天山北坡土壤重金属含量的分布特征及其来源解释

Distribution characteristics of soil heavy metal content in northern slope of Tianshan Mountains and its source explanation

  • 摘要: 以天山北坡巴里坤 伊吾、新源 巴音布鲁克和昭苏 特克斯3个区段为研究区域, 利用新疆土壤背景值、土壤环境质量二级标准(GB15618-1995)、单因子污染指数法和内梅罗综合污染指数法对不同区段土壤重金属含量进行污染评价, 应用多元统计分析方法对不同区段之间的土壤重金属含量及其污染指数进行定量比较, 分析并阐明不同区段土壤重金属含量的分布特征及其污染来源。结果表明: 天山北坡巴里坤 伊吾区段各重金属(Cr、Cu、Ni、Pb、Zn)含量的平均值及其单因子污染指数和综合污染指数比新源 巴音布鲁克区段、昭苏 特克斯区段高, 新源 巴音布鲁克区段的比昭苏 特克斯区段高。巴里坤 伊吾区段土壤重金属污染程度比新源 巴音布鲁克区段、昭苏 特克斯区段高, 新源 巴音布鲁克区段的比昭苏 特克斯区段高。巴里坤 伊吾区段重金属污染除了受成土母质的影响之外, 还受人为因子(交通、工业和农业、旅游业)的影响, 其中PC1方差贡献率为91.22%; 新源 巴音布鲁克区段土壤重金属污染除了受成土母质的影响之外, 还受人为因子(交通和工业)的影响, 其中PC1方差贡献率为67.58%, PC2贡献率为22.47%; 昭苏 特克斯区段土壤重金属污染主要受成土母质的影响, 此外该区段的农业对其也有一定影响, 其中PC1方差贡献率为47.93%, PC2方差贡献率为29.84%。

     

    Abstract: Pedosphere constitutes an important part of the earth surface and is the base for most lives. Sustaining better quality soil is a prerequisite for healthy ecosystem. In recent decades, however, soil conditions have been heavily affected by rapid agricultural and industry activities. Heavy metal soil contamination and pollution from enhanced human activity have become a major threat to the health of regional ecosystems. As a result, research on heavy metal contamination of soils (e.g., discriminating the sources and evaluating environmental risks of heavy metals) has become a hot-field in geography, pedo-science and environmental science. Located in central Xinjiang Uygur Autonomous Region with relatively plenty rainfall, Tianshan Mountains is an important water source and ecological barrier in China. Variations in ecological and environmental conditions in the mountains have exerted an obvious pressure on the oases in the lower reaches. In August 2011, a field investigation was carried out in order to gain a comprehensive insight into soil heavy metal contamination conditions of Tianshan Mountains. A total of 153 soil samples were collected from three sections - the eastern (Balikun-Yiwu), middle (Xinyuan-Bayinbuluke) and western (Zhaosu-Tekesi)-in that northern slop of Tianshan Mountains. The samples were sent to the laboratory in the Institute of Ecology and Geography, Chinese Academy of Sciences for analysis for heavy metals. Five heavy metals (Cr, Cu, Ni, Pb and Zn) were analyzed using standard methods. Using single factor pollution index and comprehensive pollution index, quantitative comparison was done for soil heavy metal pollution in different sections with the soil background value in Xinjiang and the secondary standard of soil environmental quality (GB15618-1995). Moreover, the distribution features and pollution sources of soil heavy metals in the different sections were analyzed and illustrated using principal component analysis. The results showed that soil heavy metal content and the related single factor pollution index and comprehensive pollution index for the eastern section of the northern slope of Tianshan Mountains (Balikun-Yiwu) were higher than those in the middle (Xinyuan-Bayinbuluke) and western sections (Zhaosu-Tekesi). The soil heavy metal pollution level in the middle section was higher than that in the western section. Heavy metal pollution in the eastern section of the northern slope (Balikun-Yiwu) was caused mainly by human factors such as traffic, industry, agriculture, tourism. Although human factors (traffic and industry) had some effects, soil heavy metal pollution in the middle section (Xinyuan-Bayinbuluke) was mainly from soil parent materials. In the western section (Zhaosu-Tekesi), soil parent materials were main resources of soil heavy pollution with some effects from agriculture.

     

/

返回文章
返回