干旱区生态环境知识资源中心

Desertification is a threat to human survival and has a major sustainability development impact on environment and socio-economic society. The study area where oasis desertification occurred is located east of the Ebinur Lake region, just west of Junggar Basin in Xinjiang, China. The ecological and environmental issues in the study area are vulnerable and sensitive. The authors of this paper discuss the changes in land desertification that occurred between 1990 and 2010. In the past 20 years, because of the human activities, such as population growth and agricultural development, desertification occurred rapidly in the study area. Remote sensing images were classified into eight categories: light desertification, moderate desertification, severe desertification, extremely severe desertification, bare rock, farmland, water body, and salt desert. To evaluate the evolution and status of land desertification as well as its causes, the authors interpreted and analyzed Landsat Thematic Mapper images (acquired in 1990, 2007, 2010) and Enhanced Landsat Thematic Mapper images (acquired in 2001) as well as meteorological and socioeconomic data. Results revealed that 4,426.49, 3,713.25, 3,713.95 and 3,789.16 km(2) of the total area is desertified land during these four periods (1990, 2001, 2007, and 2010). The factors controlling desertified land dynamics were analyzed from the perspectives of two groups: climatic variations and human activities. The results indicated that the climate-dominated natural factors contribute greatly to the occurrence and development desertified land. However, they are not the fundamental causes of its development. The human factors are the primary and direct driving forces responsible for the increase in desertification area. More thorough quantitative analysis, with more frequent remotely sensed data is needed to assess the driving forces in more detail.