摘要
了解青藏高原河流沉积物重金属空间分布及来源,对揭示全球重金属元素地球化学过程具有重要意义.以雅鲁藏布江上游为研究对象,于2023年7月在雅鲁藏布江上游干支流采集了表层沉积物样品,分析了7种对环境及人体影响较大的重金属元素(Cr、Ni、Cu、Zn、As、Cd和Pb)含量和粒度组成.结果表明,研究区沉积物粒度组成整体以砂为主(57.3%),粗粉砂占比次之(23.2%),细粉砂(11.9%)和黏土(7.6%)占比较低;越靠近河源段沉积物砂占比越高;北岸支流砂占比大于南岸.与青藏高原土壤背景值相比,研究区沉积物Cr、Ni、As、Cd和Pb含量偏高;南北两岸支流沉积物重金属分布存在显著性差异,北岸支流Cr、Ni和As含量显著高于南岸,这种空间差异性与不同支流母岩岩石类型和不同强度的人类活动有关.根据PMF模型解析的结果,研究区南岸支流沉积物重金属自然因素来源贡献率为78.0%,人为因素来源贡献率为22.0%;北岸支流沉积物重金属自然因素来源贡献率为85.1%,人为因素来源贡献率为14.9%.研究可为理解自然因素和人类活动对雅江沉积物重金属地球化学过程的影响提供参考.
Understanding the spatial distribution and sources of heavy metals in river sediments on the Qinghai-Tibet Plateau is of great significance for revealing the global geochemical processes of heavy metals.Taking the upper reaches of the Yarlung Zangbo River as the research object,surface sediment samples were collected from the upper reaches of the Yarlung Zangbo River in July 2023,and the content and particle size composition of seven heavy metals(Cr,Ni,Cu,Zn,As,Cd,and Pb)that have great impact on the environment and human body were analyzed.The results showed that the grain size of the sediments in the study area was dominated by sand(57.3%),coarse silt(23.2%),fine silt(11.9%),and clay(7.6%).The sediment sand proportion was higher the closer to the river source.The proportion of sand in the north bank was larger than that in the south bank.The contents of Cr,Ni,As,Cd,and Pb in the sediments of the study area were higher than those of the soil background values of the Qinghai-Tibet Plateau.There were significant differences in the distribution of heavy metals in the sediments of tributaries on the north and south banks.The contents of Cr,Ni,and As in the north bank tributaries were significantly higher than those in the south bank.This spatial difference was related to the rock types of the parent rocks of different tributaries and the different intensities of human activities.According to the results of PMF model analysis,natural and human factors contributed for 78.0%and 22.0%,respectively,in the sediment of tributaries on the south bank of the study area.Natural sources and sources of heavy metals contributed for 85.1%and 14.9%,respectively,in the sediments of the north bank tributaries.This study can provide reference for understanding the geochemical processes of heavy metals in Yarlung Zangbo River sediments under factors and human activities.
作者
张咪咪
彭辉
刘佳
肖尚斌
ZHANG Mi-mi;PENG Hui;LIU Jia;XIAO Shang-bin(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China;Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,Yichang 443002,China;Postdoctoral Research Station of Hydraulic Engineering,Three Gorges University,Yichang 443002,China)
出处
《环境科学》
北大核心
2026年第3期1699-1708,共10页
Environmental Science
基金
湖北省自然科学基金创新发展联合基金项目(2022CFD032)
第二次青藏高原综合科学考察研究项目(2019QZKK0207)。
关键词
雅鲁藏布江上游
沉积物
粒度组成
重金属
来源解析
upper reaches of Yarlung Zangbo River
sediment
particle size composition
heavy metals
source analysis
