Will the opening community policy improve the equity of green accessibility and in what ways? — Response based on a 2-step floating catchment area method and genetic algorithm

Abstract Green space within residential areas is an important part of urban green space. However, in the past, these areas have not been completely open to the public and are only available to residents of the community within gated fences. At present, China has proposed to gradually open these closed communities, but quantitative assessment of the impacts of implementation on equity of green accessibility has not been explored. This paper selected Wuhan as a research case and used a Gaussian-based two-step floating catchment (2SFCA) and genetic algorithm to analyze and simulate whether the opened community policy would improve the equity of green accessibility, and how to best implement it. The main conclusions were: 1) The average green accessibility of the community within 1 km, 2.5 km, 5 km, and 10 km increased from 76.08, 75.50, 85.01, and 64.28 in the closed state to 102.43, 103.83, 114.39, and 94.87 in the fully open state; 2) After opening the gates, green equity was lower than before within the 1 km and 2.5 km thresholds, while opening the gates at distance thresholds over 3.6 km, green equity was promoted; 3) After optimization by the genetic algorithm, Gini coefficients for green equity were 0.39 and 0.28 within the 1 km and 2.5 km thresholds, and equity clearly increased compared to full community closure or full opening. This study quantified the spatial relationship between residents and green space and can be used to improve equitable spatial allocation of urban green space.