Study On The Organizational Structure And Evolution Of Urban System In The Yangtze River Economic Belt

As the development of new-type urbanization in the Yangtze River Economic Belt enters a higher level,the study of the evolution of the combined structure of urban systems has important theoretical and practical significance.The rapid development of urbanization has accelerated the establishment of the urban system,which is an urban group organization of various types,different levels,and close spatial interaction in the region.Urban system research generally includes four aspects: the spatial and temporal distribution of urban systems,the interconnections between cities and their networks,the hierarchical structure of urban systems,and the functional structure of urban systems.At the end of 2018,the average urbanization rate of 9 provinces and 2 municipalities in the Yangtze River Economic Belt was 59.46%.The urban system has been initially established.As far as the combination is concerned,it has obvious organizational structure characteristics.In this paper,by sorting out the evolution of urbanization and the urban system in the Yangtze River Economic Belt,the spatial-temporal differentiation of the Yangtze River Economic Belt's urban system is obtained.The Yangtze River Economic Belt's urban system generally exhibits a gradient of east,middle,and west development and a gradual spread from the regional center to the periphery.In the future,the urbanization development of the Yangtze River Economic Belt will expand in the direction of regional integration from axes and belts to points and areas.Analyzing the evolution of hierarchical scale structure,this paper considers that the formation of spindle shapes in large,medium and small cities is an ideal structural distribution.In the Yangtze River Economic Belt,there are cases of hierarchical scale structure faults.It is necessary to speed up the construction of type I large cities with a population scale of 3 to 5 million and promote the evolution of the hierarchical structure of the urban system to a spindle shape.Based on the modified gravity model,the provincial and prefecture-level regional social network maps of the Yangtze River Economic Belt are obtained.After analysis of the correlation,core edge structure,and centrality,this article considers that the Yangtze River Economic Belt has a high social network density,strong correlation,and regional coordination basis Well,macroscopically,the upstream,middle and lower reaches are separated,and cooperation between upstream and downstream should be strengthened.However,the network efficiency of the Yangtze River Economic Belt is low,the hierarchy is unknown,and the spillover effect is blocked.The social networks of prefecture-level divisions are complicated.The core position of the central city needs to be strengthened,and the conduction channel is not obvious.We should focus on strengthening the centrality and intermediate centrality Tall cities give full play to the "bridge" transmission effect.The hierarchical structure is an important feature of the urban system,and the clustered distribution is also a manifestation of the highly developed urban system.This paper measures the distribution of the first place in the Yangtze River economic belt by region,and performs a scale-rank regression analysis.The results show that the hierarchical structure of the upper reaches of the Yangtze River,which is a little behind the level of economic development and urbanization,has gradually evolved into a concentration,and the regional development model has tended to focus on cultivating the Chengdu-Chongqing metropolitan area in a diffusion strategy.The evolution trend of the city's top rate in the middle reaches of the region fluctuates greatly,in part due to changes in the statistical caliber within the time frame of the study.However,from the indicators of the top cities in the four cities and the eleven cities,it can still be concluded that they have aggregated,diffused,and redistributed The conclusion of the gathering is that the urban development of the middle reaches was once stuck in “stagflation”.Based on the existing urbanization and urban system,it should rely on industrial upgrading and population migration to consolidate regional advantages to regain its growth vitality.The value of |-q | in the downstream area is relatively stable,the adjustment of the population size tends to ease,and the urban system has been adjusted from excessive concentration to a state close to the ideal hierarchical structure.This article analyzes the scale and intensity of the ten major functions of the Yangtze River Economic Belt.From the perspectives of location entropy and Nelson index classification,the ten major functions of the three regions of the Yangtze River Economic Belt are measured and aggregated.Mining functions are scattered in the Yangtze River Economic Belt,and the overall hierarchy is unknown.The deep processing facilities and the linkage between upstream and downstream industries need to be further strengthened.Industrial functions are clearly clustered along the coast and gradually spread to the middle reaches.The functions of the construction industry show the distribution of the word “Chuan” in the north and south.The transportation and communication function is a function that has advantages over the whole country in the Yangtze River Economic Belt.However,only Shanghai in the Yangtze River Economic Belt has absolute advantages in the entire region.The hierarchical system of transportation and communication functions needs to be improved.The commercial functions are stronger in the middle reaches,and the financial service functions are still concentrated in the downstream Jiangsu and Zhejiang areas,but there is also internal competition.The cultivation of financial service functions in the upper and middle reaches should be strengthened.There is a tendency for the real estate function to sink and spread in mid-upper-stream and second-and third-tier cities,and even to border cities.Scientific research management is a dominant function of the Yangtze River Economic Belt,but there is no trend of continuous or band-shaped proliferation.Administrative functions and social service functions have their own characteristics.Due to inefficiency and national policies such as western development and targeted poverty alleviation,the functional portfolio structure has become more It is complicated and a large number of employees gather in remote and backward areas.It is believed that the efficiency of administrative and social service functions in the Yangtze River Economic Belt needs to be strengthened.