Analysis On Vegetation Cover Pattern Change In Beijing Based On 3S Technology

The changes of vegetation will directly cause landscape pattern's changes. It is very important for us to analyze the landscape pattern changes for evaluating ecology environment. In order to analyze the temporal and spatial process and features of vegetation changes in Beijing, and provide scientific basis for decision-making of environment construction,the study will take landscape ecology theory,landscape pattern analysis and 3S together in research work.Firstly, the study selected 3 years TM images in recent 10 years, calculated normalized difference vegetation index (NDVI) and drew the map of vegetation grades. Secondly, it established classification of landscape ecology basing on vegetation form and Land cover form, and classified the images by Decision Tree and finished Landscape type map. At last, we choose the landscape pattern as analyzing indicator, and it has been analyzed basing on landscape metrics and obtained correlation index by GIS.The result shows that there is a higher rate of landscape vegetation in West Mountain Land and North Mountain Land. The ecological environment is comparatively stable especially in West Mountain Land, but the rate of vegetation has decreased in these years in Beijing city. Various classes' mutual transformation happened in Southeast Plain Land. The result indicates that the ecological environment is unsteadiness and fragmentation in Southeast Plain Land.