Interannual variation of vegetation and precipitation in Pearl River Basin during 1982-1999

Based on the monthly normalized difference vegetation index(NDVI) and precipitation data in the Pearl River Ba-sin from 1982 to 1999,the relationship between NDVI and precipitation anomaly on the annual and interannual time scales are analyzed using empirical orthogonal function(EOF) method.Correlation coefficients between NDVI,precipitation,and other climatic factors are also analyzed.There is a good spatial coincidence between the variation of NDVI and that of precipitation anomaly in terms of annual variability,with NDVI lags one month.The interannual anomalies of NDVI and precipitation have obvious difference in their spatial distributions.Positive correlation is found in the west of the Pearl River Basin,while nega-tive correlation is found in the east.The relationships between NDVI and climate factors are different in different seasons and different domains.The correlation coefficient between NDVI and precipitation is negative in the east and positive in the west.The relationship between NDVI and temperature is positive in the east and not significant in the west;same for the relation-ship between NDVI and solar radiation.In summer,the NDVI and precipitation have negative relationship,which reverses in spring and fall.