Evaluation and Promotion of the Service Capacity of Urban Public Open Spaces Based on Improving Accessibility: A Case Study of Shenyang City, China

The service capacity of urban public open spaces is an important indicator of the justness and soundness of the allocation of public space resources, such as parks and green spaces, in the process of urban development. Improving the service capacity of urban public open spaces is conductive to healthy, sustainable urban development. In this study, taking Shengyang City, China as a case study, a Gaussian-based two-step floating catchment area method (2SFCA) is used to calculate an accessibility index and identify residential areas with a poor accessibility to urban public open spaces. Then, a particle swarm algorithm (PSA) is used to optimize the locations of new open space developments. Finally, the optimization results are verified using the analytic network process (ANP). The results show that the service capacity of public open spaces in the center of Shenyang City (covering six districts) is relatively low and exhibits an uneven spatial distribution. In the service scope of the existing urban public open spaces, the accessibility for 48.6% of the residential estates is moderately poor or poor. The layout is optimized when the number of optimization points is set to 8. These points are mainly located in old town areas such as the Tiexi, Huanggu, and Dadong districts. The optimization increases the green space area accessible by motor vehicles (60 min), bicycles (60 min), and walking (30 min) by 4.67%, 5.38%, and 8.03% of the study area, respectively. Finally, green space planning recommendations are offered from two perspectives: spatial layout and transport system optimization.