农村-城市二元结构对典型山地河流沉积物重金属空间分布及来源影响研究

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中图分类号：X52 文献标志码：A 文章编号：1000-582X（2025）12-033-16

doi：10.11835/j.issn.1000-582X.2024.277

Abstract：The spatial distribution of heavy metals in the sediments of mountainous rivers is significantly influenced by population density and industrial structure.In December 2019，sediment samples were collected from the Taohuaxi River-a typical mountainous river spanning both urban and rural areas in Changshou District， Chongqing-to investigate heavy metal contamination.The concentrations of eight heavy metals were measured， revealing thattheir average contents intheurbansection were higher thanthosein theruralsection，with cadmium （Cd）and copper （Cu） showing significant differences. Population density was found to be a key factor shaping the spatial distribution of heavy metals in river sediments. According to the improved geoaccumulation index （Im） ， 20.59% of the monitored sites exhibited near moderate or moderate pollution，indicating localized enrichment of heavy metals along the river.Based on the potential ecological risk index （RI）， 67.65% of sites presented medium or high potential ecological risks.The sediment quality guidelines （SQGs） assessment further indicated that heavy metals posed a moderate toxicological risk toaquatic organisms.Overall，the ecological risk of heavy metals in the sediments of the Taohuaxi River should notbe overlooked.Positive matrix factorization （PMF）model analysis identified five major sources of heavy metals， with contributions in the order of aquaculture sources （38.79%）> natural sources （20.40%）> mixed anthropogenic sources （20.35%）> industrial sources type I （16.69%）> industrial sources type I （3.78% ）

Keywords： mountainous river; heavy metals; ecological risk; PMF model; source apportionment

人类活动会导致重金属元素在河流沉积物中累积，长期影响地表水环境。（剩余16889字）