A Fractal Study On The Structure Of Urban System In Gansu Province Based On Economic Regionalization

City is an open economic system, which not only exist with the surrounding regions of matter and energy exchange, but also the cities are constantly engaged in material, energy, information flow and exchange. Such spatial interactions between cities within the region to a certain level of different sizes, different functions of the nature of close links between cities, forming a certain structure and function of the organic whole of the city system. With the official launch of western development, western region's economy is facing a new round of rapid growth, especially for inland provinces like Gansu. If the city is the high degree set of economic and social development of industrialization, internationalization and modernization of the comprehensive sign, then the urban system can be said to be the skeleton of the regional economy and the very core of regional economic growth. It is of great significance in promoting regional economic growth and social development to study the dynamic mechanism of urban system structure and growth and formulate rational urban system developmentBased on the five economic zones in Gansu province (Longzhong, Hexi, Longdong, Longnan, Ganlin) as the basic research units, This paper uses fractal theory to analysis the urban system structure and status of Gansu province by calculating each economic region, city size distribution of sub-fractal dimension, obtained that Longdong?Ganlin?Hexi?Longnan?Longzhong. Longdong and Ganlin system are more concentrated in urban size distribution, small differences in urban scale, a more balanced population distribution, the middle rank larger number of towns; Longzhong, Hexi and Longnan have greatly differences in the distribution system of the urban population and the first city monopoly are high. Longdong and Longnan have fractal prominent system. Hexi and Ganlin system have fractal scale degradation, that is, the dual structure. Between the larger towns and smaller cities , it is lack of secondary towns, the scale of the transition is not natural.Through the space correlation dimension calculated, Longzhong city system in the spatial distribution mainly in roads, railways and other transportation lines, constitute the main traffic of cities in Gansu skeleton; Hexi town far away in space, spatial interaction is weak, not to the agglomeration effect, spatial structure of urban system development is imperfect; Longnan economic area distribution of various elements of urban system is relatively decentralized, there is obviously the first city. Longnan, Tianshui, the link in the economic space is more dependent on Sichuan and Shaanxi provinces, the space force between cities ate small, interrelated general level, the spatial structure of urban system is also less developed. Gannan, Linxia geographical distribution near the focus of regional cities and towns along the town providing the conditions for S-type beaded distribution, the basic form the point distribution system for urban axis. Eventually arriving at the present urban system characteristics: the first through is large; urban system is structural faults, poor communication; spatial structure of a small concentration, large dispersion; urban spatial interaction is weak, cities did not play to radiation; cities and towns under are natural conditions of the structure significantly.Finally the fractal analysis of the above results is summarized and proposed the development of rational urban system countermeasures and suggestions.