农业环境科学学报2025，Vol.44Issue(10)：2579-2589,11.DOI:10.11654/jaes.2024-0973
西藏林周县农用地土壤重金属分布及生态风险评价
Characteristics of heavy metals and ecological risk assessment in agricultural soils of Linzhou County,Tibet
摘要
Abstract
To investigate the heterogeneous mechanisms of heavy metal migration and accumulation in high-altitude agricultural soils under unique eco-environmental conditions,a total of 403 soil samples were collected from agricultural lands in southern Linzhou County.Eight heavy metals-arsenic(As),cadmium(Cd),chromium(Cr),copper(Cu),lead(Pb),zinc(Zn),nickel(Ni),and mercury(Hg)—were analyzed for their concentrations.Integrated with geostatistical analysis to characterize spatial distribution patterns,the environmental quality was comprehensively assessed using single factor index,Nemerow composite index,geo-accumulation index,and potential ecological risk index methodologies.Furthermore,combined application of correlation analysis and principal component analysis(PCA)was conducted to identify predominant contamination sources.The results revealed that the average concentrations of As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn were 21.1,0.170,58.4,24.5,0.076,26.0,31.1 mg·kg-1 and 79.2 mg·kg-1,respectively.All these values were below the screening values established by the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land(GB 15618-2018).When compared to other high-altitude regions,such as the eastern Tibetan Plateau,Linzhou County exhibited higher levels of Cd and Hg,likely due to agricultural practices and traffic-related pollution.In contrast,Cr and Ni concentrations were primarily controlled by the parent material,and their spatial distribution patterns resembled those observed in other regions of the Tibetan Plateau.Univariate index method evaluations indicated that Cd and Hg exhibited higher pollution indices,with certain sampling points showing potential ecological risks.The average Hakanson potential ecological risk index in the study area was 107.42,suggesting low ecological risk,though some points indicated moderate to high risks.As,Cd,Pb,and Zn are primarily derived from traffic sources.Cr and Ni are primarily controlled by background materials.Hg is primarily influenced by the concentrated combustion of fossil fuels and biofuels,whereas Cu is predominantly derived from transportation sources and is also influenced by the parent material of the soil.关键词
林周县/高海拔农业区/农用地/重金属/分布特征/风险评价Key words
Linzhou County/high-altitude agricultural areas/agricultural land/heavy metals/distribution characteristics/risk assessment分类
资源环境引用本文复制引用
张杰,袁新,冯俊波,刘坤,毛瑾,苏景..西藏林周县农用地土壤重金属分布及生态风险评价[J].农业环境科学学报,2025,44(10):2579-2589,11.基金项目
中国地质调查局项目(DD20243093)Project for China Geological Survey(DD20243093) （DD20243093）
