青海湖典型湿地土壤重金属空间分布特征

以青海湖黑马河湿地为研究对象,对湿地土壤重金属铜、锌、铅、铬(Cu,Zn,Pb,Cr)4种元素的空间分布特征进行了研究。结果表明:湿地表层土壤(0—10cm)中,Cu,Cr,Pb和Zn的平均含量分别为16.38±4.95mg/kg,65.46±7.34mg/kg,14.26±4.28mg/kg,46.35±7.27mg/kg。垂直湖岸的水平方向上,Cu,Cr,Pb和Zn的含量高值出现在湿地高水位带以及陆相带,低值出现在湿地水陆过渡带。在土壤剖面方向上,各重金属元素表现出不同的分布特征:Cu呈现出表面聚集现象;Zn随深度变化有明显的淋溶和积聚趋势;Pb含量沿土层剖面纵深分布的特征是先增加后减少;Cr呈显著的表面聚集现象。湿地表层土壤的对比结果显示研究区内土壤环境质量良好。湿地土壤中Cu,Zn,Pb,Cr四种元素之间呈显著正相关,表明本区域重金属具有同源性。

Spatial Distribution Characteristics of Soil Heavy Metals of Wetlands in Some Representative Regions around Qinghai Lake

The content and distribution characteristics of soil heavy metals such as Cu,Zn,Pb,and Cr in wetlands of Heima River wetlands around Qinghai Lake were studied.The results showed that the average contents of Cu,Cr,Pb and Zn in top soil of 0—10 cm depth were 16.38± 4.95 mg/kg,65.46±7.34 mg/kg,14.26±4.28 mg/kg,46.35±7.27 mg/kg,respectively.In the horizontal direction to perpendicular the shore,the high contents of Cu,Cr,Pb and Zn appeared in the high water level and terrestrial area in wetlands,while low contents appeared in water and land transition zone.In the soil profile direction,different heavy metals showed different distribution.Cu presented a surface aggregation;distribution of Zn showed significant leaching and accumulation trends to soil profile;Pb increased first and then decreased along the soil profile;distribution of Cr showed a significant surface aggregation.Comparison among these elements showed the quality of soil in the study area maintained a good natural level.Cu,Zn,Pb and Cr exhibit a significant positive correlation with each other,which indicated that there was a homology among them in the study area.