Summertime physiological and thermal responses among activity levels in campus outdoor spaces in a humid subtropical city

Comparative analysis of visual-thermal perceptions and emotional responses in outdoor open spaces: Impacts of look-up vs. look-forward viewing perspectives

Horizontal and vertical viewing perspectives exert varying influences on the environmental perceptions and emotional states of college students. Despite this, scant research addresses the impact on this demographic. We selected typical campus open spaces for comprehensive physical parameter assessments, encompassing meteorological and spatial characteristics. A cohort of 36 healthy college students participated in a questionnaire survey designed to ascertain shifts in visual comfort, thermal comfort, and emotional responses when viewing landscapes in look-forward and look-up orientations. Key findings following both viewing modalities included: 1) a notable rise in mean visual comfort vote (MVCV), by 1.22 for look-forward and 1.01 for look-up, with a pronouncedly higher sunlight sensation vote (SSV) for the latter orientation; 2) a significant increase in thermal comfort vote (TCV), although the difference in increments between the two viewing angles was minimal; 3) Positive affect (PA) exhibited considerable improvement in both viewing conditions, while negative affect (NA) was markedly reduced in the look-up condition relative to look-forward viewing; 4) The SSV was predominantly influenced by the trunk ratio and canopy-to-trunk ratio, with substantial weights of 31.47% and 32.15%, respectively. Landscape element diversity emerged as the most critical factor affecting visual comfort vote (VCV) and aesthetic assessment score (AAS), with overwhelming weights of 70.67% and 63.15%, respectively. Moreover, the leaf ratio was identified as the chief determinant of emotional responses. Our results provide insights into the design of campus spaces for enhanced student well-being.

How outdoor horticultural activities affect elderly adults' thermal, physiological and psychological responses: a field study

We recruited 162 healthy elderly adults to determine the thermal, physiological, and psychological effects of horticultural activities (flower arranging, transplanting, and rubble masonry) in outdoor open spaces. We linked these to local climate conditions, physiology, and comfort through a questionnaire survey. The results showed that: (1) the neutral physiological equivalent temperature (NPET) before the horticultural activities were 22.18 ℃ for flower arranging, 23.67 ℃ for transplanting, and 20.78 ℃ for rubble masonry, while the NPET decreased to 18.53 ℃, 20.73 ℃ and 18.04 ℃ (respectively) after activities. (2) The heart rate and blood oxygen saturation changed significantly (p < 0.05) only after rubble masonry. (3) The average positive affect (PA) scores increased after flower arranging by 4.83, transplanting by 3.30, and rubble masonry by 4.00. (4) After activities, the thermal sensation vote was mainly influenced by globe temperature (41.36%), air temperature (33.47%), and wind speed (25.17%). Thermal comfort vote could be promoted because of 37.35% of an increasing positive and 21.20% of decreasing negative emotion.

Investigating the impact of a large river and its surrounding contextual conditions on pedestrians' summer thermal perceptions in a Cfa-climate city

Thermal comfort studies are usually employed to find subjective thermal responses [indicated by neutral temperature (NT), i.e. the temperature with no thermal stress] of residents from a region towards thermal environments. According to the recently published works in the literature, NTs are affected by many factors, such as geographical location and microenvironments. To elucidate the origins of these effects, the impact of microenvironment elements around a water surface on pedestrians' thermal perceptions was systematically investigated in this work. The Fujiang River (FJR) in Mianyang City was taken as the sample site. The municipal meteorology station is located next to the site by around 2.5 km. By performing meteorology measurements combining questionnaires, it was found that the riverside NT (indicated by physiologically equivalent temperature, PET) of Mianyang in the summer of 2023 was 21.4 °C. The relationship between the distance from the water (DFW) and NT was quadratic linear. The same phenomenon took place by using either PET or Universal Thermal Climate Index (UTCI) indexes. Meanwhile, the meteorological contexts also affected NTs, including relative humidity (RH) and air velocity (Va). Regarding RH, the NPET increased from 15.2 °C (RH = 50%) to 26.9 °C (RH = 90%). In contrast, the NPET dropped from 23.0 to - 50.6 °C when the Va increased from 0.2 to 2.5 m/s, respectively. From our analysis, it was demonstrated that human thermal responses are significantly affected by both the microenvironmental and meteorological backgrounds around the water surface. Our work provides valuable insights for the proper use of water surfaces in urban design for adjusting thermal comfort.

The effects of brightness and prominent colors on outdoor thermal perception in Chongqing, China

Outdoor thermal comfort has become an important factor affecting human mental and physical health due to rapid urbanization. This study aimed to investigate the influence of brightness and prominent colors on thermal perception in hot summer and cold winter regions. Meteorological measurements were conducted accompanied by subjective thermal and visual questionnaires (n = 2020) during summer and winter. The physiological equivalent temperature (PET) was applied as thermal indices to evaluate the influence of visual conditions on thermal perception. The results showed that (1) the neutral PET is 20.2 °C with a range of 14.8 ~ 25.7 °C in Chongqing and neutral illumination range is 0 ~ 8663 lx. (2) Thermal sensitivity is most great in neutral brightness than bright and too bright groups. The influence of outdoor prominent colors in winter supports hue-heat hypothesis. However, in summer, result only supports the hypothesis under low thermal stress. Both cool and warm colors can reduce the thermal sensitivity of visitors compared to neutral colors (gray and white). (3) The interactions between colors and brightness are more obvious under low thermal stress levels. (4) Thermal perceptions of females are more greatly affected by brightness and prominent colors compared with males. These results could help landscape designers better understand the correlation between the thermal and visual environments and provide a reference for comprehensive designs of urban open spaces.

A study of acoustic-light-thermal effects on pedestrians' overall comfort in a Cfa-climate campus during the summer

The environmental quality, in terms of acoustic, visual, and thermal environments, significantly affects people's comfort levels. Along these lines, in this work, their comprehensive impact on people's overall comfort was systematically explored. Pedestrians' outdoor neutral points on various environmental parameters were found by performing linear regressions. Similarly, people's thermal perceptions (indicated by neutral temperatures, NT) were found to vary for both acoustic and light environments. They would be increasingly heat sensitive (R2 increases) in a noisier environment while the NTs varied for either sound or light intensity levels. From our analysis, it was demonstrated that people's overall comforts were negatively correlated with these parameters in different degrees. This work provides valuable insights for future urban design and planning studies to create better outdoor environments.

Study on the outdoor thermal comfort of college students under different activity intensities in a high-altitude climate zone

Introduction

Research on the outdoor thermal comfort (OTC) of a university campus is beneficial to the physical and mental health of college students.

Methods

In this study, the OTC of students attending Tibet University in Lhasa, which experiences high-altitude cold climate conditions, under different activity intensities was studied using field measurements and a questionnaire survey.

Results

With the increase in activity intensity, the comfort physiologically equivalent temperature (PET) value gradually increased in summer, while the comfortable PET value gradually decreased in winter. The most comfortable PET value is 17.6°C in summer and 11.5°C in winter. The neutral PET of Tibetan college students during outdoor activities in summer was 16.3°C, and the neutral PET of outdoor activities in winter was 12.1°C. Gender and ethnicity had different effects on thermal sensation under different activity intensities. Under vigorous-intensity activities, PET in winter and summer had the greatest influence on thermal sensation. The situation was different under moderate-intensity activity. PET had the greatest influence on thermal sensation in summer, and Tmrt had the greatest influence on thermal sensation in winter.

Discussion

These findings provide a basis for an improved design of the outdoor environment under different outdoor activity intensities in high-altitude areas.

Exploring the association between campus environment of higher education and student health: A systematic review of findings and measures

Numerous studies have investigated the relationship between the neighborhood environments and residents' health. However, other important settings, such as university campuses, have received little attention. This paper conducted a systematic review and synthesized existing empirical works examining the association between the university/college campuses built and natural environments and students' health. Following the PRISMA guidelines, we searched nine databases using keywords related to higher-education campuses and health-related outcomes. A total of 19 articles were identified, including fifteen cross-sectional studies, three experimental studies, and one longitudinal study. The majority of the studies were conducted in Asian countries and published in the past five years. The findings indicate that active transportation infrastructure, such as increased road intersections and better walkability, were found to be positively associated with students' physical activity. The natural environments, including perceived naturalness, blue space, and greenness was shown to support student's mental health and quality of life. Specifically, blue space was found to be the most preferred place for mental restoration, and scattered trees demonstrated a supportive effect in reducing depression symptoms. Even just viewing virtual trees had a restorative effect and feel less anxiety. Additionally, during the summer, tree shadows were identified as the most important factors for enhancing thermal comfort. This review emphasizes the crucial role of campus environments in promoting college students' health. Future longitudinal studies and investigations using multiple campuses would provide a more comprehensive understanding of this relationship. Such endeavors can contribute to the development of evidence-based strategies for designing and planning healthy campus environments that optimize students' well-being.

Using geospatial trajectories to explore how the COVID-19 pandemic affects the associations between environmental attributes and runnability of park trails

The worldwide coronavirus disease 2019 (COVID-19) pandemic and the associated social distancing measures have produced alterations in park visits of individuals, as well as their park-based physical activity (e.g. running exercise). Although studies on the influence of the COVID-19 pandemic on changes in running activity patterns are becoming an emerging focus, less is known about how these changes are related to the environmental attributes of parks before and after the pandemic, the knowledge of which is essential to planning green infrastructure that better supports physical activities. Therefore, we employed a volunteered geographic information approach to investigate the runnability of park trails in Shenzhen, utilizing self-tracking routes from Strava, in order to uncover the associations between trail characteristics and park features with the running intensity before and after the pandemic. Multilevel regression model analyses revealed that trail network connectivity was the only environmental attribute indicating consistent and positive associations with running intensity. Blue space density was positively correlated with running intensity in urban parks but indicated no significant association in forest parks before the pandemic. In the pre-pandemic era, population density was positively related to running intensity in urban and forest parks. However, after the pandemic, the associations between running behaviours and population density remained positive in forest parks but turned insignificant in urban parks. The outbreak of the pandemic also altered the influence of other park features (e.g. park shape and trail density) on running intensity. The evidence-based knowledge provides planners with significant insights into pandemic-resilient park planning for the post-COVID era.

Experimental investigation of the effect of surgical masks on outdoor thermal comfort in Xiamen, China

The COVID-19 pandemic has significantly changed people's lifestyles, and wearing surgical masks in outdoor public spaces has become commonplace. However, few studies have explored the impact of wearing masks on outdoor thermal comfort in different seasons. From May 2021 to February 2022, a series of longitudinal experiments were conducted in Xiamen, China to examine the effect of wearing surgical masks on outdoor thermal comfort. Forty-two participants took part in the experiments with and without masks. During the experiments, the thermal perceptions of the subjects and environmental thermal parameters were collected. Differences in outdoor thermal comfort between subjects wearing masks and those not wearing masks were determined in summer, autumn, and winter. Results showed that 1) the subjects wearing masks had lower neutral temperatures, and this difference was particularly pronounced in summer and exacerbated by walking; 2) in warm environments, masks reduced thermal comfort, and discomfort associated with masks was worse when walking than when sitting; 3) wearing masks significantly worsened facial comfort and increased chest discomfort, as summer turned to winter, the impact of masks on facial comfort decreased; 4) radiation and air temperature were the environmental parameters with the greatest impact on outdoor thermal sensation. Subjects who wore masks preferred lower temperatures, radiation, and humidity, and higher wind speeds.

Spatial differences in thermal comfort in summer in coastal areas: A study on Dalian, China

Thermal comfort is an important indicator for evaluating the environment of urban public space, and appropriate thermal comfort can effectively prolong the duration of outdoor activities. In the existing studies, there is a lack of thermal comfort comparison between hot spots and cold spots. In this study, we selected the coastal city of Dalian in China as our study area and conducted field investigations on the thermal comfort of two landmark resorts, namely, a downtown commercial street and coastal leisure park. The study was conducted on typical summer days and consisted of interviewing several residents to understand their thermal comfort requirements. We investigated the thermal expectations of the interviewees through meteorological measurements and questionnaires. The universal thermal climate index (UTCI) was used to determine the thermal benchmarks of the on-site subjects. The results indicated that (1) globe temperature and air temperature were the most important factors that affected thermal comfort, followed by relative humidity and wind speed in summer daytime. (2) Shaded spaces are more comfortable than open spaces, and tree shade is preferred over artificial shade in coastal park. (3) The neutral UTCI (NUTCI) of the respondents were 24.1°C (coastal park) and 26.0°C (commercial street); the neutral UTCI ranges (NUTCIR) were 20.8-27.4°C (coastal park) and 23.3-28.7°C (commercial street). (4) The upper thermal acceptable range limits of the coastal park and commercial street were 30.2 and 32.1°C, respectively, which were substantially higher than the upper NUTCIR limit, indicating that the residents in Dalian were well-adapted to hot weather. The results can provide a good reference for determining ideal design strategies to optimize the thermal environment of urban outdoor recreation spaces in summers and improve the quality of life in coastal cities.

Multi-domain human-oriented approach to evaluate human comfort in outdoor environments

Human comfort outdoors is widely investigated, but most studies explore the comfort domains singularly. This paper aimed to evaluate human comfort in parks, verifying the importance of using a multi-domain (simultaneously evaluating thermal, visual, acoustic, and air quality) and multi-disciplinary (combining environmental and social fields) approach. A walk through a pre-defined path from one park to another was repeated twice per day on four consecutive days in June, with three participants per walk. The two investigated parks are in central Italy and were chosen because they differ in their design and spatial characteristics. Environmental data were recorded with an innovative wearable device during the whole walk, and surveys were used to assess people's perceptions of the parks. Despite observed differences in collected physical parameters, the survey's responses were similar, and different comfort domains showed dependence on each other in the two parks. Logistic regression models were developed for each park, and they revealed that the qualitative information predicted the overall comfort level more accurately than the environmental data. In detail, the models based on environmental data resulted in R² equal to 0.126 and 0.111 in Parks 1 and 2, respectively, whereas using the survey answers increased it up to 0.820 (Park 1) and 0.806 (Park 2). This study contributes to addressing the gap in multi-domain comfort studies outdoors and confirms the importance of using multi-disciplinary and multi-domain approaches for a complete comfort analysis, supporting holistic human-biometeorology-oriented models and forecasting opportunities that can promote improvements in urban environmental quality and liveability.

Effects of tree plantings and aspect ratios on pedestrian visual and thermal comfort using scaled outdoor experiments

Urban trees ameliorate heat stress for urban dwellers. However, it is difficult to quantitatively assess the integrated impacts of tree planting and street layouts on visual and thermal comfort in simulations and urban field experiments. We conducted scaled outdoor experiments in Guangzhou to investigate the influence of tree plantings on pedestrian visual and thermal comfort in street canyons with various aspect ratios (H/W = 1, 2, 3; H = 1.2 m). We considered the effects of tree crown covers (big and small crown) and tree planting densities (ρ = 1, 0.5) on pedestrian illuminance level and two thermal comfort indices (Physiological Equivalent Temperature: PET and Index of Thermal Stress: ITS). When ρ = 1, trees in most cases reduce pedestrian illuminance (maximum 140.0klux) and improve visual comfort. Decreasing ρ from 1 to 0.5 increases the illuminance (maximum 179.5klux) in the streets with big crown trees (H/W = 1, 2) and in the street with small crown trees (H/W = 2). When ρ = 1 (H/W = 1, 2), big crown trees decrease the peak daytime PET (by about 4.0 °C) and ITS (by about 285 W). Small crown trees (ρ = 1, H/W = 1, 2) produce a warming effect on peak daytime PET (2.0-3.0 °C), but a reduction in ITS is observed when H/W = 2, 3. After reducing ρ from 1 to 0.5, big crown trees increase peak daytime thermal stress according to both indices when H/W = 1, 2. Small crown trees exhibit a similar PET cycle between ρ = 0.5 and ρ = 1 across various H/W, but their daytime reduction of ITS is less effective when ρ = 0.5 (H/W = 2). The discrepancies between PET and ITS are attributed to their different approaches to modelling radiation fluxes. The narrower the street, the lower the illuminance, PET, and ITS, while their increases caused by reduced ρ are limited in narrow streets. Our study informs some potential urban tree planting strategies and produces high-quality validation data for numerical simulations and theoretical models.

How to design comfortable open spaces for the elderly? Implications of their thermal perceptions in an urban park

Elderly residents are prominent users of urban parks and comfortable open spaces in parks have been shown to improve their physical health and mental well-being. In this study, the thermal perceptions (thermal sensation, thermal comfort and thermal acceptability) of elderly visitors to an urban park in Xi'an, China was investigated using meteorological measurements, questionnaire surveys and activity records. Physiological equivalent temperature (PET) was used to determine thermal benchmarks. Spatial-temporal distributions of the elderly in open spaces were recorded and relationships among elderly residents' thermal perceptions, their age and chronic disease were analyzed. Finally, optimal design strategies for open spaces suitable for the elderly were proposed based on meteorological characteristics, elderly residents' attendance patterns and their thermal perceptions. Results showed that: 1) globe temperature (T_g) and air temperature (T_a) were the primary meteorological factors that influenced elderly residents' thermal sensation while clothing insulation and activity intensity were negatively correlated with their thermal sensation. 2) Attendance was significantly affected by the outdoor microclimate, space functionality and facilities in spaces. The elderly mainly participated in dynamic activities and social interaction. 3) The neutral PET (NPET) was 13.2 °C, with NPET range (NPETR) of 3.1-23.2 °C. The 90% thermal acceptable PET ranged between 10.9 and 25.9 °C, and the preferred PET was 14.4 °C. Compared with the ISO7730 standard, the predicted percentage of dissatisfied (PPD) elderly park users was lower than users of indoor spaces when -1 ≤ MTSV ≤ + 1, indicating that the elderly preferred to conduct activities outside when the environment was comfortable. Additionally, NPET for the elderly with respiratory disease was higher than those with cardiovascular diseases and diabetes. 4) Optimal design strategies for open spaces were proposed for elderly residents based on their physical, physiological and psychological preferences.

Interactive effect between long-term and short-term thermal history on outdoor thermal comfort: Comparison between Guangzhou, Zhuhai and Melbourne

Thermal history can influence human thermal comfort through physiological (short-term) and psychological (long-term) aspects. However, the nature of the interaction between long-term and short-term thermal history is unclear. To investigate the interactive effects of long-term and short-term thermal history on outdoor thermal comfort, we conducted summer thermal comfort surveys in Melbourne (n = 3293, January-February 2014), Guangzhou, and Zhuhai (n = 4304, September 2018). The mean thermal sensation of residents of Guangzhou was higher than that of Melbourne and Zhuhai residents under a similar Universal Thermal Climate Index (UTCI) range. The preferred UTCI was the highest for Melbourne residents (19.62 °C). When UTCI was 25.6-38.4 °C, respondents' mean thermal sensation from Köppen climate zones A, B, and C was significantly higher in Guangzhou than those of Zhuhai and Melbourne. A three-way ANOVA test revealed that peoples' thermal sensations depended on a significant interaction among UTCI thermal stress levels, climate zones, and prior exposure environment. The prior exposure environment could affect the difference in thermal perception between climate zones. However, there was no significant interaction between climate zones and activity engaged in before taking the survey on thermal sensation. The difference in the thermal perception of various climate zones diminished under universally uncomfortable conditions for specific prior exposure environments and activities. The socio-ecological system model, environmental perception theory, climatocultural adaptation, and alliesthesia are useful for understanding the interactive effect of long- and short-term thermal history on outdoor thermal comfort. By revealing how people adapt to different climatic environments, our results can help ensure that people with diverse climatic backgrounds can experience thermal comfort outdoors.

Comparative Study on the Cooling Effects of Green Space Patterns in Waterfront Build-Up Blocks: An Experience from Shanghai

Different structural patterns of waterfront green space networks in built-up areas have different synergistic cooling characteristics in cities. This study’s aim is to determine what kinds of spatial structures and morphologies of waterfront green spaces offer a good cooling effect, combined with three different typical patterns in Shanghai. A multidimensional spatial influence variable system based on the cooling effect was constructed to describe the spatial structural and morphological factors of the green space network. The ENVI-met 4.3 software, developed by Michael Bruse at Bochum, German, was used to simulate the microclimate distribution data, combined with the boosted regression tree (BRT) model and the correlation analysis method. The results showed that at the network level, the distance from the water body and the connectivity of green space had a stronger cooling correlation. The orientation of green corridors consistent with a summer monsoon had larger cooling effect ranges. In terms of spatial morphology, the vegetation sky view factor (SVF) and Vegetation Surface Albedo (VS_Albedo) had an important correlation with air temperature (T), and the green corridor with a 20–25 m width had the largest marginal effect on cooling. These results will provide useful guidance for urban climate adaptive planning and design.