Urban Heat Island Intensity in Chiang Mai City Using Mobile Surveying Approach

2014 ◽  
Vol 931-932 ◽  
pp. 605-613
Author(s):  
Pisut Sangnum ◽  
Niti Kammuang-Lue ◽  
P. Sakulchangsatjatai ◽  
P. Terdtoon
Keyword(s):  
Population Density ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Ambient Air ◽  
Urban Heat Island Intensity ◽  
Traffic Density ◽  
Heat Island ◽  
Chiang Mai ◽  
Ambient Air Temperature ◽  
Urban Heat

This research aims to evaluate on Urban Heat Island Intensity in Chiang Mai city and to study effects of population density, building density and traffic density on ambient air temperature. The ambient air temperature was measured by thermocouples at a constant altitude of 2 m above the road. The surveyed routes were divided to urban routes and rural routes. The Urban Heat Island Intensity (UHII) was calculated from an average ambient air temperature difference between urban and rural areas. Experimental investigations were carried out in 2 periods, which were a day time (12.30-02.30 pm) and a night time (10.00 pm-00.00 am) on Monday, Wednesday, and Sunday in summer time (March-May, 2013). The results show that the UHII in Chiang Mai city in a day time is +1.1 °C and in a night time is +1.3 °C. Moreover, the population density, building density and traffic density were found to have significant effects on ambient air temperature, especially the population density and building density have direct effect on ambient air temperature. However, the traffic density has direct effect on ambient air temperature only in a day time.

scholarly journals Evaluating the Effectiveness of Mitigation Options on Heat Stress for Sydney, Australia

2018 ◽  
Vol 57 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Shaoxiu Ma ◽  
Andy Pitman ◽  
Jiachuan Yang ◽  
Claire Carouge ◽  
Jason P. Evans ◽  
...  
Keyword(s):  
Heat Stress ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Ambient Air ◽  
Mitigation Strategies ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Ambient Air Temperature ◽  
Populations At Risk ◽  
Urban Heat

AbstractGlobal warming, in combination with the urban heat island effect, is increasing the temperature in cities. These changes increase the risk of heat stress for millions of city dwellers. Given the large populations at risk, a variety of mitigation strategies have been proposed to cool cities—including strategies that aim to reduce the ambient air temperature. This paper uses common heat stress metrics to evaluate the performance of several urban heat island mitigation strategies. The authors found that cooling via reducing net radiation or increasing irrigated vegetation in parks or on green roofs did reduce ambient air temperature. However, a lower air temperature did not necessarily lead to less heat stress because both temperature and humidity are important factors in determining human thermal comfort. Specifically, cooling the surface via evaporation through the use of irrigation increased humidity—consequently, the net impact on human comfort of any cooling was negligible. This result suggests that urban cooling strategies must aim to reduce ambient air temperatures without increasing humidity, for example via the deployment of solar panels over roofs or via cool roofs utilizing high albedos, in order to combat human heat stress in the urban environment.

scholarly journals Spatiotemporal Changes in the Built Environment Characteristics and Urban Heat Island Effect in a Medium-Sized City, Chiayi City, Taiwan

2020 ◽  
Vol 12 (1) ◽  
pp. 365 ◽  
Author(s):  
Jou-Man Huang ◽  
Heui-Yung Chang ◽  
Yu-Su Wang
Keyword(s):  
Population Density ◽  
Built Environment ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Area Ratio ◽  
Heat Island ◽  
Downtown Area ◽  
Green Area ◽  
Spatiotemporal Changes ◽  
Urban Heat

This study took Chiayi City—a tropical, medium-sized city—as an example to investigate the urban heat island (UHI) effect using mobile transects and built environment characteristics in 2018. The findings were compared to those from a study in 1999 to explore the spatiotemporal changes in the built environment characteristics and UHI phenomenon. The result for the UHI intensity (UHII) during the day was approximately 4.1 °C and at midnight was approximately 2.5 °C. Compared with the survey in 1999, the UHII during the day increased by approximately 1.3 °C, and the UHII at midnight decreased by approximately 1.2 °C. The trend of the spatial distribution of the increasing artificial area ratio (AAR) proved the importance of urban land use expansion on UHI. The results of the air temperature survey were incorporated with the nesting space in GIS to explore the role of built environment characteristics in UHI effects. The higher the population density (PD) and artificial area ratio (AAR) were, the closer the proximity was to the downtown area. The green area ratio (GAR) was less than 0.2 in the downtown area and increased closer to the rural areas. The built environment factors were analyzed in detail and correlated with the UHI effect. The air temperature in the daytime increased with the population density (PD) and artificial area ratio (AAR), but decreased with the green area ratio (GAR) (r = ±0.3–0.4). The result showed good agreement with previous studies.

scholarly journals Analysis of the urban heat island intensity based on air temperature measurements in a renovated part of Budapest (Hungary)

2019 ◽  
Vol 23 (4) ◽  
pp. 277-288 ◽  
Author(s):  
Csenge Dian ◽  
Rita Pongrácz ◽  
Dóra Incze ◽  
Judit Bartholy ◽  
Attila Talamon
Keyword(s):  
Urban Heat Island ◽  
Air Temperature ◽  
Temperature Measurements ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Urban Heat

scholarly journals Retrofitting solutions for a campus building to mitigate urban heat island in a hot humid climate

2021 ◽  
Vol 2042 (1) ◽  
pp. 012062
Author(s):  
Vajreshwari Patil ◽  
Maite Bizcarguenaga ◽  
Katherine Lieberknecht ◽  
Juliana Felkner
Keyword(s):  
Surface Temperature ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Ambient Air ◽  
Cooling Effect ◽  
Heat Island ◽  
Humid Climate ◽  
Temperature Reduction ◽  
Urban Heat ◽  
Hot Humid Climate

Abstract In this study we examine the summer cooling effects of trees and green facades on reducing urban heat island effects. Using ENVI-met model simulations, we investigate the influence of added greenery on the surface and ambient air temperature and its role on air fluctuations in the hot humid climate of Austin, TX, at pedestrian height. Under the specific conditions considered in this model, the results show the combination of trees and green facades has a greater cooling effect. Added greenery to the building mostly impacts the building's surface temperature during the hottest hours of the day, registering a maximum surface temperature reduction of 20.33°C. Simulations also show a maximum overall potential air temperature reduction of 0.54°C, and a maximum potential air temperature cooling effect near the building of 0.91°C. Future research should be conducted to address this study's limitations. Nevertheless, these findings can provide architects, designers, planners, and policymakers with a better understanding of the many benefits trees and green facades have, and provide them with the necessary tools to implement new solutions across sectors and scales to reduce the impacts urban areas have on the environment and provide a better living for all.

Temperature adjustments for design data for urban air conditioning design

2017 ◽  
Vol 39 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Geoffrey Levermore ◽  
Stefan Vandaele ◽  
John Parkinson
Keyword(s):  
Urban Heat Island ◽  
Air Temperature ◽  
Air Conditioning ◽  
Solar Irradiation ◽  
Urban Heat Island Intensity ◽  
Wave Radiation ◽  
Urban Air ◽  
Heat Island ◽  
Urban Heat ◽  
Radiant Temperature

The urban heat island, where the urban area air temperature is higher than the nearby rural or semi-rural air temperature reference site, is now hopefully well known. The urban heat island intensity is the actual urban air temperature minus the rural air temperature. However, the “air conditioned urban heat island intensity” is measured by the air temperature sensor in an air conditioning condenser unit minus the rural air temperature. This is often different to the standard urban heat island intensity. Designers need to appreciate this difference, as it determines how the air conditioning system performs. It is most likely affected by the radiant temperature. This can also vary significantly from the rural, semi-rural radiant temperature due to the variation in solar absorptance of the urban buildings and the shading effects. Measurements have shown significant variations in the infrared temperatures over the urban areas. Calculations of the radiant absorption and long wave radiation loss also show significant differences to the rural counterparts in frequency and magnitude. This “surface urban heat island” is important for air conditioning plant situated often in areas exposed to solar irradiation. The exhaust air from the air conditioning units itself is also briefly considered. This paper examines these effects and proposes how the engineer can include for them in design. Practical application:The results of this paper will be useful for designers of buildings with air conditioning and air conditioning plant itself to assess the effect of the micro urban heat island. This micro urban heat island surrounds the air conditioning plant. The example is for London.

scholarly journals Influences of population, building, and traffic densities on urban heat island intensity in Chiang Mai City, Thailand

2015 ◽  
Vol 19 (suppl. 2) ◽  
pp. 445-455 ◽  
Author(s):  
Niti Kammuang-Lue ◽  
Phrut Sakulchangsatjatai ◽  
Pisut Sangnum ◽  
Pradit Terdtoon
Keyword(s):  
Urban Heat Island ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Chiang Mai ◽  
Urban Heat
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