Research On Radiation Range And Capacity Of National Central Cities Based On Gravity Model

With the proposal of a series of China’s urban system planning and setting levels,such as regional central cities and sub-central cities,the national central cities have stood out from all the other levels and have become a new "top-of-the-pyramid" city.These cities enjoy concentrated advantages regarding space,population,resources and policies,and play an important role in stimulating the national economy and strengthening strategic layout.From the development practice of top cities both at home and abroad,it has been found that the higher level that the city occupies in the world urban system,the stronger its agglomeration and radiation capabilities will be,and the more likelihood it will have to seize the commanding heights of the industrial chain and value chain in advance and hence to cultivate its competitive advantage and development initiative.With the proposal and further development of the national central city,how the national central city can enhance its comprehensive strength,promote regional development and represent the national image to become a modern metropolis participating in international competition has become a hot topic for researchers.Zhengzhou city is taken as the major research object in this study.Meanwhile,a comparison is made between Zhengzhou city and the other five national central cities of the same level.According to the theory and method of spatial interaction,on one hand,an index system of the urban comprehensive quality is established,and an entropy method instead of the measurement based on economic gross is used to calculate this quality.On the other hand,the time and route distance needed for the comprehensive transportation network between cities are converted to the comprehensive travel cost in monetary units to represent the accessibility of inter-city transportation,replacing the simple straight distance between the two cities and improving the gravity model used.The improved gravity model is used to calculate the spatial interaction force between six national central cities and other domestic cities.On this basis,the spatial interaction forces of Zhengzhou,Beijing,Shanghai,Tianjin,Wuhan and Xi ’an and other cities are compared and analyzed,so as to define the radiation scope of Zhengzhou city,analyze the influencing factors leading to the different acceptance levels of the radiation capacities of Zhengzhou city,and then,put forward targeted countermeasures to improve the radiation scope and capacity of Zhengzhou city based on the problems existing in the development process of the city.Through the research,the following main conclusions are drawn:(1)The core radiation scope of Zhengzhou includes 23 cities in the Central Plains region,as well as Jining and Xuzhou in other provinces.The vast majority of these cities connected by Zhengzhou are the cities and node cities along the line of the asterisk-shaped high-speed railway network,which have strong inter-city transportation accessibility to Zhengzhou,high comprehensive quality in the central region,and convenient circulation of personnel,goods and materials and other factors.(2)Zhengzhou ranked 13 th among the 292 cities in terms of urban comprehensive quality,which was higher than most cities.Although there is a certain gap between Zhengzhou and the central cities in the economically-developed eastern regions,Zhengzhou indeed has already had due development strength and has its comparative advantages in the central regions.Meanwhile,its comprehensive quality as a national central city is the most important factor to enhance its radiation capability.(3)Zhengzhou,as a national comprehensive transportation hub,relies on the asterisk-shaped highspeed rail network to connect the cities and the node cities along the line,accelerates the development of the comprehensive transportation network in the north-central region,and serves as a pivot in connecting the transportation between the east and the west regions.The inter-city comprehensive transportation accessibility of the national central cities is the basis for the expansion of its radiation scope.(4)As a national central city,the main factors that affect the the acceptance of the radiation of Zhengzhou among the 25 cities in its core radiation range include the transportation accessibility to and from the national central city,the comprehensive quality of the radiated and irradiated cities,the technological innovation ability between the irradiated cities,the quality of people’s life and the difference in the development of public service ability,etc.The development level of scientific and technological innovation ability,people’s quality of life and public service ability of the radiated cities are important drivers for the improvement of the radiated cities’ ability to accept Zhengzhou’s radiation.In the future development of Zhengzhou city,it is necessary to focus on the development of its own strength,build regional transportation integration,reduce city barriers and promote regional industrial integration to stimulate regional integration and enhance the overall strength of the region,so as to accelerate the enhancement of the radiation scope and radiation capacity of Zhengzhou city and realize its ultimate goal of becoming a modern metropolis and competing against other cities in the international competition.(5)The radiation-driven development goal of Zhengzhou city in short period should focus on the central plains urban agglomeration,enhance the connection ability from all aspects and realize the integration of the metropolitan area of the Central Plain region,so as to further integrate the surrounding cities of the metropolitan area as well.