RS-and-GIS-supported forecast of grassland degradation in southwest Songnen plain by Markov model

By taking Daan city in Jilin Province as a research object and by using TM image in 1989 and ETM⁺ image in 2001 from American LANDSAT satellite, all kinds of maps and documentation, information of grassland, saline-alkalize land, cropland, water area and forestland is extracted by man-computer interactive interpretation method with Arc View and ArcInfo GIS software, and statistics data is acquired. On the basis of this the changing trend of land use types in the next ten years is forecasted and analyzed with Markov model. The results indicate that the problem of grassland degradation in the study area is quite serious.