Resource-based cities (RBCs) are pivotal regions for China to achieve low-carbon development, and their transition performance is closely linked to territorial space development and protection (TSDP). To scientifically assess their sustainable development levels, this study constructed a comprehensive evaluation system for territorial space development and protection level (TSDPL), encompassing dual dimensions of development and protection. Based on panel data from 110 Chinese RBCs between 2005 and 2020, we systematically measured the spatiotemporal evolution of TSDPL for each city. The findings reveal that the TSDPL increased at an average annual rate of 2.791% during the period. However, the protection level consistently lagged behind the development intensity, reflecting an overall characteristic of prioritizing development over protection. Spatially, TSDPL exhibited a gradient differentiation pattern of being "higher in the southeast and lower in the northwest." Its center of gravity shifted approximately 51 km to the southwest, forming "high-high" agglomeration areas represented by Shandong and Jiangsu provinces and "low-low" agglomeration areas represented by Gansu Province. The absolute disparity in TSDPL among cities continued to widen, indicating a pronounced polarization trend. The research further uncovered significant heterogeneity in the transition outcomes: regenerative type cities, non-metallic-based cities, and those in the eastern region performed better, while growth type cities, forestry-based cities, and those in the western region lagged relatively behind. This suggests that under similar resource constraints, local development pathways and governance efficacy are key determinants of transition outcomes. By establishing a nationwide comprehensive TSDPL measurement framework, this study systematically identified the differentiated transition trajectories of RBCs across various development stages, dominant resource types, and regional contexts. It provides a scientific basis for implementing categorized guidance and targeted policies for low-carbon transition and spatial governance.
Ji et al. (Sun,) studied this question.