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Arid Land Geography ›› 2023, Vol. 46 ›› Issue (11): 1868-1878.doi: 10.12118/j.issn.1000-6060.2023.061

• Biology and Pedology • Previous Articles     Next Articles

Accumulation characteristics and ecological risks of heavy metals in green land soils in core urban area of Urumqi City

LIANG Liang1(),GUO Xiaosong1,CHEN Hanjie1,XU Haofan1,ZHOU Yanbo1,XIE Shaowen1,2,3(),YANG Fen4,WEI Chaoyang4   

  1. 1. School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, Guangdong, China
    2. Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, China
    3. National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China/Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management/Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, Guangzhou 510650, Guangdong, China
    4. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2023-02-15 Revised:2023-07-21 Online:2023-11-25 Published:2023-12-05

Abstract:

Owing to rapid urban expansion and industrialization in China, the core urban areas of large cities have suffered from varying degrees of heavy metal pollution in the soil. Herein, the accumulation characteristics and ecological risks of six heavy metals (Cd, Cr, Cu, Pb, Zn, and Ni) in the soils of two distinct urban land types (urban park and transportation hub green lands) within the core urban areas of Urumqi City were systematically studied. The study yielded multiple key results: (1) Soil heavy metal concentrations in the green land soils of transportation hubs were higher than urban parks. Compared with the soil background values of heavy metals in Urumqi City, urban park green land of the core urban area exhibited light pollution, while the green land in transportation hubs demonstrated moderate pollution. (2) The comprehensive pollution index for soil heavy metals within urban park green land varied among different administrative regions, with Toutunhe District (2.85) showing the highest level, followed by Shuimogou District (2.13), Tianshan District (1.91), Xinshi District (1.85), and Midong District (1.23). Conversely, for green land in transportation hubs, the comprehensive pollution index of soil heavy metals differed across administrative regions, with Midong District (4.17) being the most heavily affected, followed by Sayibak District (3.24), Xinshi District (2.84), Shuimogou District (2.70), Tuotunhe District (2.50), and Tianshan District (2.37). (3) Regarding the potential ecological risk index for heavy metals in green soil of urban parks, the rankings among different administrative regions were as follows: Shuimogou District (101.68) >Toutunhe District (98.83) >Xinshi District (88.56) >Tianshan District (73.43) >Midong District (58.24). In addition, for transportation hubs green land, the potential ecological risk index of heavy metals for each administrative region exhibited regional disparities, with Midong District (177.60) being the most adversely affected, followed by Shuimogou District (131.75), Sayibak District (120.25), Xinshi District (105.76), Toutunhe District (105.63), and Tianshan District (82.12). The largest comprehensive pollution index and potential ecological risk index for urban park green land were observed in the Toutunhe and Shuimogou Districts, respectively, while the largest values for urban transportation hubs green land were documented in Midong District. (4) Spatial distribution characteristics revealed that high-value urban park green land was generally distributed in the central urban area, resembling islands of green amidst the urban landscape. Conversely, high-value heavy metal pollution of green land in transportation hubs was distributed in an island shape in the southwestern region of Midong District and the eastern part of Sayibak District, except for Ni. This study identifies key factors affecting the varying degrees of soil heavy metal pollution in different administrative regions, including the concentration of industrial enterprises, dense transportation arteries, and high population density. This study potentially provides a scientific basis and reference for the protection of the soil ecological environment in the core urban area.

Key words: soil heavy metals, urban park, transportation hub, environmental risk, Urumqi City