Study On Land Use/land Cover Change And Ecologic Effects In Keriya Oasis

Land use and land cover change (LUCC) is the most significant aspect in the research field of globe changing. Research area—Keriya oasis,which located in southern Xinjiang,is one of the typical ectone on the margin of the Ta-kelamagan desert in Xinjiang and has the bad natural conditions。To make it the study area will be useful to protect and develop the eco-system in the western China。To study the area can help the local government take some effective measurements and work out the detailed plan。All those will make the local people rich as early as possible。So, in arid and semi-arid ecological environment the Keriya oasis was selected as a case. The LUCC and its ecologic effects for regional scale, which is a hot issue in current research area of resources and ecological environment, were studied in this thesis. The result shows below:1. The ratio of Area of head four land cover styles which are desert, water, low density grass and farmland to initial area of respective land cover is 91.41%, 78.27%,71.45%, 67.07% in sequent in Keriya oasis from 1989 to 1999. The ratio of low density grass, middle density grass and saltern to initial area of respective land cover is 58.21%, 35.56%, 31.52%. The self-stability of those land cover styles is bad. During this time, the biggest transferred area to other land styles and ratio is farmland. Its transferred area and ratio are 11.47% and 42km2. Mostly farmland had transferred to low density grass and high density grass. Other land cover styles mainly transfer to high density grass. Its area is biggest. Middle density grass and farmland are main land cover styles which transfer to high density grass, and the total area is 120.9km2.2.During 1999 to 2002, ratio of desert area to initial area is 91.67%, in Keriya oasis. Ratio of farmland area to initial area is 80.75%. The transferred area is 216.6km2. Unchanged ratio of low density grass, middle density grass and high density grass is 59.11%, 48.57% and 22.50%. Unchanged ratio of saltern is lowest, only 22.65% is unchanged. The ratio of low density grass, middle density grass and high density grass transfer to saltern reach to 47.74%, they are biggest. Especially middle density grass and farmland transferred area is respectively 26.5km2 and 17.8km2. Low density grass transferred area is biggest in all land cover types, the area is 114.5km2. They mainly transfer to middle density grass and desert. The ratio of high density grass transfer to other land is biggest, reach to 18.31%, they are mainly muster in...