| 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. |
| 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 |
| 投稿时间：2024-11-11 |
| DOI：10.11654/jaes.2024-0973 |
| 中文关键词: 林周县 高海拔农业区 农用地 重金属 分布特征 风险评价 |
| 英文关键词: Linzhou County high-altitude agricultural areas agricultural land heavy metals distribution characteristics risk assessment |
| 基金项目:中国地质调查局项目（DD20243093） |
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| 中文摘要: |
| 为揭示特殊生境下高海拔农用地土壤重金属迁移累积的异质性规律，在林周县南部农用地采集403个土壤样品，测定As、Cd、Cr、Cu、Pb、Zn、Ni、Hg 8种重金属含量，基于地统计学分析揭示了土壤重金属的空间分布特征，采用单因子污染指数法、内梅罗综合污染指数法、地累积指数法以及潜在生态风险指数法对研究区土壤环境质量进行了综合评价，并结合相关性分析和主成分分析结果，对土壤重金属的主要来源进行了探究。结果显示：研究区土壤As、Cd、Cr、Cu、Hg、Ni、Pb、Zn含量的平均值分别为21.1、0.170、58.4、24.5、0.076、26.0、31.1 mg·kg-1和 79.2 mg·kg-1，均低于《土壤环境质量农用地土壤风险管控标准（试行）》（GB 15618—2018）中规定的筛选值。与其他高海拔地区（如青藏高原东部）相比，林周县土壤Cd和Hg富集程度较高，这可能与农业活动和交通污染密切相关；而Cr和Ni主要受成土母质影响，其空间分布模式与青藏高原其他区域类似。单因子指数评价结果表明，Cd和Hg的污染指数较高，部分采样点存在潜在生态风险。综合潜在生态风险指数平均值为107.42，呈现低生态风险水平，但个别点位存在中度至较重风险。As、Cd、Pb、Zn主要来源于交通污染源，Cr、Ni主要受成土母质控制，Hg主要受化石燃料和生物燃料集中燃烧的影响，Cu主要来源于交通污染源，同时受成土母质影响。 |
| 英文摘要: |
| 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. |
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