Coupling Coordinated Development of Space-Industry in Central Plains Urban Agglomeration

With the increasing expansion of urban scale and the gradual upgrading of industrial structure, the urbanization level has been continuously promoted. Only by industry and space coordinated development, can the economy be developed rapidly and reasonably, and the quality of urbanization be improved. In recent years, the economic development of central plains urban agglomeration is growing rapidly. However, it is precisely because the central plains urban agglomeration is pursuing the rapid development of the economy, and it has gradually formed a kind of development mode. In this paper, in constructing the index system of urban space and industrial development, using the entropy weight method and the methods of coupling coordination degree model, the measure of central plains urban agglomeration spatial and industrial comprehensive development level and the coupling coordination degree, the results show that most cities are in dissonance. Using vertical analysis, the results show that the spatial pattern centered on Zhengzhou has gradually evolved from the spatial point of view. From the perspective of time series, the urban agglomeration of central plain, the industry is evolving in the fluctuation; the main changes are affected by economic environment and policy. Therefore, several suggestions are proposed for these problems, such as accelerating the industrial upgrading and innovation, scientific distribution and rational use of land, and establishing an innovative mechanism for the coordinated development of industry and space.


Introduction
At present, the Central Plains city group is one of dozens of city groups in China. It belongs to the relatively active region in China's economy, and is also the hub of China's rapid economic development. From 2017 Henan Province, Anhui Province, Shanxi Province, Shandong Province, Hebei Province statistical yearbook data, it can be obtained that by the beginning of 2017, the GDP of the central Plains city cluster was 6193.353 billion yuan, ranking fourth in China after the Yangtze River Delta, the Pearl River Delta and the Beijing-Tianjin-Hebei region. However, since 2014, the central Plains city group has been blindly pursuing rapid urbanization and economic development, while the traditional urbanization has been blindly pursuing large and comprehensive development, which has resulted in the increasingly unbalanced overall development of the central Plains city group, resulting in the decline of economic efficiency, environmental pollution, waste of resources and other increasingly serious problems.
Economist Friedman showed that China is now in a state of excessive urbanization. Urbanization development and urban development capacity should be complementary to each other, and they should develop in a coordinated way.
The excessively rapid development of only one side will often cause many problems. The rapid development of urbanization is not a good thing. It is obvious that the central plains city group is in such a state at present. Therefore, for the central Plains city cluster, the first premise to promote economic development and improve the level of urbanization is to clarify the coordination between urban space and industry. Only the coordinated development of space and industry can achieve the goal of solving the problem.
Under the premise that the economic development and urbanization development of the central Plains city cluster are in imbalance, discussing the spatial-industrial coordination degree and development mode of the central Plains city cluster and discussing their rules will play a guiding role in the economic development and urbanization development of the Central Plains city cluster, and provide reference value for the specific implementation of new urbanization strategy.
Since the 1990s, each region has been paying close attention to its own development indicators such as industry, space and population. Many scholars have different researches on this, with different focuses, objects and scopes, which can be summarized as three points: industrial structure theory, urban spatial structure theory, space-industry-population development coordination theory.  believes that there are two systems in the process of economic development: industry and urbanization. Song (2014) proposed that in the new period, the Central Plains urban agglomeration should give full play to the radiation driving ability and optimize the industrial structure reasonably. Zhang (2015), it is concluded that industrial structure and economic growth interact, and the development of one side promotes the development of the other. Xia and Yang (2005) believe that the premise of balanced development of regional economy should be to solve the problem of spatial coordination. Liu (2015) thinks that although the spatial agglomeration effect of Central Plains urban agglomeration is strong, the diffusion effect is weak. Friedman & Zhou (2007) analyzed and discussed the importance of establishing inter-city network according to the actual situation, and put forward suggestions and emphases for space development. Xu, He, Chen, & Zhang (2016) take Fujian Province as an example to explore the coordination degree of spatial -industry -population coupling in 9 cities of Fujian Province. Zhu & Li (2015) take the Yangtze River Delta urban agglomeration as an example, using the coupling coordination degree model, draw the corresponding conclusions, and put forward reasonable suggestions for the development of urbanization in the Yangtze River Delta region. Zeng and Zhang (2017) take ten urban agglomerations as an example to expand the scope of research, discuss the coordination degree of each urban agglomeration space-industry-population, and compare them, so as to put forward the corresponding conclusions and suggestions.
To sum up, in the space structure theory and the space-industry-population coordinated development theory, foreign researchers rarely mentioned. Taking the central Plains city cluster as the theme to discuss the coordinated development of space-industry, the previous domestic researchers rarely involved. On the basis of previous studies, this paper USES entropy weight method and coupling coordination model to explore the spatial-industrial coupling coordination degree of central Plains city cluster. Through analyzing the coupling coordination degree of the two, problems are found and reasonable Suggestions are put forward.
Although many scholars at home and abroad have done research and analysis on this issue, there are not many researches on the space-industry coupling and coordinated development of central Plains city cluster. The innovation of this paper is that the research object is the central Plains city cluster, not only limited to Henan Province. In the study of the factors affecting the urbanization process, the focus has shifted from resources and environment to the coordinated development of space and industry. By using the coupled coordinated development model, the temporal change of spatial-industrial coupled coordinated development is not only studied, but also studied at the level of spatial pattern. But there are also many shortcomings, such as neglecting the subsystem of the economic system: population. Lack of coordinated analysis of population, space and industry. It can be seen from Table 1 that the total amount of waste water discharged from most cities in Shandong Province, Hebei Province and Henan Province has reached more than 40 million tons, and the discharge of exhaust gas and waste has reached more than 4000 tons, so the air quality is not good. The reason is that the cities of Henan Province, Hebei Province and Shandong Province are mainly developed in the secondary industry in recent years, especially the coal mine resources are rich, many of its industrial enterprises are mainly coal mines, so the overall environment is greatly affected. On the contrary, 5 cities in Anhui province and 2 cities in Shanxi Province have made great efforts to develop new industries and upgrade industrial structure in recent years. The tertiary industry is the main industry, and the water resources are relatively rich. Comparatively, the air quality is better and the environment has been improved.

Characteristics
1) Resource and environment constraints are tightening: For a long time, the central Plains city cluster mainly adopts the extensive economic development model, which is characterized by high investment, high consumption and low income, and is difficult to change in a short time. As can be seen from Table 1 and Table 2, the industrial structure, energy and environmental status of cities in the Central Plains city cluster are very different. Most cities are mainly developed by industrial enterprises with high energy consumption and emission, which leads to resource waste and environmental pollution to a certain extent.
Due to the poor endowment and small quantity of environmental resources, coupled with the accelerating process of industrialization and urbanization, the contradiction of resource and environment carrying capacity bottleneck restricting economic development will become more prominent. Therefore, the protection of resources and environment is still the weak link and urgent task in the economic and social development of the central Plains city cluster.
2) Irrational tertiary industrial structure in the Central Plains city cluster: At present, the central Plains city cluster mainly focuses on the development of the secondary industry, supplemented by the coordinated development of the primary and tertiary industries. Therefore, at the present stage, it is necessary to adjust the structure of the tertiary industry, rationally optimize it, and pay attention to the development of the tertiary industry and the new industry, so that the economy can develop reasonably.
3) Uneven development across regions: Among the 30 cities in the central Plains city cluster, there are obvious differences in the development level between the central city Of Zhengzhou and other cities as well as between each 4) Different industrial structure distribution among cities: Specifically from the distribution of the three industrial structures, Xinyang city has the highest proportion, accounting for 21.9% of GDP, while Zhengzhou has the lowest proportion, accounting for 1.93% of GDP. However, in terms of the development of the secondary industry, hebi city takes the highest proportion, accounting for 65.21% of GDP, and Jiyuan City takes the second place, accounting for 64.97% of GDP. The reason for this situation is that Hebi city and Jiyuan City have a small population, rich steel and coal resources, mainly processing and manufacturing industry, and underdeveloped tertiary industry, which leads to a relatively high proportion of secondary industry. Finally from the perspective of the third industry development, accounting for more than the minimum of Hebei city, accounted for 26.76% of GDP, the highest is in Zhengzhou, accounted for 51.28% of GDP, as the capital city of Henan province, Zhengzhou city, central city Zhongyuan urban agglomeration industrial structure upgrade faster than peripheral city, new industry and third industry development is rapid, the higher the level of economic development natural. As can be seen from Table 2 and Table 3,  As can be seen from

Establishment of Indicator System
In terms of spatial development, previous researchers mainly used indicators such as urban land and green space area to represent the basic situation. Therefore, this paper adopts four indicators: urban land area, urban green space area, per capita road area and urban built-up area. The specific data are shown in Ta-  and tertiary industries in GDP and the number of industrial enterprises are adopted in this paper. The specific data are shown in Table 5.

Data Standardization and Index Weight Determination
The data in this paper are obtained from statistical yearbooks of Henan, Anhui, Shanxi, Shandong and Hebei provinces. Some of the data are directly provided where n represents the number of cities, n represents the number of indicators, represents the ith city's JTH indicator, represents the minimum value of the J item index, and represents the maximum value of the J item index. ij X min j X max j X Therefore, a new dimensionless matrix is obtained.
According to the above formula and the data of various indicators, the calculation results are as follows, as shown in Table 6.

Evaluation Method of Coupling Coordination Degree
By establishing the coupling degree model and finding out the coupling degree, we can know whether the system is coordinated or maladjusted. The coupling degree function formula is (take 2 dimensions as an example):, and is converted to.
( ) Where denotes the industrial development evaluation index and denotes the spatial development evaluation index. 1 U 2 U The value of coupling degree C is 0-1. When C = 1, it indicates that space and industry are completely correlated. When C = 0, it means that the space is completely independent of the industry. However, there are many shortcomings in using coupling degree alone, so the coupling coordination degree model is further proposed.
In order to better study the space-industry coupling coordination relationship, the coupling coordination degree model (taking 2 dimensions as an example) continues to be introduced here, that is, D represents the coupling coordination degree, T represents the composite index, where.

Calculation Results and Main Conclusions
Through the coupling degree model and the coupling coordination degree model, the spatial-industrial coupling coordination degree of the original urban agglomeration is obtained, and the coupling coordination degree is divided into four levels. At that time, it showed that the central Plains city group and each city were in a highly disordered stage.  coordination degree of the two is higher, and the coupling degree has reached more than 90%. there are great differences in the coupling coordination degree of the central Plains city group and various cities. As a whole, the coupling de-gree of Central Plains urban group is 0.42854, which is in the stage of mild imbalance.

R <
According to the above data and the hierarchical division of coupling coordination degree, the 30 cities in the Central Plains city cluster can be divided into the following four types:

1) Highly maladjusted class
There are puyang city, Changzhi City, Jincheng city and Xingtai City in the stage of high disorder. This shows that the space and industrial development of these four cities have serious dissonance. The main reason for this phenomenon is that the economic development of these cities is slow. At the same time, under the constraints of resources and environment, they pay attention to environmental protection and resource conservation, which inevitably leads to the loss of one city and the loss of the other.

2) Mild disorder
In the stage of mild disorder of city of pingdingshan, anyang, hebi city, shangqiu, xinxiang, the authors, jiaozuo, luohe city, zhoukou city, sanmenxia city, huaibei city, handan city, 12 cities, they are distributed in the adjacent area of zhengzhou city, the central city of radiation effect is good, good industrial development foundation, but spatial development relative lag, the coupling coordination degree is low.
These cities are constantly optimizing in all aspects, showing a reasonable structure initially, but also laid a foundation for the coordinated development of the economy.

4) Highly coordinated classes
The city in the highly coordinated stage is Zhengzhou, which indicates that both urban space and industrial development have reached a high level, and their coordination degree is high, with the coupling degree reaching more than 90%. It can be seen that Zhengzhou has a great advantage in spatial-industrial coordinated development. As a central city, Zhengzhou has a solid foundation of space and industrial development, and its degree of coupling coordination is higher than other cities.     the central Plains city cluster recovered rapidly and the degree of system coordination increased. However, the degree of coupling and coordination between space and industry is still relatively low, which also becomes the main contradiction restricting the spatial-industrial coordinated development of central Plains city cluster. It can be seen from the above conclusions that the central Plains city cluster is in a state of mild coordination. The sound development of urbanization cannot be separated from the coordinated development of space-industry. Each city in the central Plains city cluster should pay attention to the coordinated development of space-industry, accelerate industrial upgrading and innovation, scientifically distribute and rationally utilize land, so that the space-industry can develop in a balanced way, so as to promote the further development of urbanization and economy.

Conclusions and Suggestions
Although the Central Plains urban agglomeration in recent years is dominated by industrial development, it also promotes economic development. However, according to the calculation, with the acceleration of urbanization, the coupling coordination degree between space and industry in Central Plains urban agglomeration is at the level of barely coordination, and more problems and contradictions appear. Therefore, in order to further improve the quality of economic development and the level of urbanization, governments at all levels should actively formulate plans and take reasonable policy measures.

Accelerate Industrial Upgrading and Innovation
On the whole, it is pointed out in the 2016 Central Plains city cluster development plan that the central Plains city cluster should be upgraded into a national advanced manufacturing and service industry base as well as a demonstration area for green ecological development. The proportion of the tertiary industry and emerging industries should be increased and the tertiary industry should be developed intensively. Therefore, the central Plains city cluster should actively carry out industrial upgrading and innovation. As for the past structural model, we should continue to retain and adhere to the good things, and should transform and upgrade those that deviate from the current economic development model.
In the process of industrial upgrading and innovation, the market plays an important role. However, in terms of the market mechanism, the central Plains city cluster is in the primary stage, and the market mechanism is not perfect. Therefore, the central Plains city group should perfect the market mechanism, improve the competitiveness, so as to promote the development of the market economy. In the process of improving the market mechanism, it is necessary to summarize the experience of developed countries, combine with the market situation of China, and use certain technologies to improve the market mechanism and realize the industrial upgrading and innovation of the central Plains city cluster. In the aspect of enterprise, innovation and upgrading of enterprise difficulty is bigger, and the emphasis and difficulty in urban industrial structure optimization innovation, governments at all levels to enterprises in the industrial upgrading, technological innovation and market expansion to give greater support, so as to promote enterprise innovation and industry upgrading, stable economic development. At the same time, in addition to government support, enterprises' own innovation and upgrading are also the top priorities. Therefore, enterprises should cultivate their own innovation ability, independent research and development, improve their comprehensive strength, and realize industrial upgrading and innovation in the central Plains city cluster. In the process of industrial upgrading and innovation, we should combine the market with the government, make full use of industrial policies as guidance, strengthen the capacity of independent innovation, and change the previous extensive development mode into intensive development mode.

Scientific Layout and Rational Use of Land
At present, with the increasing contradiction between supply and demand of land in China, strengthening land management and scientific use of land have become the fundamental approach and inevitable choice to solve this problem.
To a certain extent, the government should enhance the consciousness of innovation, change the space design, scientifically arrange the urban space, rationally use the land, and make the urban land more sustainable development. In terms of land use, the government should clarify the total amount of land, appropriately control the scale of land use and formulate reasonable land use policies.
At the same time, the government should strengthen legislation to make land use policy more authoritative. In the scientific and rational use of urban space, the role of land administration departments should be brought into play. Administrative departments should fully investigate all aspects of land, understand the problems and deficiencies of land use, understand the functions of land in different areas, and tap the potential, so as to make a scientific layout, formulate the best development and utilization plan, and give full play to the maximum benefits of land.

Establish an Innovation Mechanism for the Coordinated Development of Space and Industry
The government should take space and industry into consideration when for-mulating the urban development plan. The result of the adjustment of industrial structure will finally be presented in the form of space, which will also affect the result of spatial optimization. Therefore, the relevant policies should be considered and implemented at the same time in order to solve these two problems comprehensively. The improvement of industrial level will promote economic growth and urban development. Once the city develops too fast and has a certain competitiveness, the labor force and capital will increase, leading to further development of space, and thus providing more space for industrial development.
If the spatial development stagnates, it will also have a certain influence on the industrial development, which will inevitably affect the comprehensive development level of the city. Therefore, the government should give more rights of urban development to the market, supervise the service market, make industrial development and spatial development complement and influence each other, make industrial development drive spatial development, spatial development promote industrial development, and establish an innovative mechanism for coordinated development of space and industry.

Conflicts of Interest
The author declares no conflicts of interest regarding the publication of this paper.