The Coupling Coordination Evolution of Latent Land Use Functions and Its Dynamic Impacts on Carbon Emissions in the Yangtze River Delta

Land use functions (LUFs) are crucial for achieving China’s low-carbon goals, yet their temporal impacts on carbon emissions (CE) remain insufficiently understood. To overcome the limitations of traditional explicit spatial classifications, this study developed an LUF framework based on three implicit functions: development support, development power, and ecological foundation. A comprehensive indicator system comprising 18 indicators was established to evaluate LUFs in the Yangtze River Delta (YRD) from 2005 to 2022. Using continuous time-series data, this study integrated a coupling coordination model, Geographically and Temporally Weighted Regression (GTWR), and Geodetector to examine the interactions among these three functions and their spatiotemporally heterogeneous effects on CE under the influence of multiple socio-ecological factors. The results show that the development support and development power functions show steady upward trends, whereas the ecological foundation function remains stable. The coupling coordination level among the three functions exhibits a spatial pattern characterized by “high in the southeast and low in the northwest,” with the proportions of cities reaching the near disruption and marginally coordinated levels increasing to 41.46% and 17.07%, respectively. Although the development power function remains the primary driver of CE, its positive effect gradually weakens over time. In contrast, both the development support and ecological foundation functions exert significant inhibitory effects on CE. Furthermore, spatial variations in CE are driven by nonlinear interactions between socioeconomic and natural factors, while the dependence of regional CE on urbanization has gradually weakened over time. This study not only elucidates the underlying mechanisms through which LUFs regulate the carbon cycle but also offers a new theoretical framework for land system optimization and targeted carbon emission reduction.