三峡库区消落带土壤重金属含量变化特征研究

采集三峡库区消落带土壤,对干湿交替运行下消落带土壤重金属迁移转化特征进行研究。结果表明:汛期水体重金属含量明显高于汛后,消落带土壤重金属的迁移转化引起的环境风险较低。消落带土壤Cu和Cr主要以残渣态存在,生态风险较低,Pb和Cd可提取态重金属含量较高,潜在生态风险较大。长期周期性干湿交替运行下消落带土壤重金属含量总体呈现增加趋势,土壤中Cu,Pb,Cd,Cr的含量分别提高了17.04%,24.49%,12.99%及13.70%,总体而言,增大幅度排序为Pb>Cu>Cr>Cd。

Change of Heavy Metals Content in Soil of Water-Level-Fluctuating Zone in Three Gorges Reservoir Area

Taking the soil of water-level-fluctuating zone in Three Gorges Reservoir area as the research object,the features of migration and transportation of the heavy metals in the soil of water-level-fluctuating zone in the condition of alternate drying-wetting are studied.The results indicate that the content of heavy metals in water in flood season is higher than that after the flood season.The environmental risk caused by migration and transportation of the heavy metals in the soil of water-level-fluctuating zone is low.Cu and Cr in soil of water-level-fluctuating zone exist in the form of residue and the ecological risk is low.Heavy metals could be extracted from Pb and Cd,whose potential ecological risk is high.Heavy metal concentration inclines to increase generally in a periodical alternate drying-wetting environment for a long time.The average increasing amount of Cu,Pb,Cd and Cr is 17.04%,24.49%,12.99%,13.70% respectively.In general,the increment sequence is Pb>Cu>Cr>Cd.