关键词: 城镇体系, 空间组织, 绿洲, 酒泉地区

Abstract: Oasis is a pecular type of territory. The urban systems in oasis areas have their distinctive territorial characteristics because of their spatial limitation and environment capacity. As Ji-uquan Prefecture is concerned, its urban system boasts the fundamental features of its own: (1) great difference in spatial density organization; (2) "block-axis"distribution of spatial net-work; (3) weak spatial interaction. Therefore, the structure of the urban system must be ac-cordant with the oasis environment to make sure that the water resources can support the majorcities for further development. Around the three central cities (Jiuquan city, Yumen city andDunhuang city), the spatial structures of urban system in Jiuquan district are suggested as twopossible schemes, i. e. dual-core (Jiuquan city and Dunhuang city) and tri-core (Jiuquan city, Yumen city and Dunhuang city) ones. In the former scheme, Dunhuang city acts as, a core inwest part of Jiuquan district, and Yuanquan town and Iiuyuan town are looked as nodes, StateHighway 312, 215 and 313 boast the function of connecting belts in western part. In the area, tourism is taken as the doninant industry, with resource development and manufacture as prin-cipal part, agriculture and stockbreeding developing with the harmony relationship. In east partof the concerned region, Jiuquan city is looked as another core, and Yumen city and Jiayuguancity act as auxiliary settlements, to accelerate the industrialization and the urbanization, andrender the urban system become more perfect. In the latter scheme, Dunhuang city and Ji-uquan city are taken as different cores in western and eastern parts of the concerned region re-spectively, with Yumen city and Yumenzhen town as cores in the middle of the region. Though it is constrained by the shortage of water resource and the declining reserves inpetroleum, Yumen city is still boasts its largest population and the prominent centrality in theregion. Yumenzhen town, though smaller in size, will develop rapidly because it is the site ofthe Headquarter of integrated agricultural development for catchment of Shulehe river and theattracting center of the immigration of 200, 000 population, all of which will enhance develop-ing vigor in the middle of the region. As a conclusion, it is possible to set up tri-core spatialstructure of urban system, and offset the loose spatial structure with a much long span in spacein Jiuquan district.
Comparatively, the first scheme pays more attention to the historical development, andthe second one is more corresponding with the requirement of territorial exploitation and the de-velopment of urban system.

Key words: Urban system, Spatial organization, Oasis, Jiuquan district