Extensive inequality of residential greenspace exposure within urban areas in China

Ensuring residents' equal access to high quality urban greenspace is vital for urban environmental justice and sustainable urban development. However, most previous studies have mainly focused on greenspace quantity, overlooking its quality. Moreover, the national-level spatial distribution pattern of residential greenspace exposure (RGE) within urban areas remains unclear. Here, we have improved the existing RGE assessment framework by integrating both the quality and quantity of urban greenspace to evaluate RGE and its associated inequality across 119,692 blocks in 334 Chinese cities in 2020. We find that the spatial distribution pattern of RGE varies with urban size. Large cities exhibit a distinct clustering of low RGE in their central areas, whereas small cities tend to show a pronounced clustering of high RGE in the central areas. RGE in Chinese cities indicates extensive inequality, as the average RGE of high-exposed people is nearly four times greater than that of low-exposed people. Moreover, residents in larger cities are more prone to experiencing greater inequalities compared to those in smaller cities. We also find that the landscape metrics (i.e., connectance index and mean Euclidean nearest-neighbor distance) of greenspace possess a strong explanatory power (R² = 0.431) for the observed inequality. Our study underscores the importance of optimizing the landscape structure of urban greenspace and enhancing equality in the quality of greenspace. These findings provide novel insights for urban greenspace planning and promoting urban environmental justice.