DECADAL CHANGES OF OASES IN THE KASHGAR REGION FROM 1975-2015

Oasis in arid and semiarid lands is vulnerable to climatic changes and human activities. Spatial analyses with remote sensing and GIS (geographical information system) technology provide very useful tools to monitor its long-term dynamic change. In this study, the spatio-temporal changes of the oases in the Kashgar region have been analyzed by integrating remote sensing data (5 periods of Landsat images of 1975, 1985. 1995, 2005. and 2015), socioeconomic data, meteorological data, and hydrological data. The results show that oases in the Kashgar region have gradually changed over the past 40 years. The artificial oases area increased from 10432 km2 in 1975 to 23334 km2 in 2015, while the natural oases area decreased from 17270 km' in 1975 to 5270 km2 in 2015. Although the increased precipitation and temperature would contribute expansion of natural oases owing to the vegetation growth, the increasing human-induced land reclamation, and water consumption may cause the large-scale expansion of artificial oases. During the period between 1975 and 2015, the cultivated land area increased by 5450 km2, meanwhile, the population increased from 2.05 million to 4.5 million. Therefore. the increase of artificial oases area from 1975 to 2015 probably arose due to the large-scale land reclamation, rapid population growth. and increasing water consumption. This study will enhance our understanding of the driving mechanism of the oases dynamic changes under the influence of human activities and climatic changes.