干旱区生态环境知识资源中心

Current study investigated the spatio-temporal distribution of fractional vegetation coverage (FVC) and climatic factors response in Three Gorges Reservoir area from 2000 to 2014 using a dimidiate pixel model. Several data sets were used including the MODIS NDVI data, land use/cover change (LUCC) data and past 15 years of FVC data. Our results suggested that, except 2006 the annual maximum FVC were stable from 2000 to 2014. Extremely arid climate in 2006 influences FVC of Three Gorges area. The annual average FVC of the study area was 91.28%. The monthly mean FVC showed a regular fluctuation, where mean higher FVC values were found from May to August and from December to March of the following years FVC was lower. Overall study area showed an upward trend of FVC from 2000 to 2014, basic invariant areas, slight increased areas and obvious increased areas were accounted for 84.70%, 8.75%, and 0.78% respectively, whereas significantly reduced areas and mild reduction areas were accounted for 1.52% and 4.25% FVC, respectively. The FVC growth areas were mainly distributed in the eastern part of the Three Gorges Reservoir area whereas degraded areas were mainly distributed in the hilly areas of the West and middle of the Three Gorges area. Greater than 2000 meters high mountains the FVC value reached 98.47%, and the slope greater than 25 the regional FVC value reached 92.60%. Strong correlations were observed between monthly mean temperature and FVC (R=0.88), precipitation and FVC (R=0.77), and growth season lag 1 month of FVC values and temperature (R=0.85).