Nan Wei-Ge, Dong Zhi-Bao, Xue Liang, Zhang Zhi, Ha Yan-Qing, Shao Tian-Jie
School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China.
Huan Jing Ke Xue. 2024 Aug 8;45(8):4825-4836. doi: 10.13227/j.hjkx.202308168.
To clarify the impact of transportation on the sensitive and fragile ecosystems of the Qinghai Tibet Plateau and major ecological safety barrier functions, soil samples within 0-25 m on the roadside were collected from sections of national highways such as G214, G213, G345, G109, G316, and G317, and the contents of six heavy metals were analyzed. Then, the degree of heavy metal pollution and the risk of ecological hazards were evaluated using the single-factor pollution index method （）, Nemero comprehensive index method （）, and potential ecological risk index method （RI）. The results showed that the heavy metal contents of As, Cd, Hg, Ni, Pb, and Zn in the soil of important transportation national roads on the Qinghai Tibet Plateau ranged from 5.65 to 176.00, 0.04 to 0.27, 0.01 to 0.14, 9.52 to 113.00, 9.16 to 54.50, and 24.70 to 109.00 mg·kg, respectively, showing high variability. In some sections of the soil, the values of the elements As, Cd, and Hg were higher than the local soil background values. The single-factor pollution index of heavy metals in roadside soil was （As） > （Hg） > （Cd） > （Pb） > （Ni） > （Zn）. The Nemero comprehensive pollution index ranged from 0.41 to 9.20, with an average value of 1.53, indicating clean and mild pollution. Some areas showed a moderate or severe pollution. The average potential ecological risk index of the research section was 106.2, and the soil was generally in a state of no pollution and light pollution. Only two road sections had soil heavy metal enrichment reaching moderate and strong ecological hazards. The comprehensive potential risk of the G213a road section indicated moderate to severe ecological risk, mainly contributed by Hg, As, and Cd. The comprehensive pollution risk of the G317 road section indicated mild to moderate ecological risk, mainly contributed by Hg and Cd. The heavy metal content in the soil of the Qinghai Tibet Plateau road area was not significantly correlated with the roadside distance and soil depth but was significantly positively correlated with the annual average temperature （ 0.05）. In all, there was a trend of heavy metal input into the soil environment in areas with intense human activities and high traffic flow during road construction on the Qinghai Tibet Plateau.
为阐明交通对青藏高原敏感脆弱生态系统及主要生态安全屏障功能的影响，在G214、G213、G345、G109、G316和G317等国道沿线采集了路边0 - 25米范围内的土壤样本，并分析了六种重金属的含量。然后，采用单因子污染指数法（）、内梅罗综合指数法（）和潜在生态风险指数法（RI）对重金属污染程度和生态危害风险进行了评价。结果表明，青藏高原重要交通国道沿线土壤中As、Cd、Hg、Ni、Pb和Zn的重金属含量分别为5.65至176.00、0.04至0.27、0.01至0.14、9.52至113.00、9.16至54.50和24.70至109.00 mg·kg，变异性较大。在部分路段土壤中，As、Cd和Hg元素含量高于当地土壤背景值。路边土壤重金属单因子污染指数为（As）＞（Hg）＞（Cd）＞（Pb）＞（Ni）＞（Zn）。内梅罗综合污染指数范围为0.41至9.20，平均值为1.53，表明清洁和轻度污染。部分区域呈现中度或重度污染。研究路段的平均潜在生态风险指数为106.2，土壤总体处于无污染和轻度污染状态。仅两个路段土壤重金属富集达到中度和强生态危害。G213a路段的综合潜在风险表明为中度至重度生态风险，主要由Hg、As和Cd造成。G317路段的综合污染风险表明为轻度至中度生态风险，主要由Hg和Cd造成。青藏高原公路区域土壤中的重金属含量与路边距离和土壤深度无显著相关性，但与年平均气温显著正相关（ 0.05）。总体而言，青藏高原公路建设过程中，人类活动密集、交通流量大的区域存在土壤环境重金属输入的趋势。
