Spatial and temporal variation of the vegetation cover along Pearl River Basin based on SPOT 4-VGT
The characteristics of spatial-temporal distribution,fluctuation and trends of vegetation cover change a-long Pearl River Basin during 1998-2012 are analyzed based on sequential SPOT 4-VGT data.Standard deviation and linear regression techniques are used after the data are preprocessed.Results show:(1)From 1998 to 2012, the seasonal maximum NDVI change along Pearl River Basin is obvious.The peak appears in September and mini-mum in February,the average is 0.578,the mean maximum NDVI is on the rise during recent 15 years.The aver-age of maximum NDVI is 0.740.The vegetation cover condition is good,but there is an obvious spatial differ-ences.(2)The standard deviation of NDVI exists obvious space difference in Pearl River Basin.The three areas of bigger inter-annual fluctuations are the karst plateau of Pearl River source,the central basin of Guangxi Zhuang Autonomous karst region and the Pearl River delta region respectively.(3)In recent 15 years,the mean maximum NDVI trend shows that vegetation is overall improved,deterioration of parts.Improved area,degradation area and constant area account for 57.29%,9.20%and 33.5 1%of the total area respectively.
SPOT 4-VGTremote sensinsvegetation coverageremote sensingtrend analysisPearl River Basin