Abstract: In the south of Traim Basin, there are a string of oases with beaded distribution, which are the central space of local socio-economic development for thousands of years. However, the arid climate and frequent blown-sand events made the south of Tarim Basin to be a typical area of extreme drought and ecological fragile zone. Since the implement of development strategy in West China, this area vigorously developed the featured horticulture. The continual land development activity made land use/land cover change significantly. Based on RS and GIS technologies, this paper selected four periods(2000, 2005, 2011 and 2013)remote sensing images of Landsat TM/ETM+/OLI data, and used manual visual interpretation to extract boundary of artificial oasis. The paper selected MODIS13Q1 data and adopted NDVI methods to extract boundary of natural oasis and oasis-desert ecotone, then used the spatial analysis function of ArcGIS10.0 to get the transfer matrix of land use types to investigate the characteristics of artificial oasis expansion. It turned out that artificial oasis in the south of Traim Basin showed a continuous increase trend. But the structure of changing source was different at each period:the proportion of natural oasis was decreased, the proportion of oasis-desert ecotone was rose steadily, and the proportion of desert was increased rapidly. To artificial oasis of different watersheds, it showed significant periodical and regional differences. And its structure of amplification source was owing to the relative location of its expansion. The growth of population and policy factors were the main reason why artificial oasis expansion increased and showed characteristics of periodical and regional differences. The degradation of natural oasis and oasis-desert ecotone may induce the retrogression of ecological barrier function, and then threatened security and sustainable development of the oases. Scientific and reasonable management of land use of regional oasis is the common responsibility and important task for research workers and local managers to maintain ecological system security and sustainable socio-economic development of oases in the south Traim Basin.

Key words: the south of Traim Basin, artificial oasis expansion, land use transformation