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Chinese Agricultural Science Bulletin ›› 2025, Vol. 41 ›› Issue (29): 38-45.doi: 10.11924/j.issn.1000-6850.casb2025-0210

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Study on Stability and Fractal Characteristics of Soil Aggregates in Mine Spoil Areas

GUO Yiwei1(), ZHANG Yongying2, GAO Zihang3, FAN Chunmei3()   

  1. 1 Yunnan Central Water Diversion Project Construction Administration, Kunming 650051
    2 Yunnan Water Conservancy and Hydropower Survey, Design and Research Institute Co., Ltd., Kunming 650201
    3 College of Water Conservancy, Yunnan Agricultural University, Kunming 650201
  • Received:2025-03-10 Revised:2025-09-10 Online:2025-10-22 Published:2025-10-22

Abstract:

The condition of soil aggregates within mining-disturbed areas critically determines the selection and design of ecological restoration strategies for mined ecosystems. This study focused on open-pit mining-disturbed sites in eastern Yunnan. Specifically, representative soil samples were systematically collected from five typical mining-disturbed sites and one undisturbed control site at Dushi Mountain Mine, to characterize the stability of soil aggregates and their fractal dimension properties in mining-impacted environments. The results showed that mining operations significantly altered the distribution of mechanical soil aggregates and water-stable aggregates, further influencing key soil aggregate parameters including mean weight diameter (MWD), geometric mean diameter (GMD), and the proportion of aggregates exceeding 0.25 mm in diameter (R>0.25). These changes led to reduced soil structural stability, evidenced by the percentage of aggregate destruction (PAD) in both surface and subsurface layers of the mining-disturbed sites, which were 1.88-28.66 percentage points higher than control (CK) plots. Conversely, the water-stable aggregate stability rate (WASR) in mining areas was consistently lower than that of CK. Notably, under both dry and wet sieve methodologies, the fractal dimension of soil aggregates decreased significantly with increasing content of aggregates >0.25 mm. Therefore, the fractal dimension could be reduced and soil structural stability enhanced by increasing the content of soil aggregates larger than 0.25 mm. This study elucidated the stability and fractal characteristics of soil aggregates in mining-disturbed sites, providing a scientific basis for the selection and configuration of ecological restoration measures in post-mining ecosystems.

Key words: spoil areas, soil aggregates, stability, fractal dimension