Public open space (POS) confers numerous physical and mental health benefits to people throughout life. The study applies POI and other multi-dimensional methods to examine the intergenerational equity of POS within a 15-min living circle of old communities in high-density cities. Firstly, an evaluation system for the comprehensive POS supply level in the community is constructed from the perspective of the quantity, quality, and spatial distribution of POS. Secondly, based on the idea of all-age sharing, the population in the community is divided into children, young and middle-aged, and elderly, and the factor “adaptation space share” is introduced to supplement the intergenerational equity evaluation system. The study takes Caoyang New Village in Shanghai as an example and the districts of the community committee as the basic evaluation units. The results show that the comprehensive supply of POS in Caoyang New Village is relatively high but there is still a mismatch between supply and demand; the intergenerational equity level is medium, and spatial alienation exists between POS supply and intergenerational equity; and the adaptation space share for children is much higher than that for the elderly, young and middle-aged people. Furthermore, young and middle-aged people are found to form a marginal group in spatial sharing and resource allocation. Finally, it is proposed that in community POS planning, attention should be focused on the differences in population age structure and on spatial cultural attributes and functional compounding on the basis of ensuring the comprehensive service of POS, so as to promote all-age sharing in community POS.

With the continuous expansion of urban construction land, the green belts aiming for ecological protection have ensured a sustainable and effective function of regional ecosystem services. At the same time, these ecological green belts are expected to develop their compound service potentials with the development of cities. In order to meet the increasing demand of urban residents for the recreational utilization of urban green space, the primary function of the ecological green belts has transformed from being purely ecological to a combination of being ecological and recreational. Based on social media data, which has the characteristics of a large amount of accessible geographic information, this study used multiple regression models to analyze the recreational utilization intensity of ecological protection green belts with a case study in the green belt of Shanghai, China. The research results showed that the internal elements (total external area, water area, etc.) of the Shanghai green belt have positive correlations with its recreational utilization. The impact of external factors was inconclusive on the recreational utilization of the outer forest belt (the number of subway stations in accessibility factors was negatively correlated; the number of cultural facilities and the number of restaurants in the surrounding service facilities were positively related). Combined with the “Shanghai City Master Plan (2017–2035)”, this study suggests potential zones for the recreational transformation of the Shanghai green belt, provides a theoretical and practical basis for improving the recreational utilization of an urban ecological protection green belt and contributes to the sustainable development of ecological protection green belts in high-density cities.

Urban blue spaces (UBSs) hold significant value in terms of public health, tourism economy, and residents’ well-being. The Huangpu River in Shanghai, renowned as a global urban blue space, currently faces challenges such as unequal service capacity across sections and varying levels of spatial vitality. This study incorporates the concept of “service effectiveness” into public space evaluation. Drawing inspiration from the 4E (economics, efficiency, equity, and effectiveness) principles of effectiveness evaluation, a social service effectiveness evaluation system is constructed to measure service efficiency and effect. Through the literature research, 6 primary indicators and 12 secondary indicators are set to investigate the utilization rate and realization effect of the UBS. The evaluation system utilizes field surveys, text analysis, and remote-sensing techniques to collect relevant data. Through standardized calculations, different aspects of the indicators are integrated into a single evaluation criterion. The “overall effectiveness index” and the “efficiency–effect balance index” is introduced to quantitatively analyze the overall effectiveness characteristics, including spatial characteristics and time-varying characteristics, as well as efficiency–effect balance and imbalances. The evaluation located three low-effectiveness sections and three imbalanced sections at the north and south ends of the core section of the Huangpu River. The influence factors of effectiveness are analyzed through correlation test and literature studies, mainly including the urban hinterland, service facilities, environmental quality, and management publicity factors. This study aims to provide research ideas and methods for waterfront area planning and city-refined management.