干旱区生态环境知识资源中心

Coupling relationship between soil magnetism characteristic and soil heavy metal is one of the hottest topics of current environmental study. Bosten Lake is a major freshwater lake in arid region of Xinjiang, which plays a vital role in regulating this regional ecosystem. In order to explore the soil magnetic susceptibility, soil heavy metal characteristics as well as the correlation between them, in this paper, we selected 10 soil profiles along north shore of Bosten Lake for the determination of soil magnetic susceptibility, and heavy metal content. Through statistic analysis, we can see that: (1) Low frequency magnetic susceptibility of soil along north shore of Bosten Lake gradually increases with the depth of soil layer from 0 to 60cm, and gradually increases to the top value within the soil depth range of 40-60cm, while gradually decreases with the soil depth from 60 to 100cm; According to the variation of magnetic susceptibility content in different soil layers, we can see that within the soil layer with depth range from 0-20cm, 20-40cm, 60-80cm, 80-100cm, it exhibits the intermediate variation, while in the soil layer from 40-60cm, it shows the strong variation. Based on the average value of frequency-dependent magnetic susceptibility, we can see that there are less supper paramagnetic particles within soil layer with depth of 20-40cm, while in other soil layer, the supper paramagnetic particles contents are all over 10%. The analysis result of variation coefficient shows within 20-40cm soil layer, it exhibits medium variation, and in other soil layers, it exhibits strong variation. (2) The content order of heavy metal in soil along the north shore of Bosten Lake is Mn>Cr>Zn>Cu>Ni>As>Pb>Hg, and the vertical distribution rule is that the element Cr and Mn contents gradually increase with the deepening soil layer range from 0-80cm, while gradually decrease with the deepening soil layer range from 80-100cm; There is no obvious change occurring to the Cu content in all soil layer; contents of other elements in 20-40cm soil layer are all lower than that in 0-20cm soil layer. The variation rule of heavy metal content is that Cu, Ni, Pb, Zn, As, Cr show the medium variation, while the Mg and Hg show strong variation. (3) The relation characteristics between heavy metal content and magnetic susceptibility of soil along the north shore of Bosten Lake: the contents of Cu, Mn, Pb, Hg are positively correlated with the low frequency magnetic susceptibility, wherein the Cu element content is related with low frequency magnetic susceptibility in largest degree; Contents of Cr, Pb, Cu, Ni, Zn, Mn are positive correlated with frequency-dependent magnetic susceptibility, wherein the correlation between contents of Mn and Cu elements are mostly and frequency-dependent magnetic susceptibility is the biggest. By above analysis, we can provide scientific reference to regional environmental governance and protection.