The results showed that in Botou’s surface soil the as total volume belongs to the normal distribution,and other element belong to the normal distribution with a logarithmic transform.In the view of variation coefficient,Cr had the minimum variation coefficient of 5.68%,and the Hg had the max variation coefficient of 36.19%.In the view of correlation coefficient,the Hg,Cr and Cd had no significant correlation.The Hg and As had a significant minus correlation by 1%.Other elements had a significant correlation by 1%within the study Area.Via the nugget effect analysis of the elements,the Ni and Cr had the most intensity spatial correlation,while the Cu,Hg,Cr have the longest change process of 57 290.4 m,which meant these elements had a close relationship with the soil parent material,and the Pb had the shortest change process of 14 380.6 m which meant the distance of the Pb spatial autocorrelation was longer than the sampling interval distance of this element.The spatial interpolation picture directly showed that there was some partial abnormity in the volume of the heavy metals in some area caused by the human activity,in the central and eastern the volume of the heavy metals was high while the southern was low.Besides the parent material and other natural factors,the heavy metal residues caused by human activities such as traffic exhaust and pesticides and fertilizers was the main reason of the heavy metals spatial variability.