Acta Geographica Sinica ›› 2006, Vol. 61 ›› Issue (9): 911-918.doi: 10.11821/xb200609002

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Classification and Assessment of Freeze-thaw Erosion in Tibet

ZHANG Jianguo1, LIU Shuzhen2, YANG Siquan3   

  1. 1. School of Geography, Nantong University, Nantong 226007, Jiangsu, China;
    2. Institute of Mountain Hazards and Environment, CAS, Chengdu 610041, China;
    3. National Disaster Reduction Center, MCA, Beijing 100053, China
  • Received:2006-05-18 Revised:2006-07-18 Online:2006-09-25 Published:2006-09-25
  • Supported by:

    Early-Stage Research on Key Basic Research Projects of China, No.2004CCA03600

Abstract:

Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Up to now, being restricted by many factors, few researches on freeze-thaw erosion have been done at home and abroad, especially on the assessment method of freeze-thaw erosion. Based on the comprehensive analysis of impact factors of free-thaw erosion, this paper chooses six indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze-thaw erosion using weighted and additive methods and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according to the relative classification result. The result shows that the distribution of freeze-thaw erosion area is very extensive, accounting for 55.3% of the total land area of Tibet. The spatial differentiation of freeze-thaw erosion with different intensities is obvious and the difference in distribution among different freeze-thaw areas is also obvious.

Key words: Tibet, freeze-thaw erosion, GIS, classification and assessment