三峡库区消落带土壤重金属含量特征和污染评价.doc

三峡库区消落带土壤重金属含量特征和污染评价 　　摘 要：以三峡库区蓄水位从175m回落至163m后的云阳段消落带土壤为研究对象，进行重金属Cu、Zn、Pb、Cd和Cr的含量与剖面分布特征及评价研究。结果表明：消落带土壤Cu、Zn、Pb、Cd和Cr的含量分别为58.09mg/kg、108.93mg/kg、15.18mg/kg、0.46mg/kg和71.81mg/kg。重金属剖面分布特征呈规律性变化：0～10cm土层Cu、Cr和Zn含量高于10～20cm土层，而在干湿交替处Zn、Cr含量却表现为0～10cm土层低于10～20cm土层；Pb和Cd剖面分布特征均呈现出0～10cm土层含量低于10～20cm土层，而在干湿交替处呈相反趋势。研究区不受Pb污染，而受Cd、Cu、Zn和Cr不同程度污染，尤以Cd污染最严重，甚至超出三峡库区土壤背景值3倍以上。 关键词：三峡库区；消落带；土壤重金属含量；分布特征；污染评价 中图分类号 X53 文献标识码 A 文章编号 1007-7731（2013）15-16-03 The Characteristics and Assessment of Heavy Metal Concentrations in Fluctuation Zone of Three Gorges Reservoir Area Mo Fuxiao et al. （School of River and Ocean Engineering，Chongqing Jiaotong University，Chongqing 400074，China） Abstract：This study was devoted to fluctuation zone of Three Gorges reservoir area in Yunyang and the concentrations of Cu，Zn，Pb，Cd and Cr were determined which ranged from 175m to 163m in water-level-fluctuating zone soils. The result indicated that the total concentrations of Cu，Zn，Pb，Cd and Cr were 58.09mg/kg，108.93mg/kg，15.18mg/kg，0.46mg/kg and 71.81mg/kg，respectively. The profile distribution characteristics of heavy metal content changed regularly：the content of Cu，Cr and Zn in surface soil is higher than that of in the deep soil，but the content of Cr and Zn in surface soil is lower than that of in the deep soil at the dry-wet alternation；Content characteristics of Pb and Cd was the same，emerged as the surface is less than deep and the surface is more than deep at the dry-wet alternation. The study area was contaminated by Cd，Cu，Zn and Cr in varying degrees，but far from the Pb pollution；however pollution of Cd was particularly serious，even beyond the background value more than three times. Key words：Three Gorges reservoir area；Fluctuation zone；Heavy metal in soil；Characteristic；Pollution assessment 消落带是因水库调度引起的水位涨落而于库区周围形成的一段特殊区域。在人工调控下，三峡库区水位的周期性涨落会在两岸形成垂直落差30m、面积约348.9km2的消落带。消落带是水生生态系统与陆生生态系统的过渡地段，其土壤理化性质及重金属含量严重影响库区水质和周围动植物的生命活动。消落带土壤重金属污染具有隐蔽性强、形态多变、无法被生物降解、容易在生物体