Analysis Of The Impact Of Urban External Economic Environment And The Prediction Of Central Cities

Urban development is a critical component of modern economic growth and is both driven and constrained by its own factors and interactions between cities.Quantitatively analyzing the process of urban development and inter-city interactions is a significant issue for scholars.This thesis defines the impact of each city from other cities based on the theoretical hypothesis of the gravity model from an economic connectivity perspective.It constructs an index named“external economic impact field strength”that is not directly related to the city’s own economy to describe the external economic environment that affects urban development.The main work of this thesis includes:ⅰ)Based on the gravity model,two indicators that describe the external economic environment impact(“total external economic impact field strength”and“Zipf distribution index of external economic impact field strength”)are constructed a priori.These indicators have no direct relationship with the city’s own economic indicators but show a strong correlation with them.They also reflect the economic connectivity of spatial links between cities in the formula.ii)Through external economic environment impact indicators,external environmental factors that affect urban development can be better separated.By taking the annual average change of the external economic environment impact indicators as the independent variable and the annual average change of the city’s gross domestic product as the dependent variable for regression analysis,the results show that more than 50%of the proportion(R~2=0.515)of the growth of the city’s total economy can be explained by changes in the total external economic impact field strength and the Zipf distribution index of external economic impact field strength.This reveals that changes in the external economic environment of cities have a strong impact on urban economic development.In addition,by subtracting the growth rate of a city’s real gross domestic product from its predicted value,an internal driving force index for urban development is obtained.By analyzing the relationship between this internal driving force index at the level of first-level administrative regions and economic characteristics and transfer payments,a brief quantitative analysis of the relationship between non-external influence factors and economic development is conducted.iii)To study the shaping of the current urban economic development status by spatial economic connectivity or spatial interaction between cities,this thesis calculates the local Moran index for each city based on GDP,the total external economic impact field strength and the Zipf distribution index of external economic impact field strength.These local Moran indices and the indicators they are based on show different trends in development for cities of different sizes in the truncated distribution of correlation with annual average change(divided into four groups with the highest correlation for cities of different economic scales).By mining the deviation angle of the fitting curve direction of each city’s relative local Moran index,this different trend is also well reflected at the level of first-level administrative regions.iv)Based on the balance shown in the distribution of external economic environment impact indicators between the government seat within the city and its subordinate hinterland,this thesis defines the“local centrality of external economic impact”indicator to describe the importance of counties or cities within their respective cities or provinces.Based on this,this thesis makes predictions for the central areas within the city and province respectively from the perspective of external economic environment,providing a new external perspective for traditional judgment methods.It also explores the explanatory power of external economic environment impact indicators for existing central cities under different gravity model distance decay coefficients.Based on the gravity model,this thesis proposes some indicators that can reflect the impact of external economic environment.They show their adaptability and innovation in many aspects,such as explaining urban economic scale,discovering urban development characteristics,deepening understanding of collaborative development,predicting central areas within cities from a new perspective and optimizing distance decay coefficients.Through empirical analysis,this study provides methodological innovation for urban science,complexity science and spatial interaction and contributes to a more scientific understanding of the driving forces behind urban development.