Properties of Wetland Succession in Three Northeast Provinces Based on RS

Based on the MSS data in 1976, ETM data in 2001 and CBERS data in 2007, the wetlands data were obtained by the way of man-machine interactive interpretation and field checkout. The relative speed, displacement and transformation of wetlands were analyzed quantitatively in the three northeast provinces of China, aiming to provide a scientific basis for the protection and rational utilization of wetland resources in northeast China. The results showed that the existing wetland area of Heilongjiang, Jilin, Liaoning provinces was about 42 249.71 km2, 10 737.95 km2 and 9 744.79 km2 respectively. The wetland area decreased initially and then increased rapidly in the past 32 years. The largest range of variation and the largest relative speed of wetland area change were in Heilongjiang and Jilin Province respectively. The wetland barycenter was located in between Harbin city and Bin county, and moves continually towards the west. The transformation between wetland and non-wetland was obvious, most of which transformed into constructed wetlands, and the rate of transformation into marshese was high.