Empirical Research on the Urban Development Level of Wuhan Urban Circle

The research object of this paper is the nine cities of Wuhan urban circle. Firstly, this paper establishes the comprehensive evaluation indicator system and evaluation model of the urban development level via systems analysis, then makes a PCA (Principal Components Analysis) to the original data by means of SPSS; Next, this paper analyzes the worked data via AHP (Analytic Hierarchy Process) and comprehensive score and ranking of the nine cities is obtained and the nine cities are divided into three clusters via K-means clustering analysis; Finally, this paper appraises urban development level of Wuhan urban circle.


INTRODUCTION
Wuhan urban circle is also known as the "1+8" urban circle, in which the capital of Hubei province: Wuhan municipality is the core city and surrounded by another eight municipalities including Huangshi municipality, Huanggang municipality, Xiaogan municipality, Xianning municipality, Ezhou municipality, Xiantao municipality, Tianmen municipality and Qianjiang municipality.The major strategic decision-making and implementation of "Rise of Central China" provides a good opportunity for the development of Hubei.And Wuhan urban circle is located in the bridge which can connect the four directions, has a strong resource of technology and culture education, and has professional and comprehensive trading market and regional logistics center and traffic transportation hub.Therefore, construction of the Wuhan city circle not only can drive the rapid economy development of Hubei, but also can become the backbone force which drives the rise of central China.
Discussion on the urban development level of the Wuhan urban circle under the background of the rise of central China can provide a basis for making the urban development strategy, which has great significance.Many scholars at home and abroad have studied the problems related to the issues from several aspects (Zhu et al., 2010;Chen, 2005;Luo, 2008;Li, 2009;Ai et al., 2011).On the basis of previous studies, the paper uses methods of principal component analysis and analytic hierarchy process, and combines the quantitative analysis and qualitative analysis combines, studies urban development level of the Wuhan urban circle.

THE COMPREHENSIVE EVALUATION INDICATOR SYSTEM
At present, many scholars from the different fields hold different opinions about the evaluation indicator system of the urban development level.They often establish the indicator system from their own research perspective.Due to the lack of unified definition in the connotation of urbanization and urban development, it is more difficult to make the evaluation and the evaluation results are often inconsistent.The author reviews the extensive literature study to establish the indicator system of urban development level.We think that the composite indicator system is more inclined to be used from the various angles and levels to evaluate and analyze the urban development level.
This article intends to establish a more scientific indicator system from the following five aspects (Ai et al., 2011)   Based on the principles of authenticity, reliability, accuracy, timeliness about data collection and the principles of purpose, scientific, adaptability, comparability and overall system about indicators, an evaluation indicator system which contains five firstlevel indicators, 24 second-level indicators have been constructed (Table 1).

THE COMPREHENSIVE EVALUATION MODEL OF URBAN DEVELOPMENT EVALUATION MODEL
The evaluation model of first-level indicators of wuhan urban circle: During the calculating the development level of the first-level indicators of each city, the evaluation results are often associated with the determination of indicator weight and selection of merger rules.Therefore, the subjective factors have great influence on the evaluation result, and the numbers of each first-level indicator are different and big, which is particularly prominent.So, the principal component analysis method of economic statistics is always used to calculate the development level of each first-level indicator in the urban development evaluation system (Luo and Yang, 2010).
Principal component analysis was put forward by Hotelling in 1933 at first, whose main idea was dimension reduction.It is a multivariate statistical analysis method which can convert the many indicators into a few comprehensive indicators.
So the principal component analysis method is used to determine the weights of a comprehensive evaluation factor in this article, on the basis of which evaluation model will be constructed and the objective function is defined as follows (Zhang and Feng, 2004): where, i = 1, 2, 3, 4, 5；

EMPIRICAL RESEARCH
According to the urban development theory and the actual situation, the original data corresponding to evaluation system of the urban development can be collected.Assuming the vector E represent respectively the number of the second-level indicators responding to their own first-level indicator.In the course of the evaluation of 12 main cities in Hubei, and the following data matrix will be obtained (Chen and Li, 2011): where : 1  1), the score of urban development level of first-level indicator of each city can be calculated, whose results are as shown in Table 2.
The negative values in Table 2 indicate their level is below the average level in all comparison cities, are not the true sense of the negative.If CR<0.1, the results of hierarchical sorting ca satisfy the requirement for consistency, otherwise the judgment matrix will need to be revised.so the matrix A can be solved: As is seen from above, the judgment matrix A satisfies the requirement for consistency check.So the weight among the first-level indicators W1 is acceptable.

Comprehensive
• Comprehensive evaluation: According to Eq. ( 2), total sorting of hierarchy and rank will be obtained, which can be seen in Table 5.Through the analysis At last, the clustering analysis can be performed by the means of K-means clustering method in SPSS software.And it is supposed that the cluster number is 3 and the convergence criteria value is 0.02, the final classification results can be shown in the last column of Table 5.

THE EVALUATION OF CALCULATION RESULTS
According to above statistical data and the results of the analysis by means of our system, nine regions of Wuhan urban circle are sorted into three clusters, of which the urban development level of Wuhan municipality and Huangshi Municipality is higher than the average level of the whole area; other municipalities are also a larger promotion space.
The first cluster: The first cluster includes Wuhan municipality.As the capital city of Hubei Province, every aspect of Wuhan municipality plays the leading role in the overall regions, whose urban development level is higher than that of other cities.By virtue of its special administrative status and a powerful economic strength, Wuhan municipality is the only core growth pole and center of Wuhan urban circle.
The second cluster: The second cluster includes Huangshi municipality, Xiaogan municipality, Huanggang municipality, Xianning municipality.Their situations will be introduced separately: • Huangshi municipality: It has a long history of mining, rich in cultural heritage, a solid industrial foundation, convenient geographical location.As the deputy core city of Wuhan urban circle, the comprehensive score of Huangshi municipality is second only to Wuhan municipality.Huangshi municipality has made outstanding achievements in the opening-up, and its proportion of actual foreign direct investment in GDP is 43.47%, which is the highest of the Wuhan urban circle, and its foreign trade dependence degree is higher, which is secondhighest after Wuhan municipality.Therefore, Huangshi municipality should place emphasis on the export-oriented economy, and achieve balanced development.

CONCLUSION
In this paper, the method of system analysis is used to establish the comprehensive evaluation indicator system and evaluation model of the urban development level evaluation.On this basis of this, the principal component analysis 、analytic hierarchy process and Kmeans clustering algorithm are integrated to evaluate and analyze the development level of nine cities of Wuhan urban circle.Through this research, on one hand urban development level of the Wuhan urban circle can be deeply understudied, which can provide a reliable basis for making urban development strategy of the Wuhan urban circle; on the other hand, the method of data processing and analysis also has practical guiding significance to the urban development level of the Wuhan urban circle.
To determine urban development level index of the first-level indicator:This study uses the descriptive command of SPSS software to standardize the original data, and use the program of dimension reduction to determine the number of principal components and the contribution rate of the principal component of each first-level.And then according to the city development level indicator evaluation model which can be denoted by Eq. ( wuhan urban circle: Based on the above calculation of the principle component, the paper continues to use analytical hierarchy process to determine weights among the first-level indicators and weighted calculation.Finally, we can get the

Table 1 :
The evaluation indicator system of the urban development level

Table 2 :
Principal component score and rank of five first-level indicators 

Table 5
Per capita total retail sales of consumer goods, annual per capita disposable income of rural households, and annual per capita disposable income of urban households of EZhou municipality is second largest in Wuhan urban circle.Therefore, the score in people's lifestyle and living standard is higher, which is second only to Wuhan municipality.The proportion of secondary industry in GDP of EZhou municipality is 58.52%, which is the highest of the Wuhan urban circle.Ezhou municipality should primarily develop the secondary industry, of which metallurgical industry and manufacturing industry is its development advantage.•The other municipalities: Xiantao municipality, Qianjiang municipality, and Tianmen municipality all belong to the county-level city, and their economic development lags behind other cities.But the three municipalities have rich labor resources and are located in Jianghan plain which is the important commodity grain base in China.Therefore, construction of integrated rural development and agricultural industry chain in three municipalities has a clear advantage.