Evolutionary characteristics of spatial correlation network in energy-economy-environment (3E) coupled system and their driving factors, China

Exploring the evolution of correlations within Energy-Economy-Environment (3E) systems and their driving factors is essential for designing effective sustainable development policies. Previous studies have paid limited attention to the spatial correlation evolution of the 3E system from a nationwide perspective based on network structure, particularly in spatial quantification of its influencing factors. Therefore, this study proposes an innovative framework combining coupling coordination degree (CCD), social network analysis (SNA), and explainable machine learning (XML) approaches to analyze the evolutionary characteristics of spatial correlation for the 3E coupling system in China from 2004 to 2022. The results are as follows: 1) The coordinated development level of China's 3E system improves during the study period, although notable regional disparities in CCD persist, displaying a descending trend from eastern to western regions. 2) Over the past 18 years, the spatial correlation within China's 3E coupling system has strengthened, as evidenced by increases in spatial network connections, network density, and the global clustering coefficient. This evolution is accompanied by distinct clustering characteristics. The eastern coastal regions have emerged as major net beneficiary sectors, concentrating resources transferred from the central and western regions, which primarily serve as the main spillover and net spillover sectors. 3) Geographical location, urbanization level, environmental investment, and technological investment significantly impact individual network characteristics, which exhibit evident spatial and temporal heterogeneity. This study establishes a novel research framework for analyzing the coordinated development and driving factors of the 3E system, offering theoretical support for promoting regional sustainable development.