利用地统计学方法研究了沈阳市细河流域表层土壤中Hg、Cd、Pb和Zn含量的空间结构及其分布特征。结果表明,土壤中Hg、Cd、Pb和Zn的平均含量均高于其背景值;土壤Cd和Zn含量属中等程度的空间相关,Hg和Pb属于空间弱相关,其空间变异均为随机性因素和结构性因素共同作用的结果,但Cd和Zn含量主要受结构性因素影响,而Hg和Pb主要受随机性因素影响。土壤中Hg、Cd、Pb和Zn空间分布特征表明,4种重金属含量在上游较高,顺流而下含量明显下降;土壤中Hg和Pb含量最大值在四方台地区,Cd和Zn含量最大值分布在甘官和富官一带。细河流域土壤Hg、Cd、Pb和Zn含量空间分异是污水灌溉、固体废弃物堆放、农业生产及交通尾气等因素综合作用的结果。
Spatial distribution and pattern of Mercury (Hg), Cadmium (Cd), Lead (Pb) and Zinc (Zn) contents in the soil of Xihe watershed in Shenyang were analysed using geostatistical methods. Results showed that Hg, Cd, Pb and Zn contents in the soil were higher than their background values. Semivariogram models showed that Cd and Zn contents in the soil were moderately auto-correlated and the contents of Hg and Pb had a low level of auto-correlation, which resulted from stochastic and structural factors. However, Cd and Zn contents were mainly affected by structural factors, and Hg and Pb contents were affected by stochastic factors. Also, the distribution maps showed that the contents of Hg, Cd, Pb and Zn were lower along the lower reach of the river. The maximum Hg and Pb contamination were found around Sifangtai area and the maximum accumulation area of Cd and Zn appeared mainly in Ganguan and Fuguan areas. The different distribution pattem of Hg, Cd, Pb and Zn in Xihe watershed were the synthetic results of wastewater irrigation, solid waste dispose, agricultural production and traffic effluent gases.