【目的】社区生活圈是居民日常生活接触最密切的空间单元。评估生活圈内公园绿地的暴露水平,能够精准刻画居民与公共绿色资源日常交互场景,识别公园绿地服务盲点。【方法】选取南京市中心城区为实证案例,首先通过Isochrone 应用程序编程接口(API)计算居住小区15 min步行等时圈,以此作为社区生活圈的划定依据;其次构建了一个涵盖数量、面积、距离和质量的系统性暴露水平测度体系来评估圈内公园绿地暴露度;最后,采用区位熵指数和Getis-Ord {G_{\mathrm{i}}}^{\mathrm{*}}指数分析公园绿地暴露度和人口之间的供需空间匹配度,以及公园绿地暴露冷点-热点居住小区的空间聚类分布。【结果】①南京城区居住小区的公园绿地暴露度存在空间分布不均衡性,城区内近一半的居住小区分布在公园绿地暴露的盲点(20.12%)和冷点(25.63%)区域;②区位熵指数表明研究区域内公园绿地暴露度与人口之间的空间匹配度失衡;③公园绿地暴露度呈现了显著的“圈层”结构聚类状态。【结论】研究成果可为细化城市绿地系统规划、促进公园绿地科学合理的配置提供理论和实践支撑。

【Objective】The community life circle is the most basic spatial unit comprising residents’ daily lives. Assessing exposure to park green spaces (PGSs) within the community life circle can accurately portray daily interactions between urban residents and public green resources, thus identifying blind spots in PGS services. 【Methed】In this study, we selected the central area of Nanjing city as a case study. First, the 15-minute walkable zone of the residential community was calculated using the isochrone as the basis for the demarcation of the community life circle. Additionally, a systematic exposure assessment framework covering quantity, area, distance and quality was constructed to assess the service capacity of PGSs within the walkable zone. Finally, the locational entropy and Getis-Ord G_{\mathrm{i}}^{\mathrm{*}} indexes were used to analyze the spatial match of supply and demand between PGS exposure and demand from residents, in addition to the spatial clustering distribution of PGS exposure within cold-hot spot communities. 【Result】(1) An uneven spatial distribution of PGS exposure existed within urban residential areas, with 20.12% and 25.63% of the residential communities being located in the blind and cold spots, respectively. (2) The locational entropy index indicated that there was an imbalance within the spatial matching between PGS exposure and urban dwellers’ demand. (3) The PGS exposure showed a significant “circle” structure clustering. 【Conclusion】These findings provide theoretical support for refining the planning of urban green space systems while also promoting the scientific and reasonable allocation of PGS.