|
| 西藏一江两河流域中部地区土壤重金属生态风险评价 |
| Ecological risk assessment of soil heavy metals in the middle of the “One River and Two Tributaries” basin in Tibet |
| Received:August 19, 2019 |
| DOI：10.13254/j.jare.2019.0421 |
| 中文关键词: 土壤，重金属，来源分析，生态风险评价，一江两河 |
| 英文关键词: soil, heavy metals, sources analysis, ecological risk assessment, “One River and Two Tributaries” basin |
| 基金项目:中国科学院战略性先导科技专项（XDA20040301） |
| Author Name | Affiliation | E-mail | | WANG Wei-peng | School of Renewable Energy, North China Electric Power University, Beijing 102206, China
Key Laboratory of Water Cycle and Related Surface Process, Institute of Geographic Sciences and Natural Resources, Chinese Academy of Sciences, Beijing 100101, China | | | LU Hong-wei | Key Laboratory of Water Cycle and Related Surface Process, Institute of Geographic Sciences and Natural Resources, Chinese Academy of Sciences, Beijing 100101, China | luhw@igsnrr.ac.cn | | FENG San-san | School of Renewable Energy, North China Electric Power University, Beijing 102206, China | |
|
| Hits: 1651 |
| Download times: 1686 |
| 中文摘要: |
| 为了深入研究西藏一江两河流域中部地区土壤重金属的污染特征，以该地区农田土壤为研究重点，对41个点的四层土壤S1（0~10 cm）、S2（10~20 cm）、S3（20~30 cm）和S4（30~40 cm）进行采样，分析测定了Cd、Cr、Cu、Hg、Pb、Zn、Ni和Mn 8种重金属含量。运用多元统计法分析重金属来源，并采用地积累指数、富集因子及潜在生态风险指数等方法对土壤重金属进行生态风险评价。结果表明：研究区各土层中S1土层的Cd、Cr、Cu、Pb、Zn、Ni和Mn含量较高，均值分别为0.21、82.95、34.67、35.81、75.31、49.99 mg·kg-1和697.39 mg·kg-1，但四层土壤各元素平均含量均低于国家农用地土壤污染风险筛选值。土壤重金属含量随土层加深而降低，S4土层含量最低，整体呈低水平分布。来源分析表明：浅层（S1、S2、S3）土壤中Cd、Cu、Pb主要受人为活动影响，Cr、Ni、Zn、Mn主要受自然源控制；S4土层受人为影响较小，重金属元素主要是自然来源。生态风险分析表明：S1土层中Cd的地积累指数、富集因子与单项生态风险参数相较于其他元素均处于较高水平，均值分别为0.790、1.973和77.782，有较明显的污染且属中度生态风险水平，其他土层的各元素参数均低于S1，呈轻微污染或无污染且属轻微生态风险水平。4个土层综合潜在生态风险指数均值最大为103.959，土壤整体处于轻微生态风险水平。研究表明，研究区土壤环境质量整体较好，Cd与Pb累积较重，值得关注。 |
| 英文摘要: |
| This study focused on the characteristics of soil heavy metal pollution in the middle area of the "One River and Two Tributaries" basin in Tibet. Four layers of soil, namely S1(0~10 cm), S2(10~20 cm), S3(20~30 cm), and S4(30~40 cm), at 41 points in the farmland soil were sampled; then, the concentrations of Cd, Cr, Cu, Hg, Pb, Zn, Ni, and Mn were determined. The sources of heavy metals were analyzed using the multivariate statistical method, and the soil heavy metal ecological risk was evaluated based on the geo-accumulation index, enrichment factor, and potential ecological risk index. The results showed that the concentrations of Cd, Cr, Cu, Pb, Zn, Ni, and Mn in soil layer S1 were higher, with mean values of 0.21, 82.95, 34.67, 35.81, 75.31, 49.99 mg·kg-1, and 697.39 mg·kg-1, respectively. The average concentration of each element in all four layers was lower than the risk screening values of soil contamination in farmland. The concentration of soil heavy metals decreased as the soil layer increased. Thus, the lowest concentration was observed in layer S4. Source analysis showed that Cd, Cu, and Pb in the surface(S1, S2, and S3)soil were mainly affected by human activities, while Cr, Ni, Zn, and Mn were mainly controlled by natural sources. Layer S4 was less affected by human activities, and the sources of its heavy metal elements were mainly natural. The ecological risk analysis showed that the geo-accumulation index, enrichment factor, and single ecological risk parameter of Cd in soil layer S1 were higher than those of the other elements with mean values of 0.790, 1.973, and 77.782, respectively. This indicated that layer S1 had significant contamination and a moderate ecological risk level. All the parameters of each element in the other soil layers were lower than those in layer S1, thereby implying that slight contamination and lower ecological risk. The average value of the comprehensive potential ecological risk index of the four soil layers was 103.959, thereby indicating that the soil in the study area was characterized by slight ecological risk. Generally, the quality of the soil in the study area was good, but the concentrations of Cd and Pb showed serious accumulation. |
| HTML
View Full Text
View/Add Comment Download reader |
| Close |
|
|
|
