改革开放以来中国地级市设置的空间特征及存在问题

The establishment of prefecture-level cities is a major spatial achievement of the social structure transformation in the process of modernization in China. The optimization of the layout structure of such cities is an inherent requirement for deepening supply-side structural reform and is of great significance to the construction of a scientific and reasonable urbanization pattern. Using the district similarity coefficient and standard deviation ellipse model, this study discusses the spatial characteristics and existing problems of prefecture-level city setting. The results reveal the following: 1) In terms of spatial characteristics, since the reform and opening-up, the setting of prefecture-level cities in China has been greatly affected by policy factors, exhibiting a gradual trend of advancing from east to west and from coastal to inland. 2) After reform and opening-up, the addition of prefecture-level cities is an adjustment on the basis of the original regional system, including the establishment of a city, the merger of a city, promotion of a county or county-level city to a city, and so on. 3) With the development of economy and society, the "space" problem of the prefecture-level city setting has become increasingly prominent, which is closely related to the difference in the mode of city setting, resulting in the administrative centers above prefecture-level setting too close, "small horse and big cart" and other problems to varying degrees. 4) The spatial distribution of prefecture-level cities in China is generated in regional administrative districts against the background of industrialization and urbanization, developed in the strategic transformation of urban-rural differences and cross-border cooperation, and faced with the innovative challenge of regionalization adjustment in the process of regional restructuring and scale restructuring. 5) The "space" problem leads to the increase of the system cost of economic and social development to varying degrees. Therefore, the layout of productivity should be comprehensively considered in a wider scope, and the adjustment of prefecture-level administrative divisions can be carried out when necessary. The possible contribution of this study to the literature is reflected in the application of the similarity coefficient of administrative districts to reveal that "the prefecture-level city is highly similar to the original region." Moreover, the problems existing in the current setting are related to this, such as too close distance and call for great importance to the significance of the adjustment of administrative divisions of the prefecture-level city. The possible shortcomings are that the logic of such city administrative division adjustment needs to be further explored, and the analysis of the thinking path of this adjustment is insufficient. In the future, the research on relevant issues in prefecture-level cities should be strengthened. Additionally, it is necessary to change the thinking of the adjustment of the overall construction system and the internal adjustment of prefecture-level government districts, consider the layout of productive forces from a broader perspective, consider the level of administration, the scale of government districts and the spatial structure as a whole, and take comprehensive measures to meet the actual needs of national and local development.