闽江下游土地利用格局对河流沉积物中重金属含量的影响

sediments of the Minjiang lower reaches

基于小流域划分方法对闽江下游河流沉积物中的重金属含量进行分析发现,闽江河口2条主要汇入支流表层沉积物中的Cr、Zn、Cu、Pb含量相对较高。对小流域土地利用格局与河流沉积物中的重金属含量的关系进行研究得出,Cr、Zn的含量受人类活动影响较大。城镇建设用地面积较高、城镇建设用地边界比较破碎的地区,Cr含量相对较高;而受人类活动干扰较小的林地,其Cr、Zn污染越低。可通过控制主要城镇地区点源、面源污染,调整小流域内林地种植面积、空间格局等,提高该地区的重金属污染防控水平。

Based on sub-watersheds,the heavy metal contents in sediments of the Minjiang lower reaches were sampled and studied.It was revealed that the contents of heavy metals in two branches nearby the Minjiang estuary were relatively high,especially Cr、Zn、Cu and Pb.Correlation analysis was performed to explore the relationships between the heavy metal contents and the land use landscape in Minjiang estuary.The results showed that the contents of Cr and Zn were positively correlated with human activities.The content of Cr was higher in urban areas where the construction areas were higher and land boundary was broken.The contents of Cr,Zn were lower in the forest areas.The efficiency of the heavy metal pollution prevention and control can be improved through controlling point and non-point source pollution in the main urban areas and adjusting the spatial pattern of land use in the watersheds.