A new coupling evaluation method for human settlement-environment-energy systems: Enhancing residents' happiness

Suitability and coordination of Human Settlements, Environment and Energy (HSEE) system are crucial for regional development and residents' well-being. However, most existing studies have focused on single or dual-coupled systems, neglecting the complex interactions among all three. This study proposes a new evaluation method for coupled system suitability using a more comprehensive HSEE indicator system. The study analyses spatiotemporal evolution and coupling coordination effects based on intelligent algorithms. The results reveal significant geographical and temporal variations in thermal stress levels across China from 2003 to 2023, with cold stress in the west and northeast and increasing thermal stress in the southern and eastern areas. The comprehensive suitability of the HSEE system has improved, with the energy subsystem advancing notably, although the human settlement subsystem still needs attention. Disparities persist, with the eastern coastal regions showing high suitability, whereas the central, western, and northeastern areas require enhanced coordination and policy support. The coupling and coordination between subsystems exhibit spatial gradients, with better coordination in the east and challenges in the northwestern and northeastern regions. This study offers a theoretical foundation for multisystem coupling research. The research findings provide valuable insights for policy-makers to increase regional suitability and improve residents’ well-being.