城市地质2025，Vol.20Issue(2)：188-201,14.DOI:10.3969/j.issn.2097-3764.2025.02.007
2019-2023年北京市大气沉降重金属通量时空变化特征及源解析研究
Spatio-temporal variations characteristics and sources on heavy metals in atmospheric deposition of Beijing,2019-2023
摘要
Abstract
By testing atmospheric dry and wet deposition samples at 20 sites in Beijing from 2019 to 2023,we analyzed the changes in fluxes of heavy metals in atmospheric deposition at three key time points of 2012,2019,and 2023.The study further examined the spatiotemporal distribution,variation patterns,emission source characteristics,and source contribution rates of heavy metal deposition during the COVID-19 pandemic.The results show that in 2019,the atmospheric deposition fluxes of eight heavy metals,including As,Cd,Hg,Pb,Cr,Ni,Cu,and Zn,were 8.4%-42.3%of those in 2012.Among them,the flux of As decreased the most significantly.From 2019 to 2022,a continuous downward trend in fluxes was observed.The atmospheric deposition volumes at locations in districts such as Chaoyang,Shijingshan,Fangshan,and Daxing were significantly higher than those in other regions,primarily influenced by human emission activities.In mountainous areas with high geological background levels,such as Mentougou,Yanqing,Miyun,and Huairou,the fluxes of heavy metals in atmospheric deposition were more influenced by meteorological conditions such as rainfall.The enrichment levels of heavy metal in dry deposition followed the order:Cd>Zn>Pb>Cu>Hg>Cr ≈ Ni>As.Cd and Zn showed significantly higher enrichment levels than the other elements.The enrichment of Cd was significantly correlated with that of Hg and Ni,while Pb enrichment showed significant correlations with Cr,Ni,Cu,and Zn.Backward trajectory cluster analysis revealed that in the first quarter,northwesterly air masses originated from natural sources,traveled over longer distances,and were more conducive to the dispersion of atmospheric pollutants.Comparatively,during the second and third quarters,industrial cities in surrounding regions contributed to the input of polluting elements like As,Cd,Hg,Pb,and Zn into Beijing's atmosphere.The calculation results from the principal component analysis and APCS-MLR model indicated that among the atmospheric deposition elements,the weighted contribution rates of Pb,Zn,Cd,Ni,and Cu exceeded 13%,while Cr had the lowest contribution,accounting for only 3.06%.The elements such as Cu,Ni,Cd,Hg,and Pb in atmospheric deposition were primarily sourced from traffic emission sources(F1),with a contribution rate ranging from 57.63%to 76.22%;Cr and As were mainly derived from coal combustion sources(F2),with contribution rates ranging from 50.78%to 58.70%;Zn was primarily attributed to mixed sources(F3),including soil parent material dust and metallurgical dust,with a contribution rate of 69.64%.关键词
北京/大气沉降/重金属/时空变化/源解析Key words
Beijing/atmospheric deposition/heavy metals/spatio-temporal variations/source analysis引用本文复制引用
韩冰..2019-2023年北京市大气沉降重金属通量时空变化特征及源解析研究[J].城市地质,2025,20(2):188-201,14.基金项目
北京市政府公益性项目"北京市土地质量生态地球化学监测网运行"(11000022T00-0000439575)和"北京西部浅山区生态地质安全专项调查与评价"(11000023T000002075084)联合资助 （11000022T00-0000439575）
