Abstract: The land use/cover changes(LUCC) plays an important role in ecosystem stability, human existence and sustainable development of society. It is important to comprehensively understand LUCC. On the one hand, it can help to understand the characteristics of regional environment and the change mechanism of ecological system, and further guide the controlling and planning for region environment. On the other hand, it is important for regional space guarantee in ecological system stability and sustainable development. The Urumqi River basin belongs to the semi-arid region in northwest China, and has fragile ecosystems. With the severe climate change and rapid urbanization, the environment problems that caused by LUCC in Urumqi River basin have aroused great concern from the government and the public. However, the study of LUCC in Urumqi River basin has been reported rarely in recent years, thus it is necessary to comprehensively research the LUCC in Urumqi River basin. Based on remote sensing image from Landsat series of satellite in 2006, 2010 and 2014, the data of land use/cover in the middle and upper reaches of Urumqi River were interpreted. The quality in different land use/cover types were characterized as the month average NDVI(Normalized Difference Vegetation Index) during growing season within the scope of its land use/cover type. Based on these data, the changes in spatial pattern and quality for land use/cover in the middle and upper regions of Urumqi River basin during 2006-2014 were analyzed. The results show as follows:(1) In recent 9 years, the area of forest was relative stable, while the area of grassland increased 12.78 km². Attributed to the intensive human intervention, the areas of construction land and farmland increased 5.01 km² and 3.84 km², respectively.(2) Although the NDVI in both forest and natural grassland did not change, a significant improvement was found in residential green. However, a slight degradation trend with a linear tendency of 1.5%·a^-1 was detected in the entire study area, which was more attributed to the decline of NDVI in farmland.(3) The disturbance of human activities was identified as the main driver that caused regional land use/cover change. Meanwhile, the destruction and protection worked at the same time in different part of vegetation, but the former effect was stronger than the latter. Specifically, the significantly improved and degraded area accounted for 5.92% and 9.45% of the total area, respectively.

Key words: the middle and upper reaches of Urumqi River, LUCC, the quality of land use/cover, NDVI