Analysis of the Evolution of Land Use Carbon Metabolism Patterns and the Response to Urban Form Changes in Haikou, China

It is increasingly recognized that urban planning is essential in promoting low-carbon urban development, and the research on urban carbon metabolism patterns informs the theoretical support for carbon neutrality through urban structural optimization. To investigate the correlation between carbon metabolism patterns and urban form, this study analyzes their spatiotemporal evolution, thereby informing low-carbon urban planning from a novel perspective. Using multi-temporal land use data from 2000 to 2025 in Haikou City, China, we calculated carbon emissions and sinks based on land use types, and applied GIS spatial analysis, landscape metrics and autocorrelation methods to reveal the dynamic relationship between urban form and carbon metabolism. The results indicate that, over the past 20 years, carbon emission areas in Haikou have continuously expanded, with high-emission zones clustering in the city center, while carbon sink areas have gradually contracted and become increasingly fragmented. In terms of response, there is a notable correlation between the evolution of carbon metabolism patterns and the changes in urban form. In High–High (HH) carbon emission clusters, the degree of aggregation is positively correlated with urban morphological complexity, which indicates that greater complexity leads to stronger clustering of carbon emissions. In contrast, for carbon sink areas, higher morphological complexity corresponds to lower aggregation and more pronounced fragmentation. This implies that urban morphological complexity and the aggregation of carbon metabolism clusters are particularly critical indicators in low-carbon urban planning. Balancing these indicators to optimize the urban layout serves as a strategy to enhance urban low-carbon resilience.