Relationship and Spatiotemporal Evolution of Resource-Based Urban Mixed Land Use and Carbon Emissions: A Study of 11 Cities in Shanxi Province

Resource-based urban areas face a critical challenge: cutting high carbon emissions from long-term resource exploitation while transforming economically and meeting dual carbon goals. Since mixed land use affects carbon emissions positively and negatively, understanding how to use it for reduction is vital. This study used the entropy method to quantify mixed land use. Carbon emissions were estimated via a carbon metabolism model, linking them to energy consumption and GDP. The decoupling theory model analyzes the land use–carbon emission relationship, while the geographically and temporally weighted regression model reveals their spatiotemporal evolution. Focusing on 11 cities in Shanxi (nearly 90% resource-based), the study found that mixed land use in Shanxi shows significant spatial and temporal variations, promoting and inhibiting carbon emissions. Mixed land use is a double-edged sword; its impact depends on land-use conditions. High-quality mixed land use often inhibits emissions. The land use–carbon emission relationship varies according to city type: Industry-focused cities with rigid structures usually have poor mixed land use that promotes emissions. Coal-extraction cities can achieve better mixed land use through green technologies and policies, thereby inhibiting emissions. Cities with diversified industrial structures often see an intermittent alternation of promotional and inhibitory effects due to unstable mixed land-use quality. Achieving urban carbon emission decoupling often requires industrial and ecological symbiosis, fostering intensive land use and improved mixed land use, thus activating the inhibitory effect. Given these dual effects, land planning policies must be tailored to urban heterogeneity, avoiding a one-size-fits-all approach. This will help quantify and promote mixed land use models that achieve decoupling, empowering resource-based urban areas to harness mixed land use’s inhibitory effect and advance low-carbon goals.