西北干旱区农田土壤磁性特征及其环境意义

发布时间：2018-12-14 04:47

【摘要】：为探究环境磁学方法在西北干旱区农田土壤污染监测中的可行性,以典型绿洲农业区张掖市(临泽县、甘州区、民乐县和山丹县)为研究区域,采集农田土壤样品102份并对其进行系统的环境磁学分析.结果表明,张掖市农田土壤磁性特征以亚铁磁性的磁铁矿为主导,磁晶颗粒主要为粗粒假单畴(PSD)和多畴(MD),颗粒等效粒径介于0.2~1μm之间;样品磁化率(χlf)变化范围为22.27×10~(-8)~188.36×10~(-8)m~3·kg~(-1),平均值为63.85×10~(-8)m~3·kg~(-1),磁性矿物含量总体较少但空间变化较大;磁参数空间分布表明,磁性矿物含量在甘州区、民乐县和山丹县高于临泽县,并在甘州区的中部、民乐县的西南边和山丹县的西边呈现相对高值;甘州区中部的磁性高值主要受控于工业生产等人类活动,民乐县西南边和山丹县西边的磁性高值主要与较强的自然成土作用有关.综合多种磁学参数的系统分析能够有效区分和划定农田土壤人为污染范围,为农田土壤污染防治工作提供依据.
[Abstract]:In order to explore the feasibility of environmental magnetic method in monitoring farmland soil pollution in arid area of northwest China, Zhangye City (Linze County, Ganzhou District, Minle County and Shandan County), a typical oasis agricultural region, was used as the research area. 102 samples of farmland soil were collected and systematically analyzed by environmental magnetism. The results showed that the magnetic characteristics of farmland soil in Zhangye city were dominated by ferromagnetic magnetite, and the magnetocrystalline particles were mainly coarse pseudo-single-domain (PSD) and multi-domain (MD), particles with equivalent diameter of 0.2 渭 m. The variation range of magnetic susceptibility (蠂 lf) is 22.27 脳 10 ~ (-8) ~ 188.36 脳 10 ~ (-8) kg~ (-1), the average value is 63.85 脳 10 ~ (-8) m ~ (-3) kg~ (-1). The spatial distribution of magnetic parameters shows that the content of magnetic minerals is higher in Ganzhou district, Minle county and Shandan county than in Linze county, and relatively high in the middle of Ganzhou district, southwest of Minle county and west of Shandan county. The magnetic high value in the middle of Ganzhou district is mainly controlled by human activities such as industrial production. The magnetic high value in the southwest of Minle County and the west side of Shandan County is mainly related to the strong natural soil-forming process. The systematic analysis of various magnetic parameters can effectively distinguish and delimit the range of artificial soil pollution and provide the basis for the prevention and control of farmland soil pollution.
【作者单位】：兰州大学资源环境学院西部环境教育部重点实验室;中国科学院西北生态环境资源研究院;
【基金】：国家自然科学基金项目(41071125) 中央高校基本科研业务费专项(lzujbky-2013-m03)
【分类号】：X53

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