漳州市城市绿地表土磁性特征及其环境意义

为揭示土壤磁性物质的来源和成因,对漳州市城区4个不同绿地功能区土壤进行了环境磁学测定,并探讨其环境意义. 结果表明,土壤样品的磁化率(χ)平均值为302.77×10-8 m3/kg,频率磁化率(χ_fd)平均值为1.45%,不同绿地功能区土壤磁化率变化趋势为居住区绿地＞道路绿地＞单位附属绿地＞公园绿地.分析4种绿地功能区的频率磁化率可以得知,公园绿地存在超顺磁颗粒. 对单个采样点进行分析发现,磁化率与频率磁化率呈负相关,饱和等温剩磁(SIRM)和软剩磁(Soft IRM)呈极显著正相关,饱和等温剩磁和硬剩磁(Hard IRM)的相关性不强,表明土壤磁化率的变化主要受亚铁磁性矿物控制,但也存在不完整反铁磁性物质的贡献,土壤磁化率的增强与工业排放、机动车尾气等人类活动有关. 

Magnetic Properties of Surface Soils in Zhangzhou Urban Greenbelts and Their Environmental Implications

In order to determine the source and cause of soil magnetic substances, a detailed magnetic study was conducted in the four different urban greenbelts in Zhangzhou City. The results showed that the average value of magnetic susceptibility was 302.77×10-8 m3/kg, and the χ_fdwas 1.45%. The magnetic susceptibility decreased in the order of residential greenbelt > road greenbelt > accessory greenbelt > park greenbelt. Based on analysis of the χ_fd, SP was found to exist in the soil of the park greenbelt. Analysis of the individual sampling points showed that magnetic susceptibility was strongly and negatively correlated with frequency dependent susceptibility, and there was a significant positive correlation between SIRM and the Soft IRM. However, the correlation between SIRM and the Hard IRM was very weak. These results indicate that the magnetic susceptibility was mainly controlled by ferrimagnetic minerals, with some antiferromagnets also contributing. The enhancement of magnetic susceptibility was correlated with vehicle exhaust, industrial discharge and other human activities.