Exploring the multilevel coordinated development characteristics and obstacle mechanisms of the smart city–urbanization–low-carbon city system

The rapid urbanization development has led to the deterioration of the urban environment. The construction of smart cities and low-carbon cities aims to improve urban efficiency and promote energy transformation, creating new potential for sustainable urban development and the reduction of urban carbon emissions. This paper constructs a multi-dimensional interactive smart city-urbanization-low-carbon city (SUL) system, using entropy method, coupling coordination degree model, and relative development degree index to analyze the development level of the SUL system and the evolution trend of coupling coordination in China's first-tier cities from 2010 to 2022, and details the relative development status of subsystems. Based on this, the obstacle degree model is used to examine the obstacle factors affecting the development of the SUL system. The results show:(1) During the study period, the comprehensive development levels of subsystems and SUL systems increased overall, despite significant development imbalances among different cities, but these gaps are narrowing continuously.(2) Overall, the coupling coordination level of the SUL system has steadily improved, rising from 0.488 in 2011 to 0.541 in 2022, evolving from a low degree of coupling to a stage of good coordination.(3) Obstacle degree analysis indicates that the obstacle degrees of each subsystem show a fluctuating downward trend, with significant structural differences, and the obstacle degrees are in the order of smart city ​> ​urbanization ​> ​low-carbon city, with mean values of 0.411, 0.319, and 0.270 respectively. In addition, the fluctuations of obstacle factors are significant, indicating that regional development still lacks long-term targeted policies. This study enriches the theoretical framework of multi-system coupling and coordination, and provides a theoretical basis and policy reference for multidimensional collaborative transformation of cities. • Building a comprehensive framework of smart city-urbanization-low-carbon city (SUL). • Exploring the coupling and coordination relationship of SUL system. • Analyze the obstacle factors of the SUL system. • Coordination continues to improve, with significant fluctuations in obstacle factor.