Analysis of the impact of opening and sharing of affiliated green spaces on the accessibility and equal access of green spaces: a case study in Shanghai

Within the context of limited land resources in densely populated urban areas, the opening and sharing of affiliated green spaces have become an innovative way to expand urban green spaces. The research objects of this study were university and industrial park-affiliated green spaces in Shanghai. This study identified the total area and distribution of these green spaces using the extraction and analysis of remote sensing image data, current image data for affiliated green spaces, and census data. Based on these data, this study simulated and analyzes the changes and spatial differentiation in the accessibility and equity of green spaces in different districts, such as the central city, the Pudong New Area, and the suburbs. This study examined three scenarios: open and shared university-affiliated green spaces, industrial park-affiliated green spaces, and the two combined. The results show that the overall area of affiliated green spaces (excluding residential areas) is large, with small individual patch areas, a wide distribution, and high frag-mentation. University- and industrial park-affiliated green spaces account for nearly one-third of the total area and have great potential for open sharing. In the simulation of open sharing, the accessibility of green spaces generally improved, and there were different effects depending on the location and time. University-affiliated green spaces mainly improved the central urban area, focusing on short-distance walking accessibility. Industrial park-affiliated green spaces mainly improved the suburbs, focusing on long-distance walking accessibility. Overall, the opening and sharing of university-affiliated green spaces only improve the evenness of green spaces in the central urban area, while industrial park-affiliated green spaces improve the evenness throughout Shanghai. The combined effect of both types significantly enhances the evenness of park green spaces throughout Shanghai. Therefore, the opening and sharing of university- and industrial park-affiliated green spaces should be an important means to increase the amount of green spaces in high-density areas. These conclusions provide scientific data that support future policies in Shanghai.