Analysis on Land Use/Cover Change and Landscape Fragmentation in Typical Watershed of Arid Zone in Last 30 Years—A Case of Manasi River Watershed,Xinjiang

This paper studied land use/cover change(LUCC) and landscape fragmentation in a watershed of arid zone—Manasi river watershed in last 30 years,by using GIS and FRAGSTATS with remote images in 1976,1989,and 2005.The results showed that the universal change of land use/cover has taken place in the watershed in last 30 years.Area of cropland and residence land increased continually,while grassland,forestland,water,saline-alkali land areas decreased.The significant spatial expansion in cropland agriculture led to rapid decrease of grassland.From 1976 to 2005,the distribution of cropland insides of Oasis was more centralized and the fragmentation became lower,but to the cropland near edge,its fragmentation increased.A large area of grassland was losing,became more fragmental and degenerate.The fragmentation of sand land and water area raised continually,in the same time,the fragmentation of forestland and bare land increased in 1989,then decreased in 2005.From analysis the driving factors,we found that rapid land use/cover change and landscape fragmentation occurred in the watershed were the results of fragile environment and strong human activity.Furthermore,the rapid population growth and government policies,and fluctuation of environmental factors such as drought might be the dominant macro-driving factors in the watershed.