Fractal Study on Urban Systems in the Underdeveloped Regions in West China A Case Study in the Lanzhou Xining Town Compact Region
Regional background of urban system growth is formed under the special natural, geo position and historical conditions,population,natural resources and economic development in different regions,which affects the growth process and development laws of urban systems.In this paper,the fractal theory is used to carry out a case study on the spatial structure,scale structure and formation mechanism of urban systems in the Lanzhou Xining town compact region,an underdeveloped region in west China.The characteristics of spatial structure and scale structure of the urban systems under the special natural,social and economic conditions in the underdeveloped region in west China are revealed by researching the fractal dimensions of the urban systems.The results show that the distribution of scale grades of the urban systems is dispersive,there is an obvious primate distribution,development of the large and mid sized cities is insufficient,scale grades of the urban systems are generally low,and the evenness of urban population distribution is poor;the spatial development degree of cities and towns is low,spatial distribution is quite uneven,decentralization is high,and the density of cities and towns away from the central cities is attenuated rapidly;the mature degree of spatial development of cities and towns is poor in some regions,and the spatial fractal characteristics are unconspicuous and even the fractal structure is not formed yet.Comparatively,the scale structure and spatial distribution of the urban systems in the relatively developed regions are characterized by evenness and network,the development of the primate cities has been in harmony with the development of urban systems,and the regional development is driven by the city town groups;whereas the integration of scale distribution and spatial distribution of the cities and towns in the underdeveloped regions is relatively poor,and the development of the primate cities in an "isolated island way" affects the regional development level.