An Analysis of Spatio-temporal Changes and Spatial Heterogeneity of Vegetation Coverage in Pearl River Delta

Vegetation coverage Spatio-temporal changes in Pearl River Delta(PRD) were analyzed based on SPOT-VGT NDVI time series data for 10 years from 1999 to 2008,and the Moran's I index and semi-variogram function were calculated by using GIS and geostatistic method.Research results showed that the annual average NDVI increased by 9.2% with a fluctuation of up-down-up in the past 10 years,the vegetation coverage in the metropolitan interlocking region of PRD degenerated significantly disturbed by urbanization processes and man-made factors to a certain extent,while the NDVI in the outer portion increased significantly and these areas are becoming an ecological barrier of PRD.The spatial distribution pattern of NDVI shows negative autocorrelation on a global scale,but there were anisotropic structural difference and a higher positive spatial correlation in 135 °(NW-SE) direction.The NDVI spatial distribution was mainly controlled by structural factors,80.3%of the total spatial variation was influenced by structural and 19.7%by random factors.The study indicates that the impacts of Vegetation coverage changes on the eco-environment can not be neglected or ignored in the rapidly urbanizing area in China.