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Arid Land Geography ›› 2021, Vol. 44 ›› Issue (1): 168-177.doi: 10.12118/j.issn.1000–6060.2021.01.18

• Earth Surface Process • Previous Articles     Next Articles

Fractal spatial variability and its genesis of sediments in Suhongtu Gobi

LIU Xiya1,2(),WANG Haibing1,2(),ZUO Hejun1,2,XIAO Jianhua3   

  1. 1. College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010011, Inner Mongolia, China
    2. Key Laboratory of Aeolian Sand Control Engineering in Inner Mongolia, Hohhot 010011, Inner Mongolia, China
    3. Northwest Institute of Ecology and Environmental Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
  • Received:2019-06-28 Revised:2020-01-29 Online:2021-01-25 Published:2021-03-09
  • Contact: Haibing WANG E-mail:imaulxy@163.com;hbwang@imau.edu.cn

Abstract:

In the Gobi Desert, the composition structure of its sediments have fractal characteristics. These fractal characteristics and their variability to indicate sand’s role in the formation of surface sediments have not been well understood. In this study, we calculated the fractal dimension of surface sediments in the Suhongtu Gobi Desert, Alxa League, Inner Mongolia, China and analyzed its spatial variability. The results showed that the fractal dimensions of sediments increase with the increase of jumping components’ content (0.050-0.179 mm) and then decrease with the increase of creepping and wind erosion residual components’ content (0.179-20.919 mm). In the Gobi Desert, the wind is the dominant factor in shaping the landscape. Gobi sediments’ fractal values are smaller than those of alluvial and alluvial debris flow sediments (2.630-2.738) and larger than those of desert and loess sediments with dominant wind force (2.122 and 1.930, respectively). The wind force makes the Gobi Desert form a “homogeneous surface” with a spatial variability of moderate spatial correlation (32.8%). The dominant wind direction is exposed to the Gobi surface. The sediments are mainly composed of vermicular and wind erosion residual components (average content of 59.88%), and the mean fractal dimension is 2.39. When there is lower wind toward the semi-desert Gobi surface, the sediments are dominated by jump components (average content of 46.96%), with fractal dimension mean values of 2.45 and 2.48, respectively. Furthermore, with weak influence by the dominant wind, the sandy gravel surface between mountains has more vermicular and wind erosion residual components (average content of 58.22%), with a fractal dimension mean value of 2.46. Hence, fractal and variability indices can reflect the sand’s role in changing the Gobi sediments’ composition.

Key words: sediments, fractal dimension, spatial variability, Gobi