“城-郊-乡”土壤环境磁学特征及其空间分布研究

为探讨"城-郊-乡"梯度上城市土壤磁性特征及其空间分异规律,对上海市徐汇、闵行、奉贤3区进行系统的磁学测定分析,结果表明研究区土壤磁性明显增强且处于较高污染水平,受外源输入影响较大。土壤磁性主要受低矫顽力软磁性的亚铁磁性矿物控制,磁性矿物颗粒较粗,以多畴MD和粗粒SSD为主。不同磁学参数χ_(lf)、SIRM、χ_(arm)、HIRM呈现相似的空间变化特征,出现明显高值区,分别位于徐汇区北部、闵行区东南和西南以及奉贤区北部和南部。磁性增强高值点均位于工业区,城市土壤磁性增强主要受人类活动中的现代工业活动影响,并以污染型企业为源点使污染范围向外扩散。

Magnetic Properties and Its Spatial Distribution in “Urban-to-Rural”

In order to explore the environmental magnetic properties and their spatial distribution in “urban-to-rural”, this study choose Xuhui, Minhang and Fengxian districts in Shanghai to systematic magnetic analysis. The results show that the soil magnetic enhancement is obvious and is caused by human activities. Soil magnetic properties are mainly controlled by ferrimagnetic minerals with low coercivity and soft magnetic properties. Magnetic mineral particles are relatively coarser, mainly multi-domain (MD) and stable single domain (SSD). χlf, SIRM, χarm, and HIRM showed the similar spatial variation characteristics, the high value area is located in the north of Xuhui District, southeast and southwest of Minhang District, and north and south of Fengxian District. The magnetically enhanced high value points are located in the industrial area. The distribution of the magnetic susceptibility is basically consistent with the layout of the enterprise, and the pollution-type enterprises are used as the source to spread the pollution.