Assessment and optimization of spatial equity for urban parks: A case study in Nanjing, China

Equitable access to parks, in alignment with resident needs, is crucial for promoting social equity, justice, and sustainable urban development. However, existing methodologies for evaluating park accessibility often overlook the effect of park popularity and resident choices. To address this limitation, this study introduces an improved two-step floating catchment area (2SFCA) method. This enhanced approach incorporates real-time user data to measure park popularity and employs the Huff model to determine the probability of residents selecting a specific park. By integrating these factors, the study offers a more accurate and robust assessment of park accessibility for residents in Jiangnan Main City, a central district in Nanjing's urban core. The study utilizes the Gini index and Lorenz curve to appraise the demographic equity of park distribution in the study area. In addition, bivariate spatial autocorrelation analysis is employed to analyze the spatial patterns of park supply and demand. The findings indicate a spatial trend characterized by high accessibility in central locations and reduced accessibility in peripheral areas. Additionally, the northern section exhibits greater accessibility compared to the southern part. The calculated Gini index indicates that the top 10% of the population enjoys access to nearly 36% of the parks, highlighting a significant imbalance. In addition, a spatial mismatch is evident, with significant dislocation between parks and residential areas observed in approximately 29% of residential communities. Simulations conducted in the study demonstrate a marginal improvement in park spatial equity when accounting for park popularity and resident choice. These results emphasize the importance of incorporating these factors in park planning and management strategies. The study advocates for park planning that prioritizes equity and a balance between supply and demand. Moreover, it emphasizes the need for tailored strategies that cater to the unique characteristics of different urban areas.