Optimizing two-step floating catchment area for green space accessibility and equity: Is mountainous green space more age friendly?

Green spaces provide leisure opportunities for older adults, who require high accessibility to such spaces. Improving the equity of green space accessibility will help support the attainment of Sustainable Development Goals. However, existing analyses of accessibility to green spaces have not considered the socioeconomic disadvantages of residential communities (disadvantages at the origin points) or the age-friendliness of the destinations, limiting their applicability for planning purposes. This study assessed age-friendly green space accessibility and equity among older residents by developing an optimized two-step floating catchment area model to quantify per capita green space availability. The results showed that only 17.06% of older adults have access to more than 5.5 m² of green space per person, and 45.17% cannot reach green space within 10 min. The average Gini index for the green space of the communities studied is 0.807. Accessibility and equity follow a central–peripheral disparities pattern, with a trade-off relationship among community disadvantage severity, accessibility, and equity. Mountainous green spaces pose greater barriers for older adults, underscoring the critical role of small community green spaces in meeting their needs. The age-friendly renewal of small mountainous green spaces should improve accessibility, amenities, and scenic aesthetics.