Dynamics Analysis of Desertification in Typical Farming-Pastoral Ecotone of Hobq Desert

This study area is located in the northeast of Hobq Desert,in farming-pastoral ecotone.The Land-sat TM images of 1987,1995 and 2003 were interpreted based on 3S software(ArcView 3.2,Erdas 8.6 and ArcGIS 9.0).This paper analyzed the desertification dynamics by comparing desertified area and degree of desertification in 1987,1995 and 2003.And the progresses of the land use change was analyzed by using convection matrixes from 1987 to 1995 and 1995 to 2003.The results show that: the area of desertified land decreased from 105 582.2 hm2 in 1987 to 83 326.7 hm2 in 2003.Meantime,changing trend of desertification degree decreased from 0.407 to 0.259 during this period.Desertified land mainly transferred to cropland,meadow and woodland.The main drive force of desertification change was agricultural activities.