Research on the Associations and Indicative Thresholds of Urban Density on Carbon Performance: A Case Study of Chengdu-Chongqing Urban Agglomeration

Carbon emissions affect sustainable urban development, and cities are the main carbon emission factors. To improve carbon performance from the perspective of urban density, the temporal and spatial evolution characteristics and associations, and indicative thresholds of urban density and carbon performance in the Chengdu-Chongqing urban agglomeration are analyzed by combining Slack Based Measure-Data Envelopment Analysis (SBM-DEA), Standard Deviation Ellipse Analysis, Regression Model, and Spatial Autocorrelation in this paper. The results show that: (1) there is no obvious trend in population density, road density increases faster than building density, and carbon performance shows a decreasing and then increasing trend. (2) The center of gravity of building density and population density migrates towards Chengdu-Chongqing. The road density develops in the southwest-northeast direction, and the spatial pattern of carbon performance shows the characteristic of “high in the southwest and low in the northeast”. (3) The building density, population density, road density, and carbon performance show an upward curve, an “N” curve, and an inverted “N” curve, respectively, and the order of influence is building density > road density > population density. (4) There is a positive spatial correlation between urban density and carbon performance in the Chengdu-Chongqing urban agglomeration, but it is not uniformly distributed, and there is a phenomenon of clustering in specific local areas, especially in the core city areas such as Chengdu.