1. School of Geographic Science and Tourism, XinJiang Normal University, Urumqi 830054, China;
2. Center of Xinjiang urbanization development study, XinJiang Normal University, Urumqi 830054, China
Abstract Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north. It is also sometimes referred to as Middle Asia, and is within the scope of the wider Eurasian continent. For each of the cities, two co-registered Landsat images coincident with years 1990 and 2000 were required to characterize urban change. Since ideal months and years of image acquisition were not always available, some images deviated from the decadal time-points (1990 and 2000), or months of acquisition were offset by one month. In addition to the standardized spatial extent boundary, a core urban area was delineated for each city based on the density of urban land in 1990. Then the spatial-temporal changes in the five Central Asian countries' capital cities during the period from the beginning of 1990s to the beginning of 2000s were analyzed by computing the intensity of urban expansion, urban growth rates and compact ratios. The results showed that: in the period of 1990-2000, intensity of urban expansion and urban growth rates of in the five Central Asian countries' capital cities are much different from each other, intensity of urban expansion and urban growth rates of Ashgabat is the largest, respectively 0.93 and 4.6. But intensity of urban expansion and urban growth rates of Dushanbe is the smallest, respectively 0.001 and 2.6. However the compact ratios are not big changes. In 2000, the compact ratios in Dushanbe and in Tashkent are respectively 0.6 and 0.46. The urban spatial morphology of Ashgabat and Dushanbe are more compact, but the urban spatial morphology of Astana, Bishkek and Tashkent are less compact. All these five Central Asian cities are continuously expanded, but the direction and speed of urban expansion are different.
2012, Vol. 27 
