Journal of Geographical Sciences ›› 2006, Vol. 16 ›› Issue (4): 495-501.doi: 10.1007/s11442-006-0414-6

• Climate and Environmental Change • Previous Articles     Next Articles

Deflation rates of different clastic sediments in the arid regions of China

SONG Yang1, LIU Lianyou1, 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:2006-02-15 Revised:2006-04-20 Online:2006-12-25 Published:2006-12-25
  • Supported by:

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

Abstract:

By wind tunnel experiment, we studied the deflation rates of 8 different clastic sediments in the arid regions of China, discussed the sources of aeolian sand and their influence on the development of sand dunes and formation of sand deserts from the view of dynamics of wind erosion. The average deflation rates of 8 typical clastic sediments in the arid regions of China can be arranged in the order of lacustrine sand > alluvial sand > weathered sandstone and shale > pluvial sediments > fluvioglacial sand > weathered granite > slope deposit > glacial sediments. The deflation rates exhibited strong positive correlations with the erodible particle (0.063–2mm) content and sorting features. In contrast, the deflation rates had obvious negative correlations with the contents of silt clay (<0.063 mm) and gravel (>2 mm). According to the deflation rates, the 8 typical clastic sediments can be divided into four categories: (1) lacustrine and alluvial sand, which are readily prone to wind erosion, assumed to be the main source of aeolian sand; (2) weathered sandstone and shale, pluvial sediments and fluvioglacial sand with considerable deflation rates, might be the secondary source of aeolian sand; (3) weathered granite and slope deposit having the lower deflation rates, could supply a little aeolian sand; and (4) glacial sediments with a strong anti-erodibility, could hardly offer any aeolian sand. In addition to 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 clastic sediments by flowing water should be the key factors influencing the development of sand deserts in China. The possible reason the sand deserts in China being mostly distributed around the inland lake basins and along riverbanks could be better understood through sand source analysis.

Key words: sand source, sand deserts, wind tunnel experiment, deflation rate, sorting features