As a main place for student activities on campus, outdoor spaces have positive impacts on students’ physical and mental health. Namely, outdoor heat and comfort are of great significance to improve activity quality. Here, four unique outdoor spaces were studied to explore the varying effects on human thermal comfort during hot-summer and cold-winter periods. Distinct outdoor spaces (fully open, semi-open, semi-enclosed, and fully enclosed areas) from the southern campus of Anhui Jianzhu University were chosen. The PET was used as a metric for measuring thermal comfort and analyzing correlated spatiotemporal distributions. The results showed that outdoor thermal comfort was derived from multiple factors, including vegetation, underlying surface materials, building presence, and wind-heat environment. Notably, high correlations between Tmrt and thermal comfort were revealed, where such temperatures of places with trees or building shade were low; thus, PET was low. Further, Ws showed a significantly negative correlation with PET. Of the four outdoor space forms, the fully enclosed location had the lowest thermal comfort level, while the semi-enclosed spaces showed the highest level of body comfort. Therefore, semi-enclosed space (U-shaped) is recommended in campus planning and construction. Accordingly, an improved strategy was proposed based on experimental transformation for fully enclosed spaces. The thermal comfort after optimization was simulated to provide references for outdoor space thermal comfort improvement during seasonal extremes.

The thermal comfort of outdoor spaces in traditional villages must be improved because high building density combined with complex and narrow spaces leads to a poor thermal environment. In traditional villages, outdoor spaces are the most frequently used places by local residents and tourists. In this study, the Shimengao Village in Tangxi Town, Chizhou City, a typical mountainous area in the southern Anhui Province, was selected as the research object, and Depthmap software was used to identify the most frequently used outdoor spaces. The spatial layout and three different outdoor spaces of the traditional village were measured and validated using ENVI-met software. In addition, the distribution of thermal comfort in the core area of the village and influencing factors were analyzed. Our results demonstrated that during summer, PET reached its highest value at 15:00, exhibiting a poor thermal environment in the core area of traditional village integration. From 15:00 to 21:00, PET values declined, resulting in improved thermal comfort levels. Open spaces had better thermal comfort ratings throughout the day. The thermal comfort distribution of three different types of outdoor space in traditional villages was also analyzed. The courtyard space had the worst thermal comfort, followed by the street space, whereas the square space had the best thermal comfort environment. This was correlated with the spatial layout of traditional villages, external facilities of buildings, microlandscapes (plants, water availability, etc.), and outdoor ground materials. Hence, we propose that optimizing the overall spatial layout of a traditional village, increasing the external facilities of buildings, creating “micro landscapes,” and optimizing the materials of outdoor spaces are important for improving the thermal comfort of the outdoor spaces of traditional villages.

Urban densification associated with rapid urbanization has weakened horizontal ventilation in cities. Previous studies point out that building-height variability can enhance vertical ventilation, while most of them rely on idealized models that overlook the complexity of real urban environments. This study analyzes 20 actual urban blocks using CFD simulations, considering average building height, building density, and height standard deviation. The results show that areas with low-rise, uniform buildings exhibit superior pollutant dispersion, while mid- and high-rise zones experience complex turbulence and pollutant accumulation. Ventilation performance peaks when the height standard deviation ranges between 35 and 40. These findings underscore that optimizing urban form for vertical ventilation requires a combined strategy of density control and height variation. Realistic building group models more accurately capture airflow dynamics and provide valuable insights for the design of effective vertical ventilation corridors and the enhancement of urban pollutant dispersion.

The rapid development of new first-tier cities in China has led to potentially significant differences in residents’ environmental perceptions toward parks in new and old urban areas. However, there is currently a lack of relevant comparative research. Therefore, this study used the new first-tier city of Hefei as an example and selected the two most popular urban parks in the new and old downtown areas—Swan Lake Park and Xiaoyaojin Park. This study aimed to find out which aspects of the new and old city parks were the most valued by the residents by analysing their online comments on social media platforms. Based on the social media comments, quantitative and qualitative analyses were conducted to study residents’ perceptions and preferences and analyse residents’ activities and satisfaction. The research found the following: (1) There was consistency in the type of content in the downtown parks as perceived by the residents of the new and old urban areas. (2) For the old downtown Xiaoyaojin Park, the residents were more interested in the experience in terms of the recreation facilities and services but were less satisfied with the visitor capacity of the playground and the ticket price. For the new downtown Swan Lake Park, the residents were more interested in the experience in terms of the exercise facilities and venues and were worried about the safety of the venues. (3) The perceived environmental preferences of the residents in the old urban areas were mainly related to childhood activity venues, and the perceived environmental preferences of the residents in the new urban areas were mainly related to novelty activities. Based on the results, targeted suggestions were proposed for the development of characteristic resources, facility management and maintenance, and the renewal and renovation of recreational activities. Since social media analysis plays an important role in the construction of urban parks, the findings can help us to better understand residents’ lives, ensure that parks are designed for the happiness of the people, and develop more sustainable pathways for the design and management of urban areas.

Observations of energy and carbon dioxide fluxes in the urban centres of rapidly developing countries remain limited. In this study, one year of eddy covariance measurements was conducted in the city centre of Hefei to investigate how underlying urban surfaces and human activities influence surface energy and carbon dioxide fluxes. A strong correlation was observed between net radiation and sensible heat flux, with both fluxes being significantly lower in winter. Abundant summer precipitation substantially enhanced latent heat flux. Anthropogenic heat flux and storage heat flux ranged from 30 to 350 W m⁻² and from −100 to 350 W m⁻², respectively. Improved energy balance closure was generally associated with more unstable atmospheric conditions, while increased urban surface heterogeneity was linked to poorer closure. Traffic was identified as a major contributor to carbon dioxide emissions, with annual emissions reaching 12.73 kg CO₂ m⁻² yr⁻¹ in the city centre. Carbon dioxide fluxes were significantly higher in winter and slightly lower on weekends compared to weekdays. In addition, the increasing adoption of new energy vehicles (NEVs) has contributed to a reduction in urban CO₂ fluxes. Overall, human activity in urban centres substantially enhances anthropogenic heat release and carbon dioxide emissions, thereby intensifying urban heat island effects and carbon emissions.

As one of China’s “New Four Furnaces”, the city of Hangzhou faces significant heat challenges exacerbated by rapid urbanization. Urban parks offer effective nature-based solutions, but optimizing their multi-dimensional cooling performance—encompassing cooling area (PCA), efficiency (PCE), intensity (PCI), and gradient (PCG)—remains a key challenge. This study quantitatively analyzed the internal and external landscape features of 18 parks in Hangzhou, revealing that park cooling performance is not simply a case of “bigger is better.” We found that parks with more complex shapes and irregular boundaries exhibited higher cooling efficiency per unit area (PCE) compared to larger parks with smooth, simple shapes, though sometimes at the expense of peak PCI. Furthermore, the surrounding built environment is critical: high building density within a 300 m buffer zone was found to significantly impede the spatial extent of the cooling effect (PCA). Based on these findings, we propose that to effectively mitigate urban heat, cities should (1) shift focus away from creating large, isolated parks with smooth boundaries; (2) prioritize a network of smaller, morphologically diverse parks with irregular edges that extend into the community; and (3) enhance each park’s cooling reach through strategies like green streets and tree-lined paths. These approaches offer tangible, actionable guidance for designing high-performance cooling green infrastructure in dense urban environments.