Theoretical Research And Empirical Analysis Of City Optimal Size Based On The Eco-city

At present, China is in a period of rapid development of urbanization, which means the rapid increase in city population scale and the sharp expansion of city space scale. The rapid growth of the city size, on the one hand, can promote the development of city economy, improve the city's competitiveness; while on the other hand, it produced some city problems such as the tension, overcrowded housing, traffic congestion, environmental pollution and resource shortages. How to find the city optimal size which both to ensure the sustained and rapid economic growth of the city and not to lead to the city problems—that are the key problems for our country urbanization construction in the21st century.By researching this topic, can obtain a more comprehensive and in-depth understanding of influence mechanism and laws which affect the city effective size, establish a city effective size solution based on eco-city model, analyze and judge the reasonableness of present city size, further guide the development of the city. This research has important significance to guide and control of the city size and will provide a scientific basis for the policy-makers of the city.Based on the research background and status quo of the development of the ecological city theory and practice analysis, illustrates the purpose and significance of this study, and puts forward the scientific method to study the city optimal size from the perspective of eco-city.This paper first reviews the theoretical and empirical process of city optimal size of cities at home and abroad, and reveals the shortcomings of traditional research methods which pay attention to the research of city within the system without considering the external environment impact on the city optimal size. For the first time, this paper analyzes the city optimal size from the perspective of ecological city. Then concludes that the city optimal size not only depends on the elements within the system, and more depends on its city network connection degree and the function in urban network system. This conclusion is the foundation of the paper behind.Application of ecological city theory, the paper studies of the city optimal size. The paper analyses the affecting elements of the city optimal scale and clarifies the conclusion that the city optimal size is determined by the city and the system environment of system elements. And construct three mathematical models of city optimal size, respectively based on within the city system, the city system environment and the eco-city system.In order to facilitate the practice of the mathematical models, the paper builds two systems based on an integrated, representativeness, comparability and operational hierarchy. And empower the indicators by using Delphi method. Using EViews software, the paper builds three mathematical models of Qingdao city through the relevant data and concludes its optimal size and effective size from different perspective. And according to the current situation of the development of Qingdao city, puts forward the countermeasures for future development.This paper draws on urban ecology, urban economics, social science and other fields of existing research results. Guided by the systems theory, the paper adopts the combination of qualitative analysis and quantitative analysis, combining induction and deduction, combining the theoretical analysis and empirical analysis and other methods. With urbanization in the background, this paper construct the optimal scale is based on the analysis of the ecological city urban research framework.