The natural environment provides multiple ecosystem services for urban development and human quality of life. Given that current cities interact with each other and form urban agglomerations, understanding the spatiotemporal changes in ecosystem services and the driving forces is crucial for sustainable urban development. Using 12 national-level urban agglomerations as a case study, this paper quantifies the spatial patterns of multiple ecosystem service values from 2000 to 2015 and assesses how natural and socioeconomic factors contribute to such changes by using ordinary least squares (OLS) and geographically weighted regression (GWR). The results show the following: (1) spatial discrepancies of ecosystem services exist both in and between urban agglomerations, and ecosystem service values are reduced in more than 70% of urban agglomerations at a rate ranging from 0.02 to 4.27%; (2) elevation, precipitation, and fraction of woodland have positive impacts on ecosystem service values in urban agglomerations; while gross domestic product (GDP), population, and proportion of built-up area have negative effects; (3) both natural and social driving factors impact the ecosystem services of different urban agglomeration in different ways, according to the differences in their driving degrees. We categorized 12 urban agglomerations in China into six typical types: natural-factor dominated, socioeconomic-factor dominated, policy dominated, balanced, natural-factor inclined, and socioeconomic-factor inclined. Our results can be used to inform decision makers and urban planners to propose explicit location strategies to balance natural protection and socioeconomic development and ultimately promote sustainable urbanization across the nation.

Many empirical studies have shown evidence of multiple health benefits provided by green and blue spaces. Despite the importance of these spaces, investigations are scarce in details for blue spaces rather than green. Moreover, most research has focused on developed regions. A limited number of studies on blue spaces can be found in China with a focus on the city level. Outcomes have been mixed due to varying research scales, methodologies, and definitions. This study relies on a national-level social survey to explore how the self-rated health (SRH) of senior individuals is associated with local green and blue space availability in urban and rural areas. Results indicate that the coverage ratio of overall green spaces and waterbodies around a resident’s home have marginal effects on SRH status in both urban and rural areas. In urban areas, living close to a park can is marginally beneficial for older people’s health. Regarding different types of blue spaces, the presence of a major river (within 0.3–0.5 km) or coastline (within 1 km and 1–5 km) in the vicinity of home negatively affects SRH among the elderly in urban areas. Close proximity to lakes and other types of waterbodies with a water surface larger than 6.25 ha did not significantly influence SRH. These findings not only evaluate general health impacts of green/blue space development on senior populations across the county but inform decision makers concerning the health-promoting qualities and features of different green/blue spaces to better accommodate an aging population in the era of urbanization.

From the perspective of whole-area sponge city construction, it is important to scientifically determine the layout plan of LID facilities for controlling urban rainfall and flooding problems, given the topographical features and rainfall runoff characteristics of shallow urban mountainous areas. Current research on the optimization of low-impact development facilities is limited to the central urban area level, with insufficient research on shallow urban mountainous areas, and there is great uncertainty in the layout of LID facilities when multiple objectives are considered. Therefore, this paper applied a genetic algorithm (NSGA-II) to optimize the layout scheme of LID facilities. Multiple objectives of the peak runoff abatement rate, cost, and land area were selected as the optimization objectives, and the optimized results were ranked using the EWM-TOPSIS and VCWM-TOPSIS methods. The 2nd Hebei Provincial Garden Flower Expo (Qinhuangdao) Park was used as the research object for the optimization design. The results showed that, under the premise of water safety, the lowest cost priority was given to the LID facility with a 15.49% share, 99.43% peak runoff reduction rate, and a cost of CNY 1.215 × 10⁷; the lowest area priority was given to the LID facility with a 15.25% share, 99.42% peak runoff reduction rate, and a cost of CNY 1.267 × 10⁷. The EWM-TOPSIS method was also used to obtain the best optimized solution with 16.18% LID facilities, 99.64% peak runoff abatement rate, and a cost of CNY 1.26 × 10⁷, and the worst optimized solution with 12.55% LID facilities, 97.91% peak runoff abatement rate, and a cost of CNY 1.061 × 10⁷. The decision results under different decision-maker preferences were obtained by the VCWM-TOPSIS method. This study showed that the combination of a genetic algorithm and TOPSIS can optimize the layout of LID facilities in shallow mountainous areas more scientifically and efficiently compared to the actual construction plan for building a sponge city.

Urban greenspaces have been essential in supporting residents’ well-being during the COVID-19 pandemic, particularly under strict lockdown measures. However, the impact of changing containment policies on residents’ perceived greenspace quality remains insufficiently explored. This study utilized online survey data collected between 11 October and 29 December 2022, in Shanghai, coinciding with the major policy shift on 5 December 2022. A probability proportionate to size sampling was adopted to survey residents aged 18 and above who had lived in the city for at least six months, yielding a total of 577 valid responses. We assessed residents’ perceived greenspace quality using 20 park- and community-level variables, focusing on both overall quality and specific features of greenspaces. A regression discontinuity design (RDD) was applied to evaluate how the lifting of the COVID-19 policies influenced residents’ perceptions of parks and community greenspaces. Our RDD estimation indicates no statistically significant change in residents’ overall perceived quality of parks after the policy shift, except for increased satisfaction with specific features such as plant diversity, maintenance, seating areas, trails, and large open spaces. In contrast, residents who responded after the policy shift reported a significantly higher perceived quality of community greenspaces compared to those who completed the survey before the shift (0.609 score difference, p < 0.01), with notable increases in satisfaction regarding plant diversity, maintenance, and seating areas. Perception of plant quantity remained unchanged in both types of greenspaces. Residents expressed greater satisfaction with sports facilities in parks, while community greenspaces were preferred for their water features and esthetic qualities. By adopting an RDD with a unique dataset, this study contributes empirical evidence to the current ongoing debate on the role of urban greenspace during the later stages of COVID-19. Specifically, it examines how changes in public health policy and the resulting increase in mobility might affect residents’ perceived greenspace quality. The findings can assist decision-makers and urban planners in developing more adaptive strategies to address the diverse needs of residents for greenspaces during the transitional period of a public health crisis.