关键词: 天山北坡城市群, 空间结构, 空间组织, 空间形态, 社会经济联系, 资源环境制约

Abstract: Oasis urban agglomerations have distinctive spatial organizations and morphology with other urban agglomerations as their special landforms and environmental restricts． So how to understand the particularity of oasis urban agglomeration development，and then put forward the suitable development suggestions is an important issue．This paper takes urban agglomeration on the north slope of the Tianshan Mountains as an example，aiming to identify the particular development mode of this representative arid urban agglomeration. Many statistical models and methods were used to interpret the spatial organizations. To be mentioned, visualization of urban agglomeration's spatial morphology was innovatively made in this paper. There are three steps to identify the spatial organization of the urban agglomerations. First, central cities in this region should be picked up. Here, centricity analysis method was used to identify central cities in this region. Indices such as GDP, population in each city, urbanization rate, employee in the third industry, and so on, were considered, and then entropy method was used to integrate these indices and got centricity of each city. Two cities,whose centricities were much higher than others, were chosen as central cities in this urban agglomeration． Second, spatial impact regions of each central city need to be divided. Method of Voronoi polygons revised by breaking point theory was used to divide spatial and economic affected areas of two central cities．The breaking point theory tried to find the dividing point between two central cities by considering population, industry, spatial distances, and so on. This dividing point can well represent cities' social and economic radiation threshold. Then, referenced the dividing point, Voronoi polygons were made to divide the spatial impact regions of each central city. Third，spatial organizations of this urban agglomerations should be visualized. Interaction model was used to identify social and economic interaction intensity among the cities. Accordingly, multidimension analysis was adopted to visualize spatial morphology of urban agglomerations based on the interaction intensity. From the visualization map, the urban agglomeration's spatial morphology was easily seen as beadsstrings. The agglomeration morphology has not been formed yet, but some urban groups. Considered the special land forms and its strict environmental restrictions, this paper suggests that the further development pattern should be compact along the main traffic roads. Accordingly, several conclusions were got as follows: (1) Two central cities exist in this agglomeration as the remote distances between cities, Urumuqi and Karamay．The urban agglomeration on the north slope of th Tianshan mountains has not formed yet，there are still several urban groups developed．(2) The interactions between cities，especially between two central cities，are still weak due to remote distances．(3) Spatial morphology of this urban agglomeration is beadsstrings，one special kind of corridor type，which may be representative for oasis urban agglomeration． Cities should take compact development mode to protect limited recourses and environment, and also information technology and modern traffic way should be adopted to shorten the distance between cities．

Key words: urban agglomeration in North Slope of Tianshan Mountain, spatial structure, spatial organization, spatial morphology, social and economic interaction, restriction of resources and environments