A Remote Sensing Analysis of Wetlands Dynamic Changes and Mechanism in the Past 32 Years in Bosten Lake,Xinjiang

Based on remote sensing images of 1975(MSS),2000(ETM) and 2007(CBERS-2),this paper interpreted lake wetland,marsh wetland,river wetland and cultivated land of Bosten Lake at the scale of 1∶50000.Some conclusions have been reached:The areas of lake wetland,marsh wetland and river wetland have decreased gradually,while cultivated land has increased significantly in the past 32 years.During the period from 1975 to 2000,the areas of lake wetland and total wetlands increased by a small margin,and cultivated land increased by 454.52 km2,but marsh wetland and river wetland decreased by 23.71 km2 and 18.44 km2 respectively.The resources of wetlands were destroyed seriously from 2000 to 2007.During these 7 years,lake wetland,river wetland,marsh wetland and total wetlands decreased considerably whereas cultivated land increased by more than 526.55 km2.The deterioration velocities of marsh wetland and river wetland were 37.13 and 5.24 times higher than the velocities during 1975~2000.Natural factors and human activities were two important factors responsible for the serious degradation of wetlands.Wetland-agriculture and wetland-desertification constituted two processes of wetland degradation.