Variations in Fractional Vegetation Coverage over Eastern China during 1982-2006

This study calculated the fractional vegetation coverage (FVC) using NOAA AVHRR-NDVI data and the dimidiate pixel model and analyzed the mean FVC spatial pattern and the trends in variations in the FVC across eastern China (east of 105°E) during 1982-2006. The results show: (1) The mean spatial variations in the study area have a range of 0-84.2% and exhibit a pattern featuring high FVC in the south and low FVC in the north; the south-north gradient was higher in winter than in summer; (2) forest, shrub, crops, and grassland have annual mean FVCs of 49.9%, 44.7%, 40.4%, and 31.1%, respectively; among the types of natural vegetation, forest exhibits the largest seasonal differences (as high as 31.5%), shrub has intermediate seasonal differences of about 27.7%, and grasslands have the smallest seasonal differences (about 15.3%); (3) during 1982-2006, more than 74% of the study area exhibited an increasing trend in the Yellow River-Huaihe River-Haihe River (YHH) reaches, in the Guanzhong (GZ) area, and on the Northeast China Plain (NECP). The FVC increases in the YHH and GZ areas occurred mainly in the spring and winter, whereas those in the NECP occurred mainly in summer and autumn. The Yangtze River Delta and Pearl River Delta exhibited significant decreasing trends. These findings are expected to be valuable for investigating land-atmosphere interaction in eastern China.