金华市土壤磁化率与重金属的空间变异特征

工业化、城市化的进程对城市土壤产生了巨大的环境压力。以浙江省金华市为典型区,采用地统计学方法对表层土壤的磁化率和Cr、Co、Ni、Cu、Pb等5种重金属结构特征和空间分布格局进行了分析,并从空间上寻找磁化率与重金属的关系。结果表明,(1)低频磁化率总体较低,频率磁化率总体偏高,都属于强变异,两者呈负相关。重金属Cu、Pb、Ni含量大多在土壤背景值之内,Cr、Co则有较多土样超过背景值。(2)从总体上看,磁化率与5种重金属相关性较弱。(3)低频磁化率、Pb、Co具有很强的空间相关性,频率磁化率、Ni、Cu具有中等的空间相关性,Cr的空间相关性较弱。(4)在空间上,低频磁化率与频率磁化率负相关明显;在城区西部和西北部,重金属Cr、Ni、Pb、Cu含量均相对较高,在城市中心,重金属Pb、Cu含量较高;Cr、Co与低频磁化率从空间上更多地表现出负相关,Co与频率磁化率在空间上正相关较明显。

Spatial Variability of Soil Magnetic Susceptibility and Soil Heavy Metals in Jinhua City

Industrialization and urbanization has produced a huge environmental pressure on the urban soil. Jinhua in zhejiang province is been choosed as the typical area, the structure characteristics and spatial distribution pattern between the surface soil magnetism, 5 kinds of heavy metal Cr, Co, Ni, Cu and Pb were analyzed by mean of geostatistics method, and then looking for the relationship between magnetism susceptibility and heavy metal from the space. The results show that first, magnetic susceptibility is generally low, frequency magnetism susceptibility is high overall, both of them are strong variation, they are negatively correlated. The content of Cu, Pb and Ni are mostly in the soil background value, there is more soil samples which its content of Cr, Co is more than the background value. Second, all in all, the correlation between magnetic susceptibility and 5 kinds of heavy metal is weaker. Third, the magnetism, Pb, Co have very strong spatial correlation, frequency magnetic susceptibility, Ni, Cu have medium space correlationand but the spatial correlation of Cr is weaker. Finally, in the space, magnetic susceptibility is negatively related to the frequency magnetism susceptibility obviously; In the west and northwest of the city, the content of Cr, Ni, Pb, Cu are relatively high, in the city center, the content of Pb, Cu is higher; Cr, Co and magnetic susceptibility shows negative correlation in the space, the positive correlation between Co and frequency magnetic susceptibility is obviously in space.