Search Results (853)

Abstract: Numerous issues with the urban thermal environment have been brought on by the rapid development of urbanization. The thermal climate of the slow lane, a major urban activity area, is directly tied to the well-being and comfort of city dwellers. The Swan Lake area in Hefei was chosen as the research site for this paper. The mobile measurement method was used to determine the heat island intensity distribution of the slow lane in each season of the year. The effects of building density, the percentage of permeable underlying surface, and shading on the slow lane’s thermal environment were then thoroughly examined. According to the study, the distribution of heat island intensities along the mobile measurement route varies significantly depending on season, as well as time of year. Summer and winter have the most notable variations in the distribution of heat island intensities along the mobile measurement route; the summer values range from 0.1 to 4, while the winter values range from −0.3 to 3. The results showed a maximum difference of 30.2 °C in surface temperature (Ts) readings and 11.9 °C in air temperature (Ta) readings between the identical sites with and without shading, according to tests conducted at four typical mobile measurement locations along the mobile measuring route. The shading factor has a greater effect on the slow lane’s thermal environment than permeable underlying surface and building density, as seen by the standardized coefficient of shading being significantly higher than both of these factors. With a standardized coefficient of shading of −0.493 in the winter and a standardized coefficient of shading of −0.517 in the summer, the effect of the shading factor on the thermal environment is more noticeable in the summer. Full article

Digital twin technology us used to create accurate virtual representations of objects or systems. Digital twins span the object’s life cycle and keep updated with real-time data. Therefore, their simulation capabilities can be combined with deep learning to create a system that simulates scenarios, enabling analysis. As cities continue to grow and the demand for sustainable development increases, digital twin technology, combined with AI-driven analysis, will play a critical role in shaping the future of urban environments. The ability to accurately simulate and manage complex systems in real time opens up new possibilities for optimizing energy usage, reducing costs, and improving the quality of life for urban residents. In this study, a digital twin application is built to visualize a smart area in South Korea, utilizing a deep learning model for personal thermal comfort analysis, which can be useful for managing and saving building and household energy consumption. Using Cesium for Unreal, a powerful tool for integrating 3D geospatial data, and leveraging DataSmith to convert 3D data into Unreal Engine format, this study also contributes a roadmap for smart city application development, which is currently considered to be lacking. By creating a robust framework for smart city applications, this research not only addresses current challenges but also lays the groundwork for future innovations in urban planning and management. Full article

The surging global population and urbanization trends present new challenges to food production systems and energy, especially in resource-limited urban environments. Vertical farming on façades (VFOF) is an innovative strategy to address this challenge by growing crops on building skins, efficiently using urban space, increasing food self-sufficiency, and reducing the environmental impact of carbon emissions. This article is a comprehensive review of VFOF and closely related topics based on 166 journal articles. It covers the latest research advances in design, technology, social impact, and environmental benefits. In addition to enhancing the autonomy of urban food supply and improving residents’ quality of life, VFOF also has the potential to optimize the thermal performance of buildings and promote energy conservation by having some of the qualities of vertical greening systems (VGS). The planting system design and technical support factors for different façade locations are explained in detail. The symbiotic relationship between VFOF and architecture is examined to enhance sustainability. The popularity of VFOF is increasing in terms of social acceptance, and the government, together with the private sector and communities, play a vital role in promoting its development. In addition, this review also collates the cases of VFOF implementation in recent years. Research shows that the implementation of VFOF has many advantages, especially when considering future urban challenges under climate change scenarios and the need to provide solutions to achieve carbon neutral buildings and cities. Still, high initial investment, operating costs, technical complexity, security issue, policy and regulatory constraints, and public acceptance are all challenges to overcome. Further research should be carried out in the above fields. Full article

The urban heat island effect (UHI) has become a major challenge for sustainable urban development. In recent decades, the significant development of urban agglomerations has intensified the complex interaction and comprehensive impact of the UHI effect, but the spatiotemporal pattern of regional heat islands has been poorly understood. Based on the land surface temperature (LST) from 2001 to 2020, this study uses the relative land surface temperature (RLST) method to quantify the regional heat island (RHI) of the Central Yunnan Urban Agglomeration (CYUA) beyond a single city, combines a variety of spatial analysis tools to identify the multi-scale spatiotemporal pattern, and explores the multidimensional driving factors of RHIs. The combined effects of indicators such as urbanization intensity, blue–green space intensity (2D), and building height characteristics (3D) on the mitigation or exacerbation of RHIs are included. The results are as follows: (1) The RHI was significantly enhanced, especially during 2011–2014, when the heat island intensity and influence range expanded rapidly, especially in the core areas such as Kunming and Qujing. (2) The main urban areas of prefecture-level cities have a greater contribution to the RHI, and the intercity heat interaction further intensifies the heat island effect on county-level regions. (3) Different land cover types have different effects on RHI. The human and social factors have a positive effect on the RHI, the blue–green intensity has a strong inhibitory effect, and the cooling effect of blue space is better than that of green space. Topographic and meteorological factors have little influence. To effectively address the challenge of UHI, the CYUA must strengthen the construction of green infrastructure, optimize urban planning, promote energy conservation and emission reduction, and improve climate adaptation planning. This paper discusses the spatiotemporal variation in the heat island effect and the influencing factors from a new regional perspective, which enriches the research content of urban agglomeration thermal environment and improves the research system of the heat island effect. Full article

The critical and urgent issue of decarbonization by 2050 needs to include the existing historical built environment in the process of energy requalification. These buildings, subjected to heritage preservation, are extremely inadequate to the modern standards of energy efficiency and thermal comfort, and they exhibit the poorest energy performance. In this study, a review of the existing scientific literature on the matter of energy renovation processes applied to historic buildings is provided. The reviewed papers, selected from scientific databases, were initially categorized according to their reference scale—either individual buildings or urban contexts. Subsequently, the papers were grouped on the basis of the main energy efficiency levels they investigated. The goal is to offer a comprehensive overview of the materials, technologies and strategies currently in use, as well as future perspectives, to aid the ecological transition and foster sustainable development, all while preserving the artistic, cultural and architectural heritage of these buildings. Full article

Traditional rooftop greenhouses offer a promising solution for urban vegetable supply but have the disadvantages of overheating during the daytime and supercooling during the nighttime. To address these issues, a novel solar greenhouse system using nanofluid spectral splitting and phase change materials (NSS-PCMs) was developed. In this study, a 75-day thermal environment test experiment was conducted on the novel solar greenhouse, and the growth status and nutrient composition of three typical plants were evaluated. By optimizing the greenhouse structure parameters through the model, over 80% of 300–800 nm wavelengths for vegetable photosynthesis were transmitted to the greenhouse, while the remaining spectrum was used for heat storage to maintain warmth during nighttime. The novel solar greenhouse reduced daytime temperatures by 5.2 °C and increased nighttime temperatures by 6.9 °C, reaching a maximum thermal efficiency of 53.4% compared to traditional greenhouses. The 75-day temperature detection showed that optimal temperature ranges were maintained for approximately 60 days, both during daytime and nighttime, with an 80% assurance rate. The growth rates of three vegetables in the novel solar greenhouse improved by 55%, 35%, and 40%, and the nutrient composition doubled compared to the control group. Full article

The thermal and optical behavior of different elements in the urban environment is critical for urban climate regulation and planning. This study investigates the micrometeorological conditions prevailing in an urban green space (UGS) in Greece, during the heatwave of July 2023, addressing the effects of various surface materials on thermal dynamics and the urban heat island (UHI) phenomenon. The research is based on ground surface temperature and albedo measurements on different materials in the UGS, in the morning and at noon, showing great temperature differences between the different types of materials. The findings highlight the complex interaction between high-albedo surfaces and surface temperature values, suggesting that the proper selection of materials can highly affect the optical and thermal behavior of the urban environment. Artificial materials absorb more heat compared to natural vegetation, leading to high surface temperature values, reaching at noon, for example, 58.9 °C for asphalt. For the natural surfaces, dry bare soil presents similar thermal behavior (64.1 °C at noon), while green surfaces had much lower temperatures (e.g., 38.3 °C for grass). Thermal comfort indices revealed that July 2023 experienced extensive “very hot” conditions, imposing the urgent need for strategic urban planning to mitigate heat impacts. The study highlights that in order to create climate-resilient environments and improve thermal comfort, it is crucial to include suitable materials and a variety of vegetation in urban design. Such insights into the complex nature of urban microclimate indicates also the issue of the careful selection of materials and plant species in urban greening initiatives to help cities face the UHI phenomenon. Full article

In recent years, the surge in air-conditioning ownership and usage has led to significant heat rejection, impacting the surrounding atmosphere. Despite this, studies examining the spatiotemporal effects of air-conditioning heat rejection at a block scale remain limited. Additionally, comparative studies on the role of building areas with air-conditioning systems versus natural underlying surfaces in the urban thermal environment are relatively scarce. This study employs field measurements and ArcGIS technology to investigate the local thermal and humidity environments, as well as the spatiotemporal distribution of heat rejection from air-conditioning systems in Wuyi Square, Changsha. Results show that cooling tower exhausts in commercial buildings maintain relative humidity levels of 95.2% to 99.8% during the day, enhancing surrounding humidity. At night, the humidity aligns with atmospheric levels (from 50.3% to 62.5%). The cooling tower exhaust temperature is approximately 2.2 °C lower during the day and 2.4 °C higher at night compared to the surrounding temperatures. In contrast, exhausts from split-type air-conditioning units in residential buildings have an average relative humidity about 14.2% lower than the atmosphere humidity, with temperature averages being 5.2 °C higher during the day and 6.5 °C higher at night, raising surrounding temperatures. The study also finds that natural surface areas are up to 3.1 °C cooler and 9.6% more humid compared to built environment surfaces. Furthermore, residential areas have air temperatures about 0.3 °C higher than commercial zones, with a humidity distribution approximately 0.5% lower. These findings offer a theoretical foundation for enhancing urban thermal environments and informing urban planning and design. Full article

This study investigates the impact of spatial changes over a 400-year period on the summer microclimate of a residential courtyard in China. Using ENVI-met simulations, we analyze how factors such as courtyard orientation, building height, and opening positions affect the thermal environment. The results show that east–west-oriented courtyards experienced 0.2–0.4 °C lower daytime temperatures compared to north–south ones. Additionally, taller surrounding buildings increased the courtyard’s average daytime temperature by approximately 0.3–0.5 °C, while courtyards with a single opening facing the prevailing wind maintained the lowest temperatures. These findings underscore the importance of historical spatial characteristics in shaping microclimates and offer key insights for contemporary urban planning. By incorporating design strategies based on these historical spatial features, such as optimizing courtyard orientation, enhancing building height variability, and creating appropriate openings for natural ventilation, urban planners can improve microclimate conditions, reduce reliance on mechanical cooling, and enhance energy efficiency. This approach not only contributes to lowering carbon emissions but also boosts resilience to extreme heat events in urban areas, especially in regions facing rapid urbanization and climate change challenges. Full article

Amidst the increasingly escalating global concern regarding climate change, adopting a low-carbon approach has become crucial for charting the future developmental trajectory of urban areas. It also offers a novel angle for cities to avoid high-temperature risks. This paper estimates carbon emissions in Wuhan City from both direct and indirect aspects. Then, the ANN (artificial neural network)–CA (Cellular Automata) model is employed to establish three distinct development scenarios (Ecological Priority, Tight Growth, and Natural Growth) to predict future urban expansion. Additionally, the WRF (Weather Research and Forecasting Model)—UCM (Urban Canopy Model) model is used to investigate the thermal environmental impacts of varying urban development scenarios. This study uses a low-carbon perspective to explore how cities can develop scientifically sound urban strategies to meet climate change challenges and achieve sustainable development goals. The conclusions are as follows: (1) The net carbon emission for Wuhan in 2022 is estimated to be approximately 20.8353 million tonnes. Should the city maintain an average annual emission reduction rate of 10%, the carbon sink capacity of Wuhan would need to be enhanced by 382,200 tonnes by 2060. (2) In the absence of anthropogenic influence, there is a propensity for the urban construction zone of Wuhan to expand primarily towards the southeast and western sectors. (3) The Ecological Priority (EP) and Tight Growth (TG) scenarios are effective in alleviating the urban thermal environment, achieving a reduction of 0.88% and 2.48%, respectively, in the urban heat island index during afternoon hours. In contrast, the Natural Growth (NG) scenario results in a degradation of the urban thermal environment, with a significant increase of over 4% in the urban heat island index during the morning and evening periods. (4) An overabundance of urban green spaces and water bodies could exacerbate the urban heat island effect during the early morning and at night. The findings of this study enhance the comprehension of the climatic implications associated with various urban development paradigms and are instrumental in delineating future trajectories for low-carbon sustainable urban development models. Full article

The worsening urban thermal environment has become a critical challenge in many cities. Trees, as vital components of urban green spaces, provide multiple ecosystem services, especially in improving the microclimate. However, limited studies address how morphological changes during tree growth influence their cooling benefits. This study combined the tree growth model with ENVI-met to simulate 27 scenarios in a subtropical urban square, considering three planting intervals, three urban tree species, and three growth stages to evaluate their daytime thermal impacts. The key findings include: (1) Tree size and planting intervals are more important than tree quantity in enhancing thermal comfort. (2) Reducing intervals by 2 m enhances cooling effects but minimally affects PET (physiological equivalent temperature). (3) Increasing DBH (diameter at breast height) significantly improves cooling. For every 10 cm increase in DBH, Michelia alba, Mangifera indica, and Ficus microcarpa L. f. reduced solar radiation by 19.54, 18.09, and 34.50 W/m², and mean radiant temperature by 0.61 °C, 0.68 °C, and 1.35 °C, respectively, while decreasing PET by 0.23 °C, 0.23 °C, and 0.46 °C. These findings provide empirical evidence and practical recommendations for designing comfortable open spaces in subtropical cities. Full article

In recent climate-adaptive design strategies, there has been a growing interest in creating healthy and comfortable urban microclimates. However, not enough attention has been paid to the influence of street interface morphology in order to better understand the wind–thermal conditions of various commercial streets within the city and create a sustainable built environment. This research summarizes and categorizes commercial streets according to their functions and types of attributes and then abstracts the ideal models of three types of typical commercial streets to explore the effects of changes in specific morphological parameters on their wind–thermal environments. Firstly, this study selects out design parameters that affect the street interface morphology. Then, it uses the numerical simulation software PHOENICS2019 to simulate and investigate the effects of three types of typical commercial street interface morphology on their wind environment and thermal comfort. The results show that (1) in neighborhood-commercial streets, reducing void ratio and variance of height fluctuations can enhance the average wind speed of the street while reducing average temperature and improving the thermal comfort; (2) in business-office streets, the value of the void ratio is negatively correlated with the wind environment and thermal comfort, while the changes in the variance of height fluctuations and the average aspect ratio are positively correlated; and (3) in comprehensive-commercial streets, the decrease of the void ratio will reduce the average wind speed of its street and increase the average temperature, thus weakening the thermal comfort of pedestrians. In contrast, the variance of height fluctuations as well as the average aspect ratio do not significantly affect its wind–thermal environment. These conclusions from this research provide a theoretical basis and methodological reference for the creation of safer, resilient and sustainable built environments. Full article

Dynamic development of tourism activities and rapid urbanisation in Special Economic Zones (SEZs) can lead to significant land use and land cover changes (LULCCs) and environmental degradation, particularly in ecologically sensitive areas. This study examines the transformation of land use and its associated impacts on habitat quality and thermal environment in Phu Quoc Island (Vietnam) over a 20-year period (2003–2023). Using multi-temporal Landsat satellite imagery and random forest classification, we quantify LULCCs and assess the environmental consequences of urban expansion on habitat degradation and intensification of the island’s thermal environment, focusing on land surface temperature (LST) changes. Our analysis reveals that rapid urbanisation, driven by large-scale tourism and infrastructure developments, has led to a significant loss of forest and farmland, leading to a 5.6% decline in habitat quality and a marked increase in LST. The study also highlights the uneven distribution of urban growth, with the majority of expansion occurring in the southern and central regions of the island. By applying the InVEST Habitat Quality Model, we identify key zones of habitat degradation and offer insights into the spatial patterns of environmental sensitivity and changes. Our findings underscore the need for integrated land use planning and sustainable development strategies to mitigate the negative environmental impacts of SEZ-driven urbanisation on island ecosystems. This research provides critical guidance for policymakers, planners, and environmental managers to balance economic growth with environmental conservation in fragile island environments. Full article

(1) Background: Metro is an important part of urban transportation, carrying huge passenger volume every day. With improvements in people’s living standards, passengers’ demand for a comfortable Metro experience is increasing. In the context of urban development, maintaining a good thermal comfort level of Metro cars is not only conducive to providing a comfortable and healthy environment for passengers, but also has great significance for reducing energy consumption and sustainable urban transportation development. This study provides empirical evidence for Metro design and operation strategies, aiming at creating a safer and more comfortable passenger experience. (2) Methods: By combining passengers’ comfort perception (cognitive value of thermal environment) and rideability perception (confidence in thermal comfort control), this study established a correlation model between thermal comfort and passenger unsafe behavior, namely the integration of SOR (Stimulus-Organism-Response) and TAM (Technology Acceptance Model). This study used methods such as field surveys, structural equation modeling, and reliability and validity analyses to investigate the impact of Metro thermal comfort on passenger behavior safety. (3) Results: This study found that the Metro thermal environment, including temperature, humidity, and airflow velocity, significantly affects passengers’ comfort perception and behavior choices. (4) Conclusions: Passengers may exhibit avoidance behavior in uncomfortable thermal environments, leading to uneven distribution of people in the train car and increasing safety risks. Improving Metro thermal environments can effectively enhance passengers’ perceived comfort and reduce unsafe behavior motivation, which is of great significance for safe Metro operations. Full article

The integration of pedestrian movement analysis with Unmanned Aerial Vehicle (UAV)-based remote sensing enables comprehensive monitoring and a deeper understanding of human dynamics within urban environments, thereby facilitating the optimization of urban planning and public safety strategies. However, human behavior inherently involves uncertainty, particularly in the prediction of pedestrian trajectories. A major challenge lies in modeling the multimodal nature of these trajectories, including varying paths and targets. Current methods often lack a theoretical framework capable of fully addressing the multimodal uncertainty inherent in trajectory predictions. To tackle this, we propose a novel approach that models uncertainty from two distinct perspectives: (1) the behavioral factor, which reflects historical motion patterns of pedestrians, and (2) the stochastic factor, which accounts for the inherent randomness in future trajectories. To this end, we introduce a global framework named LSN-GTDA, which consists of a pair of symmetrical U-Net networks. This framework symmetrically distributes the semantic segmentation and trajectory prediction modules, enhancing the overall functionality of the network. Additionally, we propose a novel thermal diffusion process, based on signal and system theory, which manages uncertainty by utilizing the full response and providing interpretability to the network. Experimental results demonstrate that the LSN-GTDA method outperforms state-of-the-art approaches on benchmark datasets such as SDD and ETH-UCY, validating its effectiveness in addressing the multimodal uncertainty of pedestrian trajectory prediction. Full article