开放基金成果——SALINITY ANALYSIS OF DESERT WETLAND SOILS IN EXTREMELY ARID REGIONS

SALINITY ANALYSIS OF DESERT WETLAND SOILS IN EXTREMELY ARID REGIONS

Qianqian Gou^1,*, Guohua Wang¹, Jianjun Qu^2,3

1．College of Geographical Sciences, Shanxi Normal University, Linfen 041000, China;

2．Key Laboratory of Desert and Desertification, Chinese Academy of Sciences, Lanzhou, 730000, China

3．Dunhuang Gobi and Ecology and Environment Research Station, Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences, Dunhuang 736200, China

ABSTRACT

The Xihu desert wetland of Dunhuang (Gansu province) has the dual features of an extremely arid desert ecosystem and wetland ecosystem and plays a particularly important role in China. However, research on soil salinity in this region is very rare. This study collected samples of different soil types in the Xihu desert wetland ecosystem and analyzed the soil salinity characteristics at different sites.

This study provides theoretical and data support for the assessment of soil salinization, ecological restoration and sustainable use of desert wetlands. According to the results, of the eight types of ions in the Xihu desert wetland soils, Na⁺, Ca²⁺, Mg²⁺ and K⁺ dominate the positive ions, while SO₄^2-, Cl^- andHCO₃^- dominate the negative ions, but CO₃^2- was not detected. Na⁺ had the highest positive ion concentration, while K⁺ had the lowest concentration. Na⁺ was mainly present in the form of sodium andcalcium salts. SO₄^2- had the highest negative ion concentration, while HCO₃^2- had the lowest concentration. The salinity is mainly contributed by Na₂SO₄ and CaSO₄. The correlation analysis of the salt ions in the Xihu desert wetland soils suggested that there were correlations between the different salt ions in the soil and these reflected the sedimentation characteristics of the salts. The cluster analysis of soil salt ions showed that salinity analysis could be restricted to just three ions (Ca²⁺, Cl^-, and SO₄^2-) and these ions would sufficiently reflect the changes in the various salt contents in the Xihu desert wetland. The formation of saline soil in the research area was due to the combined actions of parent material, landform and hydrogeology.

KEYWORDS:

Extremely arid region; desert wetland; salt ions; salinization;characteristic analysis

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