The heavy metal distribution characteristics in the soil and their evaluation of potential risk were studied based on the research of water-level-fluctuating zone in the Three Gorge Reservoir area. The averages of heavy metals in two banks along the river and different water elevations were found to be above Grade Two of the National Standard for Soil Environment of China, except As which was greater than 19.0mg/kg and Cd, which was greater than 0.38mg/kg. The averages of heavy metals of two banks and between different elevations were different (P<0.1) significantly, and the averages of heavy metals in left bank were greater than the right, but the variation factors of heavy metals of two banks were inversely. Moreover, from upstream to downstream, the averages of all heavy metals except Cd displayed constantly decrease trend along the Yangtze River. The pH and Pb, Cr, Cd, As took on positive correlation(P<0.05 or P<0.01). Cu-Hg, Cu-Cr in soil presented obviously positive correlation (P<0.05). Cu, Pb and Zn, they and other many heavy metals in soil were different (P<0.01) markedly. The potential ecological risk was slight and Cd was the main element which served as a hazard to the ecological environment.%探讨了三峡库区重庆段沿江左右两岸、不同淹水高程消落带土壤中重金属的分布特征,并对研究区域重金属潜在风险进行了评价.结果表明,土壤中As(＞19.0mg/kg)、Cd(＞0.38mg/kg)含量超标,其余重金属含量均达国家土壤环境质量2级标准.沿江两岸Cu、Zn、Cr和Hg含量存在显著差异(P＜0.1),左岸土壤中各重金属平均含量均小于右岸,而右岸各重金属的变异系数较左岸大.不同淹水高程重金属含量差异明显(P.＜0.1).沿长江水流方向,库区土壤中Cd含量先减后增,其余重金属(Cu,Pb,Zn,Hg,As,Cr)含量逐渐降低.Pb和Cr、Cd和As含量与土壤pH值均具有显著相关性(P＜0.05或P＜0.01).土壤中Cu与Hg,Cu与Cr间具有显著正相关关系(P＜0.05);Cu、Pb、Zn与多种重金属间具有极显著正相关关系(P＜0.01).库区消落带土壤重金属潜在生态风险处于轻微状态,主要生态风险元素为Cd.
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