Spatiotemporal Coupling Analysis of Land Urbanization and Carbon Emissions: A Case Study of Zhejiang Province, China

Urban expansion is one of the most important drivers of carbon emissions. It not only causes the invasion of terrestrial carbon sinks but also aggravates carbon emissions through social and economic activities. Because the effect of urban expansion on carbon emissions varies at different stages of urban development, spatiotemporal analysis of the dynamic relationship between urban expansion and carbon emissions is critical for low-carbon urban planning. By combining nighttime light remote sensing and panel data, this study explored the spatiotemporal coupling characteristics of urban expansion and carbon emissions in a case study of Zhejiang in China. Spatial overlap analysis was used to measure the consistency of the spatial movement trajectories, and the coupling coordination degree model was used to dynamically investigate the interaction between urban land expansion and carbon emission increase. In this way, the dynamic coupling is represented from both a temporal and spatial perspective. The results showed that both the carbon emission and urban expansion growth rates first increased and then decreased, and their spatial coupling became increasingly close. Significantly, the coordinated development level between carbon emissions and urban expansion presented an inverted U-shaped curve, which is consistent with the Kuznets curve theory. Overall, our research revealed the regularity of carbon emissions associated with land urbanization, which can help policymakers and urban planners to achieve sustainable land management.