Arid Zone Research ›› 2021, Vol. 38 ›› Issue (2): 402-410.doi: 10.13866/j.azr.2021.02.11

• Soil Resources • Previous Articles     Next Articles

Soil aggregates stability and fractal features on dump slopes of opencast coal mine in Funxin, China

WANG Kai1(),NA Enhang1,ZHANG Liang2,LIU Feng3   

  1. 1. College of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, Liaoning, China
    2. River Embankment Management Station of Longjing, Longjing 133400, Jilin, China
    3. CCTEG Shenyang Research Institute, Shenyang 110016, Liaoning, China
  • Received:2020-05-20 Revised:2020-07-11 Online:2021-03-15 Published:2021-04-25

Abstract:

There are serious soil and water loses on dump slopes of opencast coal mines. To provide a theoretical basis for ecological restoration on dump slope, the effects of slope aspect, slope position, and recovery time on soil aggregate stability and fractal features of opencast coal mine dumps in Funxin were explored. In this study, the differences of the mean mass diameter (MMD), geometric mean diameter (GMD), fractal dimension (D) and percentage of aggregate destruction (PAD) among the upper, middle, and lower parts, and between the sunny and shady slopes and their influence factors were analyzed on a five year and ten year recovery slope. Results showed that the MMD and GMD of soil aggregates gradually increased. In contrast, the D and PAD of soil aggregates gradually declined from the upper to the lower parts on a five year recovery shady slope and a five year and ten year recovery sunny slope. The MMD and GMD of soil aggregates on the shady slope were greater than on the sunny slope, and the D and PAD were lower on the shady slope than on the sunny slope. However, no significant differences were found in MMD, GMD, D, and PAD of soil aggregates between the five year and ten year recovery slope. Compared to the bare land, the soil aggregate stability decreased in the upper part but increased in the middle and lower parts. The D of soil aggregates was significantly negatively correlated with >0.25 mm soil aggregates, MMD and GMD were significantly positively correlated with D and PAD of soil aggregates. Moreover, there were significant negative correlations between the D of mechanically stable aggregates and the soil water content, and between the D of water-stable aggregates and organic matter content. These results demonstrated that the soil structure and stability were better on shady than sunny slopes and on lower than upper parts. Therefore, different artificial restoration measures should be conducted based on different slope aspects and positions.

Key words: mine dump, soil aggregate, slope aspect, slope position, mine ecological restoration