向海湿地河道上下游土壤重金属污染程度分析

以向海湿地河道上、下游土壤沉积物为研究对象，以Al元素作为标准化元素，通过对重金属元素富集因子的分析，研究了Cu、Ni、Mn、Fe、Ba、Cr等6种重金属元素的人为污染状况及分级。结果表明，该区土壤沉积物中重金属元素均受到不同程度的人为污染影响，部分层面Ni、Ba等重金属元素污染程度达到显著水平，造成这种现象的主要原因是富含重金属的霍林河上游矿源物质的沉积及人类对湿地开发活动的历史变迁过程；此外，径流淹没频率不同造成了两断面土壤沉积类型和沉积效果的不同，使得受水文影响较大的上游断面的人为污染程度大于受影响较小的下游断面，说明向海湿地对人为污染具有一定的缓冲能力，或向海湿地具有较强的净化和过滤功能。

The pollution degree of heavy metals in the soils sampled along the river upstream and downstream in Xianghai wetland

The enrichment factors of 6 kinds of heavy metals (Cu, Ni, Mn, Fe, Ba, and Cr) were analyzed in the soils collected along the bank upstream and downstream in Xianghai wetland in China by using Al as normalization factor, and the classes of anthropo- genic contamination were investigated. The results indicated that the heavy metals were all affected by anthropogenic contamination in the soil samples, in particular, Ni and Ba reaching a significant level, which might result from coal mining sequences and the his- torical program of human utilization of the wetland. Furthermore, the differences of the runoff submerging frequency induced the differences of the sedimentation type and sedimentation effect between the two sections, and the pollution degree of the upstream which was obviously affected by hydrology, was greater than that of the downstream, indicating that there is some buffer, purifying or filtering function in the Xianghai wetland for the anthropogenic contamination.