Research On City Compactness And Urban Efficiency Of Urban Agglomeration In The Middle Reaches Of Yangtze River

In recent years,the problem of urban expansion in our country has become increasingly prominent,and there are many problems in the process of urban development.Compact city is considered to be energy-saving,sustainable,efficient,and environmentally-friendly modes of urban development and have important guiding significance for the development of new urbanization.In this paper,the entropy method was used to study the urban compactness changes in the middle reaches of the Yangtze River in urban areas from 2011 to 2015.The results show that the urban agglomerations in the middle reaches of the Yangtze River have been on the rise from 2011 to 2015.At the same time,this paper adopts a super-efficient DEA model to analyze the changes in the efficiency of 31 cities in the middle reaches of the Yangtze River from 2011 to 2015,and then explores the correlation between the compactness and the urban efficiency.Finally,based on the analysis of the influencing factors of compactness changes,the article puts forward suggestions for promoting the compact development of the urban group in the middle reaches of the Yangtze River.In the analysis of the compactness of urban agglomerations in the middle reaches of the Yangtze River,this paper selects compactness of land use,economic,population,infrastructure,public services,and degree of eco-environment coordination as six perspectives.The 17 indexes were used to construct a comprehensive measure index system for the compactness.The entropy method was used to calculate the weights and comprehensive scores of the indicators.The calculation results show that the compactness of urban agglomerations in the middle reaches of the Yangtze River continued to rise from 2011 to 2015.Based on this,the paper analyzes the temporal and spatial characteristics of the compactness changes in the middle reaches of the Yangtze River.In the analysis of the correlation between urban compactness and urban efficiency in the middle reaches of the Yangtze River,we first set up a measurement index system for urban efficiencies,mainly include the urban construction land area,the number of employees in the secondary and tertiary industries in the urban area,and the investment in fixed assets in the entire society as input indicators.Select the output value of the secondary and tertiary industries,the retail sales per capita of social consumer goods,and the per capita green area as the output indicators,the super efficiency model is used to measure the urban efficiency.Secondly,according to the measurement results,the correlation between urban compactness and urban efficiency is studied by using the analysis function of the coupling coordination model.The results of the study show that there is no obvious synchronization between the compactness and urban efficiencies of cities in the middle reaches of the Yangtze River.Finally,based on the analysis of compactness and urban efficiency,the paper used qualitative and quantitative methods to study the influencing factors of compactness,and put forward suggestions for promoting the compact development of the middle reaches ofthe Yangtze River.