Study On The Driving Factors And Decoupling Relationship Of The Carbon Effect For Urban Construction Land Expansion In China’s Urban Agglomeration Under The New Normal

China has been undergoing a phase of rapid urbanization,and the extensive urban development model based on the expansion of urban construction land has caused a series of environmental problems.In the face of numerous environmental challenges,the greenhouse effect caused by carbon dioxide emissions is becoming increasingly prominent.Urban construction land is a significant source of carbon dioxide emissions,and its expansion is accompanied by the generation of carbon effects.China’s development stage had entered the "New Normal," and more attention had been paid to sustainability in economic development,which required the realization of low-carbon development.Urban agglomerations serve as not only concentrated areas of economic development but also concentrated areas of urban carbon emissions.However,there is currently a lack of comparative research on the carbon effects of multiple urban agglomerations in China.Therefore,this article studies the driving factors and decoupling relationships of the carbon effects associated with urban construction land expansion in multiple urban agglomerations in China,which is conducive to providing carbon reduction suggestions for urban agglomerations.This article focused on studying 17 urban agglomerations in China.Nighttime light data was used to extract urban construction land,and the urban construction land expansion carbon emission effects were calculated from both ecological and anthropogenic perspectives.Based on the calculation result,the characteristics of urban construction land expansion and its carbon emission effects were analyzed.The spatial autocorrelation of carbon emission effects in urban agglomerations was studied using the global Moran’s I index and the hot and cold spot analysis method.Additionally,an econometric model was constructed to analyze the driving factors of carbon emission effects from urban construction land expansion in urban agglomerations.Finally,the Tapio decoupling model and the catch-up decoupling model were used to study the decoupling relationship between carbon emission effects and economic growth.Research results showed that:(1)Development-oriented urban agglomerations in the central region had a relatively fast expansion rate of urban construction land.Urban agglomerations in the northern coastal areas had a stronger expansion intensity of urban construction land.The hotspots of urban construction land expansion were mainly concentrated in the central and western urban agglomerations.(2)In the carbon effect of urban construction land expansion,the ecological carbon effect and the temporal change of anthropogenic carbon emissions were not synchronized,and the overall spatial pattern was relatively stable.Spatial autocorrelation analysis results indicated that there was spatial clustering of the urban construction land expansion carbon effect in the urban agglomeration.Except for the Yangtze River Delta urban agglomeration and the Pearl River Delta urban agglomeration,which had positive spatial autocorrelation of carbon effect,the rest of the urban agglomerations showed negative spatial autocorrelation.Local hot and cold spot analysis showed that carbon effect hotspots were mainly concentrated in the core cities of urban agglomerations.(3)The analysis of driving factors for Chinese urban agglomerations showed that urban economic development was the main factor affecting the carbon effect of urban construction land expansion in urban agglomerations.the urbanization rate had a positive impact on the carbon effect of most urban agglomerations.the technological level had a suppressive effect on the increase of carbon effect in some urban agglomerations.the impact of population density,degree of openness and investment level on carbon effect varied among different urban agglomerations.the speed of urban construction land expansion exacerbated the increase of carbon effect in urban agglomerations.(4)During the study period,the overall decoupling relationship between the carbon effect of urban construction land expansion and economic growth in Chinese urban agglomerations was mainly characterized by absolute decoupling and relative decoupling.The results of the urban development model divided by decoupling coefficient showed that there were declining development type cities in the northern urban agglomeration,while most of the other cities are dominated by low-carbon development types.The pursuit decoupling relationship showed that there was a relatively high proportion of cities that had not achieved pursuit decoupling,and in the process of catching up with benchmark cities,general cities within urban agglomerations will face greater challenges in terms of economic development and carbon effect governance.