干旱区生态环境知识资源中心

Along with the rapid development of urbanization since 1980s, immense changes of the land use/cover have been caused a series of problems of ecological environment, such as farmland decreasing, natural vegetation damage, construction land expansion, land desertification and salinization, and so on. The research on the changes and driving forces of spatial pattern of land use/cover by remote sensing is conducive to master the influences on ecosystem from natural factors and human factors and accelerate sustainable development of ecological environment. The LandSat MSS/TM/ETM+ images were used in the paper. Taken support vector machine (SVM) as classifier, the supervised classification was carried out to extract the spatial distribution of each land cover types in 1978, 1992, 2000 and 2010. By calculating the transition matrix among four result images, the changes of spatial patterns of land cover in Beijing in recent thirty years was analyzed from numeral and spatial dynamics. Result showed that the land use/cover in Beijing region had changed a great deal from 1978 to 2010. The farmland area and unused land area were decreasing with a range more than 40% in recent 32 years, while the urban area and forest area were increasing with a range more than 35%. Most of the farmland was transformed into urban land and forest, while the grassland was transformed into farmland. The input urban area was mainly originated from farmland, while the output was grassland. It indicated that the urbanization and afforestation were the two primary drivers of land use/cover change in Beijing region in recent thirty years.