Temporal Changes in Green Infrastructure and Heat Risk Inequality across cities of Northern Taiwan

Green infrastructure serves as essential sources of natural cooling and social interaction, critical for city dwellers in mitigating heat risk under global warming. Their distribution is influenced by natural environments and urbanization stages, which often correlate with socioeconomic features, leading to inequalities in heat adaptation. This study provides a dynamic perspective by analyzing temporal changes in temperature anomalies, green space patterns, and social vulnerability to heat. Using six urban agglomerations at different urbanization stages in Northern Taiwan as case studies, this study evaluated how urban development has shaped the relationship between green spaces and heat risk between 2009-2012 and 2019-2022 periods, focusing on the changing patterns of cooling and social provisions from green spaces.

Results reveal distinct geographical variations in warming patterns, social vulnerability, and heat risk. While less fragmented green spaces contributed to lower temperatures, increases in green spaces did not necessarily reduce warming. In major cities, populations highly vulnerable to heat stress had better access to the cooling benefits of green spaces. In most cities, green spaces available for social interaction were more available in areas with higher vulnerable populations during 2009-2012, while this relationship has weakened in recent years. Spatial analysis revealed clustering patterns between changes in green spaces and heat risk. Within Taipei Basin, green spaces tended to increase in the city center with either rising or declining heat risk, while decreasing in peri-urban areas with rising risk over the study period. This temporal assessment of heat risk inequality provides insights for decision makers, suggesting that nature-based solutions through strategic green space planning must not neglect constant negative impacts from further urbanization, different warming intensity, and social vulnerability changes over time, instead of viewing nature-based solutions as a panacea.