Acta Geographica Sinica ›› 2006, Vol. 61 ›› Issue (9): 957-964.doi: 10.11821/xb200609007

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Wind Tunnel Experiments on the Deflation Rates of Different Sediments in Arid Regions of China

LIU Lianyou1, SONG Yang1, LI Xiaoyan1, WANG Jianhua2, TUO Wanquan2, LIU Yuzhang2   

  1. 1. College of Resources Science and Technology; Key Laboratory of Environmental Change and Natural Disaster, the Ministry of Education of China, Beijing Normal University, Beijing 100875, China;
    2. Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China
  • Received:2006-01-19 Revised:2006-03-20 Online:2006-09-25 Published:2006-09-25
  • Supported by:

    National Natural Science Foundation of China, No.40471014; Ministry of Science & Technology, No.2005BA517A-11

Abstract:

By the wind tunnel experiment, we studied the deflation rates of 8 different sediments in arid regions of China, discussed the sources of aeolian sand and its influence on the development of sand dunes and formation of desert from the view of dynamics of wind erosion. Results of the study indicated that the average deflation rates of 8 typical sediments in arid regions of China can be arranged down: lacustrine sand > alluvial sand > weathered particles developed from sandshale > pluvial sediments > fluvioglacial sand > weathered particles developed from granite > slope deposit > glacial sediments. The deflation rates exhibited strong positive correlations with the erodible fraction—sand (0.063-2mm) content and sorting features. In contrast, the deflation rates have obvious negative correlations with the silt clay (< 0.063 mm) and gravel (> 2 mm) content. According to the deflation rates, the 8 typical sediments can be divided into four categories: (1) lacustrine sand and alluvial sand, which are prone to wind erosion, and are the main sources of aeolian sand; (2) weathered particles developed from sandshale, pluvial sediments and fluvioglacial sand, with the larger deflation rates, being the minor source of aeolian sand; (3) weathered particles developed from granite and slope deposit having the smaller deflation rates, only providing a small amount of aeolian sand; and (4) glacial sediments with a strong anti-erodibility, hardly offering any aeolian sand. Other than the strong wind conditions, the exposure of extensive lacustrine sand induced by the desiccation of inland lake basin, as well as the pre-sorting of sediments by flowing water are key factors in the development of deserts in China. It is the possible reason that deserts in China are mostly distributed along the inland lake basin and riverbank in a material light.

Key words: China, arid regions, sediments, wind tunnel experiment, deflation rate, sorting features