Impacts of urban form and urban heat island on the outdoor thermal comfort: a pilot study on Mashhad

2021 ◽  
Author(s):  
Elham Sanagar Darbani ◽  
Danial Monsefi Parapari ◽  
John Boland ◽  
Ehsan Sharifi
Keyword(s):  
Pilot Study ◽  
Thermal Comfort ◽  
Urban Heat Island ◽  
Urban Form ◽  
Outdoor Thermal Comfort ◽  
Heat Island ◽  
Urban Heat

scholarly journals Biomimicry-Based Strategies for Urban Heat Island Mitigation: A Numerical Case Study under Tropical Climate

Biomimetics ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 48
Author(s):  
Kevin Araque ◽  
Paola Palacios ◽  
Dafni Mora ◽  
Miguel Chen Austin
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Outdoor Thermal Comfort ◽  
Base Case ◽  
Heat Island ◽  
Urban Heat ◽  
Historical Heritage ◽  
Pet Index ◽  
Radiant Temperature

In recent years, demographic growth has caused cities to expand their urban areas, increasing the risk of overheating, creating insurmountable microclimatic conditions within the urban area, which is why studies have been carried out on the urban heat island effect (UHI) and its mitigation. Therefore, this research aims to evaluate the cooling potential in the application of strategies based on biomimicry for the microclimate in a historical heritage city of Panama. For this, three case studies (base case, case 1, and case 2) of outdoor thermal comfort were evaluated, in which the Envi-met software was used to emulate and evaluate the thermal performance of these strategies during March (highest temperature month) and October (rainier month). The strategies used were extracted from the contrast of zebra skin, human skin, evaporative cooling, and ant skin. The results showed a reduction of 2.8 °C in the air temperature at 11:00, the radiant temperature decreased by 2.2 °C, and the PET index managed to reduce the thermal comfort indicator among its categories. The importance of thinking based on biomimicry in sustainable strategies is concluded; although significant changes were obtained, high risks of discomfort persist due to the layout and proximity of the building.

scholarly journals Cooling Strategies for Thermal Comfort in Cities: A Review of Key Methods in Landscape Design

2021 ◽  
Author(s):  
Mo Zou ◽  
Heng Zhang
Keyword(s):  
Urban Planning ◽  
Thermal Comfort ◽  
Urban Heat Island ◽  
Landscape Design ◽  
Urban Morphology ◽  
Outdoor Thermal Comfort ◽  
Theoretical Research ◽  
Heat Island ◽  
Design Elements ◽  
Urban Heat

Abstract Under the climate change scenario, the negative impacts of urban heat island (UHI) will exacerbate due to unsustainable urban planning and human activities. Thermal comfort has close relationships with UHI in urban areas. This paper is based on the studies of urban heat island, thermal comfort, microclimate and urban planning in cities in the recent decade, combined with cross-analysis research method. The key topics include vegetation and water conditions, the albedo of materials, urban morphology and more. By the comparative case studies in landscape projects, the results further reveal that the density of tree canopies, the natural structure and density of ground cover, the form of water features, the colour and texture of materials, and the scale of shading structures have different cooling effect and performance in outdoor thermal comfort improvement with specific features in the landscape design. It is also found that there are some external conditions that can influence design determinations in real practices. The purpose of this study is to provide theoretical research methods and evaluation of thermal comfort landscape design elements, and to provide guidance for future sustainable city research and landscape design.

scholarly journals Green Envelop Impact on Reducing Air Temperature and Enhancing Outdoor Thermal Comfort in Arid Climates

2019 ◽  
Vol 5 (5) ◽  
pp. 1124-1135 ◽  
Author(s):  
Sherine Wahba ◽  
Basil Kamil ◽  
Khaled Nassar ◽  
Ahmed Abdelsalam
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Electricity Consumption ◽  
Green Roofs ◽  
Mean Value ◽  
Outdoor Thermal Comfort ◽  
Heat Island ◽  
Consumption Rates ◽  
Urban Heat

Today Urban Cities faces energy and environmental challenges due to increased population, higher urbanization. The building sector has a big responsibility as it acquires high consumption rates in global energy and environmental scenarios. It is thought that the built environment in Egypt is responsible for 26% of the total overall national energy consumption, 62% of the total electricity consumption and around 70% of resultant CO2 emissions. The increased use of electrical appliances causes Urban Heat Island effect (UHI), which affect major urban centres. Adding green elements to any urban area is proved to be an effective strategy with numerous benefits to enhance the city's ecosystem, also mitigate the urban heat island measures. In this research Green roofs/walls can regulate outdoor air temperature by 10°C and improve outdoor thermal comfort by 2 Predicted Mean Value (PMV) values. The modelling of green strategy models can take into consideration design developments in areas with hot and dry climatic zones. The properties of green walls can directly affect the results of thermal comfort as leafs absorbs, reflects and transmits solar radiation, and increases the evapotranspiration.

OVERVIEW OF URBAN HEAT ISLAND (UHI) PHENOMENON TOWARDS HUMAN THERMAL COMFORT

2017 ◽  
Vol 16 (9) ◽  
pp. 2097-2111 ◽  
Author(s):  
Mohanadoss Ponraj ◽  
Yee Yong Lee ◽  
Mohd Fadhil Md Din ◽  
Zainura Zainon Noor ◽  
Kenzo Iwao ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat

scholarly journals Seasonal and Diurnal Variations in the Relationships between Urban Form and the Urban Heat Island Effect

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5909
Author(s):  
Ze Liang ◽  
Yueyao Wang ◽  
Jiao Huang ◽  
Feili Wei ◽  
Shuyao Wu ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Form ◽  
Urban Heat Island Effect ◽  
Dominant Factor ◽  
Heat Island ◽  
Relative Contribution ◽  
Island Effect ◽  
Urban Geometry ◽  
Seasonal And Diurnal Variations ◽  
Urban Heat

At the city scale, the diurnal and seasonal variations in the relationship between urban form and the urban heat island effect remains poorly understood. To address this deficiency, we conducted an empirical study based on data from 150 cities in the Jing-Jin-Ji region of China from 2000 to 2015. The results derived from multiple regression models show that the effects of urban geometric complexity, elongation, and vegetation on urban heat island effect differ among different seasons and between day and night. The impacts of urban geometric factors and population density in summer, particularly those during the daytime, are significantly larger than those in winter. The influence of urban area and night light intensity is greater in winter than in summer and is greater during the day than at night. The effect of NDVI is greater in summer during the daytime. Urban vegetation is the factor with the greatest relative contribution during the daytime, and urban size is the dominant factor at night. Urban geometry is the secondary dominant factor in summer, although its contribution in winter is small. The relative contribution of urban geometry shows an upward trend at a decadal time scale, while that of vegetation decreases correspondingly. The results provide a valuable reference for top-level sustainable urban planning.

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