From policy synergy to equitable greenspace: Unveiling the multifaceted effects of regional cooperation upon urban greenspace exposure inequality in China's megacity-regions

This study investigates the extent to which and how regional cooperation influences urban greenspace exposure inequality within China's megacity-regions. By employing a novel theoretical framework—the Greenspace Exposure Gini Index (GEGI)—which incorporates indicators of greenspace availability, proximity, and inequality, a case study of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) uncovers three key findings. First, greenspace exposure inequality has escalated in most GBA cities, with only Macao, Hong Kong, and Dongguan exhibiting a consistent decline. Post-2014, Guangzhou, Shenzhen, and Hong Kong have experienced a stabilization of greenspace exposure inequality, characterized by fluctuating but controlled levels. Second, regional cooperation has been found to mitigate greenspace exposure inequality through strategic resource allocation and infrastructure investment. Nonetheless, the effectiveness of such cooperation is contingent upon addressing the complexities of regional spatial heterogeneity and non-stationarity. Last, the analysis unveils a potential unintended consequence of economic, social, and institutional cooperation within the region: the exacerbation of greenspace exposure inequality. This phenomenon arises when resource allocation disproportionately favors economically developed areas, thereby widening disparities in greenspace access. In conclusion, this study illuminates the evolving nature of regional cooperation, shifting from a primary focus on policy alignment and resource synergy to a more nuanced approach aimed at reducing urban greenspace exposure inequality.