Abstract: Based on the TM in 1999, ETM in 2000, ASTER in 2004, and the background data of the lower reaches of Tarim River, the dynamic changes of vegetation coverage and land desertification before and after the implementation of Emergent Water Project were studied. The results showed that with the implementation of the Project, the areas with medium and higher vegetation coverage increased from 7 447.16 hm² and 17 146.80 hm² in 1999 to 9 129.16 hm² and 26 236.61 hm² in 2004, and those with lower and poor vegetation coverage decreased by 9 989.10 hm² and 782.71 hm², respectively. In 1990-2004, the total area of desertification decreased from 506 258.06 hm² to 498 043.93 hm², and the ecological environment in parts of the esertification area tended to be improved, indicating that the Emergent Water Project played an important role in improving the ecological environment in the lower reaches of Tarim River.

Key words: northern grassland, GIMMS NDVI, phenology, climate