Study On Functional Polycentric Spatial Structure Of Urban Agglomerations In China

Since the reform and opening up,the rapid development of urbanization in China has promoted the development of economy,but it also brought a series of "urban disease" problems,such as unreasonable spatial distribution,regional development is not coordinated.For this reason,the National New Urban Planning(2014-2020)issued by The State Council in 2014 proposed the development policy of centering on human urbanization and taking urban agglomerations as the main form,which comprehensively promoted the rapid progress of urban agglomerations.Urban agglomerations are important carriers of China’s economic development.In more than40 years of reform and opening up,China has formed a strategic layout of urbanization with two horizontal and three vertical,and planned and built 19 urban agglomerations.By the end of 2019,The State Council had approved 10 city clusters,including the Yangtze River Delta,The Beijing-Tianjin-Hebei region,the Guangdong-Hong Kong-Macao Greater Bay Area(formerly known as the Pearl River Delta),the middle reaches of the Yangtze River,and the Chengdu-Chongqing city cluster,as well as the Guangdong-Fujian and Zhejiang city clusters,the Central Plains,the Guanzhong Plain,the Huohu,Baotou,Eryu and Lanxi city clusters that still need to grow.In China,urban agglomeration is not only the main body and center of regional economic development,but also an important contributor to national economic and social development.By the end of 2019,China’s top 10 national-level urban agglomerations had gathered 62.5 percent of the population and created 73.2percent of the economy,covering 33.46 percent of the country’s land area.Compared with 1980,China’s urban agglomeration has achieved a leap forward in development,with the total population increasing by 58 percent and the total economic volume increasing by nearly 600 percent.Different from the traditional provincial level research,urban agglomeration is usually a collection of several geographically adjacent cities in different provinces.In the initial stage of urban agglomeration planning,urban agglomeration often presents a monocentric spatial structure with a megacity as the core.However,with the exchange and acceleration of various "flows" such as human flow,information flow and capital flow between cities,the functional interaction within urban agglomeration is significantly enhanced,and the characteristics of multi-centers are becoming more and more obvious.Urban agglomeration is actually a kind of multi-center,cross-administrative regional organization of urbanization.Compared with the spatial centralization of the single center structure,the multi-center spatial structure should be regarded as a kind of "centralized decentralization".The polycentric spatial structure is essentially the product of the continuous expansion and spread of the city.When the urban population grows rapidly,in order to avoid the negative effects caused by excessive expansion,the city will break from the single-centric spatial structure into the polycentric spatial structure and obtain higher economic performance.However,multi-centrality in space is not only highly complex and difficult to control,but also may produce strong superposition effect through network connection.Therefore,its influence on economic development is more complex and difficult to predict.Research on the spatial structure of urban agglomerations in China started relatively late.The initial research mainly focused on the identification and judgment of the spatial structure of urban agglomerations,usually using the rank difference measurement of population data to determine the single and polycentric structure of urban agglomerations from the morphological dimension.Later,the research was extended to the spatial structure and economic development.However,studies based on this dimension still take isolated cities as the object and take agglomeration economy and scale economy as the basis to analyze the rational allocation of spatial resources,lacking the analysis and investigation of the relationship within urban agglomerations,and unable to conduct in-depth discussion on the interaction mechanism between cities.In the context of the current rapid development of "flow space",different levels of networks have been formed within urban agglomerations,and the role of network externality has been gradually enhanced,and to a certain extent,it has replaced the inter-city agglomeration externality,affecting the economic development of the entire urban agglomerations.Therefore,this paper mainly analyzes the impact of functional multi-center spatial structure on the economic growth,coordinated development and innovation performance of urban agglomerations from the perspective of traffic inflow.The findings are as follows:First,most of the urban agglomeration in China has been basically formed functional polycentric structure and are evolving to the functional polycentric structure at different speeds.The second and third industry cluster and the change of employment structure will be a different impact on polycentric spatial structure,therefore,can be used to influence the spatial structure of urban agglomeration.Second,polycentric spatial structure,the function between cities can use various forms of network use scale and use function,and to a certain extent,avoid excessive competition brought about by the shadow of gathering,raise the economic performance of the whole urban agglomeration and economic efficiency,scale and small urban agglomeration in the borrow and borrow the functional effect is stronger.Third,functional polycentric structure can promote high-level urban agglomeration of industrial structure,promote urban agglomeration degree of specialization.Through the two kinds of mechanisms it can reduce the economic gap between the city and promote the coordinated development of urban agglomerations,but increased fiscal spending inhibits the function of economic gap between the convergence process of specialization.Fourthly,under the functional polycentric spatial structure,cities can consolidate knowledge spillover through borrowing scale,and avoid the knowledge solidification effect caused by excessive proximity to some extent,thus promoting the increase of the overall innovation performance and per capita innovation output of urban agglomeration.When the degree of functional polycentricity is low,it can promote the development of urban agglomeration to the direction of innovation polycentricity,or else,it can inhibit the formation of innovation polycentricity spatial structure.Based on the research conclusions of this paper,it can be found that China’s urban agglomerations are still in the initial and rapid growth stage of functional multi-center,and the connection and interaction between cities still have obvious provincial characteristics and regional differences.Therefore,the development of urban agglomerations in the future still needs to take measures according to local conditions and be guided by classification.Functional multi-center spatial structure has achieved preliminary results in promoting the economic growth and coordinated development of urban agglomeration,which also indicates that the construction of functional network is reasonable and necessary.However,the construction of urban agglomeration in the future should still be guided by economic policies,fully consider the crystal structure and development law of urban agglomeration,take geographers as high-end think tank and combine with advanced simulation decision-making system to develop and expand continuously on the basis of natural partition,and drive the economic progress of urban agglomeration and even the whole country.