Spatiotemporal Dynamics and Obstacles of Social–Economic–Environmental Coupling Coordination in Inner Mongolia, China

Understanding complex interactions among social, economic, and environmental subsystems is essential for regional comprehensive sustainable development. Nevertheless, existing coupling-coordination studies lack sufficient targeted obstacle diagnosis for resource-dependent ecologically vulnerable regions. Against this background, this paper investigates spatiotemporal dynamics and restrictive obstacles of social–economic–environmental coupling coordination (CC) across Inner Mongolia, China, for the period 2001–2020. Based on an SDG-oriented indicator system, we apply the coupling-coordination degree model, Sen’s slope estimator, Mann–Kendall significance test, and obstacle-degree model to assess CC patterns at provincial and municipal administrative scales. Our results show that the overall CC degree presents a fluctuating upward trend with prominent municipal disparities. While eastern and central municipalities generally attain relatively high CC values, such spatial patterns differ distinctly across pairwise subsystem combinations (social–economic, social–environmental, economic–environmental). Hohhot and Hulunbuir exhibit relatively slow CC improvement, whereas Ulanqab achieves the most prominent growth. At the provincial scale, economic and environmental dimensions constitute major limiting constraints; at the municipal scale, restricted wetland area and low forest coverage act as critical local obstacles. This study further discusses policy implications for ecologically sensitive resource-dependent regions and provides replicable analytical references for comparable territories to advance SDG-aligned sustainability governance.