Land Use/Cover Change of Urumqi Metropolitan Area based on Different Spatial Scales
基于不同空间尺度的乌鲁木齐都市圈土地利用/覆被变化研究

The Urumqi metropolitan area is located at the northern foot of the Tianshan Mountains in Xinjiang, China. It is an urban oasis in an arid environment. Economic growth in Urumqi is causing changes in spatial patterns, therefore it is necessary to study these changes based on land use/cover change in order to guide the sustainable development of the metropolitan area.We studied the land use/cover change patterns in Urumqi at multiple scales of analysis, based on remote sensing images and land use maps. The macro-scale analysis provides information on the arid regional context of Urumqi, the meso-scale explains the characteristics of land use change and spatial urban expansion trends, and the micro-scale analysis depicts the rules of urban land change and urban spatial patterns. From the macro-scale analysis of land use/cover change in Urumqi, we reached some conclusions on land cover characteristics and patterns of change. The land cover in mountainous areas, oasis and desert is very different. The actual land use change was indistinct, and the spatial patterns of land cover tend to be stable, but land use changed markedly in oasis areas, and land cover was strongly affected by changes in human activity. From the analysis of land use/cover change in oasis areas from 1989 to 2002, we see that agricultural land and built-up land expanded greatly and the spatial structure of the metropolitan area was formed. Bare land and natural vegetation decreased largely because of human activity, while agricultural land and land with buildings increased rapidly, and expanded in the northern part of the study area. For urban land change from 1998 to 2006, the area of the central city is much more than the others, so the city of Urumqi is dominant in the metropolitan area. The compact ratio of urban land generally increased but the central city is more dispersed than others, and the built-up land of each city expands in different amounts in different directions. The main land of the central city such as public areas, residential land and industrial land are regularly distributed. The medium and small cities do not have these characteristic because of their small size. Some industry clusters were planned in Changji and Miquan, so in these places there was an increase in industrial land area.