Analysis of Land Use/Cover Chang in Shiyang River Basin During the Period of 1998—2005

Based on the images in 1998 and 2005,the variations of quantity,inner structure,type,and spatial distribution feature of Shiyang River basin in seven years were analyzed by using RS and GIS and the driving forces of the land use/cover change(LUCC) were further discussed.Results indicated that during the seven years,the areas of grassland,Gobi,sandy land,woodland,dryland,and saline-alkaline land in Shiyang River basin were decreased and alpine,residential area and irrigable land were increased.The most significant increase is the irrigable land and its increased area is 89 485.22 hm2,which was mainly converted from woodland,saline-alkaline land,residential area,sandy land,and Gobi.The land use dynamic degrees of artificial woodland,saline-alkaline land,and irrigable land were 4.14%,3.48%,2.23% and 2.56%,respectively.The driving forces of the LUCC in Shiyang River basin were the economic development,the pressure of increasing population,and ecological policies.