Abstract:

Based on the Landsat5TM and disaster monitoring satellite CCD(HJ1A/1B)data during 2007~2009,the Vegetation Fractional Cover(Fc)in the drawdown area of the Three Gorges reservoir below 156 meter level was calculated by the dimidiate pixel model.This paper analyzed not only the spatial and temporal variation of the Fc in the drawdown area，but also the environmental impact factors.The Fc in 2007,2008,and 2009 was 512%、515%、492% respectively,and the Fc in stem stream area was higher than that in tributary.This was related with the geological conditions,and the slope determined the spatial difference of the Fc.The Fc of 2008 in the drawdown area was basically same with that in 2007,while the Fc in 2009 was lower than that in 2007 and 2008.This was related with the dynamic scheduling scheme of Three Gorge.When the water back later,the drawdown area exposed later,and the Fc was lower.The results show that the vegetation in the drawdown area of the Three Gorges basin has a certain ability to recover naturally.