Study On The Coupling Coordinated Development Of The Economy-resource-environment System In Chinese Cities

The degree of coupling and coordination of the economy-resource-environment system determines the sustainable development level of a region.The target of this paper is to reveal the coupling and coordination relationship between society and nature under different natural endowments and socio-economic development stages of Chinese cities,and to summarize the excellent experience of different types of cities in ecological environment conservation and social and economic construction,so as to provide decision support for sustainable development and policy formulation of Chinese cities.This paper takes 340 prefecture-level cities in China as the research object and constructs a panel regression model combining material flow analysis and nighttime lighting to estimate the material stock in major infrastructure at the urban scale and use it as a characterization indicator of a resource system;and then reusing the average biological carbon density method,biological carbon dry weight conversion factor,and land use classification data with a precision of 30 meters,to evaluate the biomass within the cities’ administrative boundaries,and use it as a characterization index of the environmental system;finally,taking GDP per capita as the characterization variable of the economic system to evaluate the coupling and coordination degree of China’s urban economy-resources-environment system and its temporal and spatial evolution during 1990-2020.The main conclusions of the study are as follows:（1）From 1992 to 2019,the material stock of urban infrastructure accumulated rapidly at an average annual rate of 5.0%,and the total amount reached 101.04 billion tons by the end of 2019.Cities in the eastern coastal areas of Beijing Tianjin Hebei,Shandong Peninsula,Yangtze River Delta and Pearl River Delta account for a large proportion of the country’s infrastructure material stock,about 41.6%,and the density of infrastructure material stock in these cities is higher than 800 tons/ha;cities in the central region are behind,and cities in the west and north have relatively low material stocks,with a density not exceeding 100 tons/ha.（2）From 1990 to 2020,the total urban biomass continued to increase by 2709.3Tg,but it showed a different growth distribution in space.The biomass of cities in the northeast and southwest regions is relatively high,accounting for 42.5% of the national total,which is mainly due to their suitable geographical and climatic conditions for biological growth.The polarization trend of biomass density is obvious.The biomass density of the northeast and southern coastal cities is relatively high,exceeding60Mg/ha.The biomass density of the eastern,central and western low-latitude cities is behind,and most cities in the west have relatively low biomass densities below30Mg/ha.（3）After 30 years of development,the coupling degree of economy-resourcesenvironment systems in 94% of Chinese cities has gradually transitioned from a lowcoupling and antagonistic stage to a running-in and high-coupling stage,indicating that the influence between the economic-resource-environment system of most cities is gradually increasing.The coordination degree of cities across the country has been improved,and the coupling coordination status has gradually risen from the low degree in the 1990 s to the stage of moderate and high.And there are significant regional differences between the east and the west.Most of the eastern coastal cities are in the stage of high coupling and coordination,the cities in the central and southwest regions are basically in the stage of moderate coupling and coordination,and most of the cities in the north and west are still in the stage of low coupling and coordination.Based on the above research results,combined with the actual development of Chinese cities from 1990 to 2020 and the strategic development needs of the main functional areas proposed by the state,this paper puts forward countermeasures and suggestions for cities across the country and under different coupling and coordination types,to ensure that the urban economy-resource-environment system can still maintain high-quality development in the process of rapid urbanization.These include accelerating the transformation of industrial structure to stimulate the green growth of the urban economy;steadily improving the quality of urban green infrastructure construction,and reduce the impact of material metabolism on the environmental system through the construction of a circular economy;establishing and improving urban functional zoning and urban ecological space planning;and so on.