Vegetation landscape change analysis based on remote sensing in northwest of Beijing

Vegetation coverage change to the northwest of Beijing, which is upper drift zone, has an important influence on Beijing´s atmosphere environment and climate, while series of problems were caused by land-use change in this area. Therefore, we selected typical temporal remote sensing images in 1987, 1997, and 2008, which can represent climate´s feature in that decades, to retrieve vegetation coverage of land and chose landscape indexes to analyze spatio-temporal change characteristics of vegetation landscape in northwest of Beijing. Our result indicated that the least vegetation areas and the highest discrete index value with major high fractional vegetation cover type is in 1980s, while the largest vegetation areas and the lowest discrete index value with major high and middle fractional vegetation cover type is in 1990s. Furthermore, comparably, vegetation area in 2000s is much less than in 1990s. Although discrete index fluctuates in different decades, absolute value varies only a small extent, which may indicated that high fractional vegetation cover type prevails in northwest of Beijing, or middle fractional vegetation cover type connects mostly, and vegetation coverage patches aggregate in high degree, which demonstrated local nature environment differ not too much and ecosystem is relative stable.