地理研究

GEOGRAPHICAL RESEARCH ›› 2011, Vol. 30 ›› Issue (7): 1178-1186.doi: 10.11821/yj2011070003

• Earth Surface Processes • Previous Articles     Next Articles

Spatial variation of physical and chemical properties for eolian sand soil at longitudinal dune scale in southern Gurbantunggut Desert

QIAN Yi-bing1, WU Zhao-ning2, WANG Zhong-chen1,3, JIANG Chao1,3, YANG Hai-feng1,3   

  1. 1. Xinjiang Institute of Ecology and Geography, CAS, Urumqi 830011, China;
    2. College of Geology and Exploration Engineering, Xinjiang University, Urumqi 830046, China;
    3. Graduate University of Chinese Academy of Sciences, Beijing 100039, China
  • Received:2010-09-29 Revised:2011-01-18 Online:2011-07-20 Published:2011-07-20

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Abstract: The spatial variation of physical and chemical properties for eolian sand soil at longitudinal dune scale in southern Gurbantunggut Desert was studied by means of geostatistical methods. In the study, 184 samples of eolian sand soil from the quadrats of 5 m×5 m were systemically collected over the dune crests, slopes and interdune areas of two longitudinal dunes in southern Gurbantunggut Desert and 100 quadrats of vegetation were measured. The physical and chemical properties of eolian sand soil, including soil grain-size parameters, pH, salts, water content, total N and organic matter were determined. The results show that under the impact of longitudinal dune landform characteristics, including elevation, slope aspect, slope angle and partial micro-terrain and vegetation pattern, the physical and chemical properties of eolian sand soil have the variance of weak to medium extent and the spatial autocorrelation of moderate to strong extent. The values of spatial correlated ranges are 21.3-74.8 m, which approximately correspond to a width of single longitudinal dune or a width of landform unit from interdune area to dune to interdune. Because these soil properties have a nest structure of different level systems, the fractal dimensions, D values at different scales were gained. The D values of soil grain-size parameters (φ1, Mz,σ), soil salts (EC) and soil nutrients (organic matter and total N) in a sampling interval of 0-40 m are larger, and the spatial variation is basically medium to high level. Under a sampling interval of 90-150 m, the D values were sharply reduced and the spatial variations were greatly increased. The curve of variation strength for soil water contents was in several segments and the D values were gradually decreased in turn. The mechanism of the close relationship of the spatial variations between soil total N and organic matter contents shows that the spatial variations of the soil physical and chemical properties, which are expressed by the fractal dimensions and not regularly preprocessed, well accord with the field facts.

Key words: Gurbantunggut Desert, longitudinal dune scale, physical-chemical properties of eolian sand soil, spatial variation, fractal dimension