Evaluation Of Ecological Efficiency And Study On Influencing Factors Of Urban Agglomeration In The Middle Reaches Of Yangtze River

With the advancement of new urbanization and the strengthening of regional connections,China has gradually formed a spatial development pattern centered on urban agglomerations.The urban agglomeration in the middle reaches of the Yangtze River is an important urban agglomeration of the country.Its development plays an important role in the development of the Yangtze River Economic Belt and the country.With the rapid development of urban agglomerations,the contradiction between economic development and ecological environment has become increasingly prominent.As one of the important tools for measuring regional sustainable development,ecological efficiency provides an evaluation path for analyzing economic growth and ecological and environmental problems.Studying the ecological efficiency of the urban agglomeration is of great significance to the construction of regional ecological civilization,improvement of the ecological environment and sustainable development of the region.Based on the panel data of 31 cities from 2007 to 2017,this paper builds an eco-efficiency evaluation index system which based on the principle of input and output,and uses the DEA(Data Envelopment Analysis)model to conduct a static analysis of the eco-efficiency multi-scale;Then uses the Malmquist index and its second decomposition model to dynamically analyze the ecological efficiency;Then uses theTheil index to analyze the regional differences in the ecological efficiency;Finally,we constructs the evaluation index system of influencing factors uses GeoDetector Software to analyze the impact factor of ecological efficiency.The main research conclusions are as follows:(1)From a static analysis point of view,the ecological efficiency has increased in fluctuations,from 0.670 in 2007 to 0.858 in 2017,with an average annual value of 0.770,reaching 77% of the ideal state,and there is a larger room for improvement.The eco-efficiency of the three sub-city clusters showed differentrising trends and had obvious differences.The average eco-efficiency of the Changsha-ZhuZhou-XiangTan urban agglomeration was the highest,followed by the PoYang Lack urban agglomeration,and the Wuhan urban agglomeration was the lowest.The spatial evolution characteristic of ecological efficiency in 31 cities is obvious,and the development between cities is uneven.The ecological efficiency of Changsha city and Huanggang city are the best,and the DEA is effective for 11 consecutive years.The ecological efficiency of Jingdezhen city,Huangshi city and Ezhou city is the lowest.(2)From a dynamic analysis point of view,the Malmquist indices grew at an average annual rate of 13.9% from 2007 to 2017,and the Malmquist indices of the three sub-city groups were all greater than 1,of which Wuhan urban agglomeration(1.153)> Changsha-Zhuzhou-Xiangtan Urban agglomeration(1.151)> Poyang Lake urban agglomeration(1.116).Among the 31 cities,Changsha city has the largest Malmquist index.From the perspective of secondary decomposition,both technological efficiency changes index and technological progress changes index can cause the growth of the Malmquist index.Among them,the increase in technological progress change index is the main driving force for the improvement of total factor productivity.(3)From the perspective of regional differences,the overall Theil index of eco-efficiency has declined in fluctuations,indicating that the regional differences in eco-efficiency are shrinking.Differences among sub-city groups are expanding,and differences within sub-city groups are converging.From the perspective of contribution rate,the intra-group difference is much larger than the inter-group difference,which is the main reason for the regional differences in ecological efficiency.(4)From the perspective of influencing factors,the most significant influencing factors for the ecological efficiency is the industrial structure,the more significant are the population size,scientific research intensity and urbanization level,and the least significant is the urban greening level.After the interaction of influencing factors,the explanatory power of ecological efficiency is enhanced,and the interaction of two factors is greater than the single factor.