scholarly journals The Effect of Plants on Extensive Green Roofs in Urban Heat Island Mitigation Efforts in Humid Tropical Cities

2021 ◽  
Vol 881 (1) ◽  
pp. 012043
Author(s):  
Irfandi ◽  
Abdul Munir ◽  
Muslimsyah ◽  
Khairul Huda
Keyword(s):  
Urban Heat Island ◽  
Ground Cover ◽  
Green Roofs ◽  
Maximum Temperature ◽  
Base Temperature ◽  
Heat Flow Rate ◽  
Heat Island ◽  
Tropical Cities ◽  
Urban Heat ◽  
Extensive Green Roofs

Abstract One of the urban heat island mitigation strategies in reducing urban temperatures in tropical cities is the application of a green roof system. This study compares the reduction in temperature and heat flow rate provided by three types of plants on extensive green roofs (EGR). We demonstrated that a EGR constructed with three types of plants (ground cover, and shrubs) could result in a decrease in temperature relative to the normal roof (NR). The results showed that the base temperature of the EGR of the bush and ground cover was lower than the base temperature of the NR which was 10.2ºC on indoor air, 17.8ºC on the inside and 19.1ºC on the outside. The peak indoor temperature was over 50ºC for the NR prototype. In the model with pennisetum purpureum schamach as the EGR, the maximum temperature was 40.1ºC, while for portulaca grandiflora and tradescantia spathacea the peaks were 37.6ºC and 37.5ºC, respectively. This shows that plants with large leaf widths are able to reduce heat greater than plants with small leaf widths.

scholarly journals The Effects of Green Roofs on Outdoor Thermal Comfort, Urban Heat Island Mitigation and Energy Savings

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 123 ◽  
Author(s):  
Guglielmina Mutani ◽  
Valeria Todeschi
Keyword(s):  
Surface Temperature ◽  
Thermal Comfort ◽  
Urban Heat Island ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Green Roofs ◽  
Heat Island ◽  
Urban Context ◽  
Urban Heat ◽  
The City

There is growing attention to the use of greenery in urban areas, in various forms and functions, as an instrument to reduce the impact of human activities on the urban environment. The aim of this study has been to investigate the use of green roofs as a strategy to reduce the urban heat island effect and to improve the thermal comfort of indoor and outdoor environments. The effects of the built-up environment, the presence of vegetation and green roofs, and the urban morphology of the city of Turin (Italy) have been assessed considering the land surface temperature distribution. This analysis has considered all the information recorded by the local weather stations and satellite images, and compares it with the geometrical and typological characteristics of the city in order to find correlations that confirm that greenery and vegetation improve the livability of an urban context. The results demonstrate that the land-surface temperature, and therefore the air temperature, tend to decrease as the green areas increase. This trend depends on the type of urban context. Based on the results of a green-roofs investigation of Turin, the existing and potential green roofs are respectively almost 300 (257,380 m2) and 15,450 (6,787,929 m2). Based on potential assessment, a strategy of priority was established according to the characteristics of building, to the presence of empty spaces, and to the identification of critical areas, in which the thermal comfort conditions are poor with low vegetation. This approach can be useful to help stakeholders, urban planners, and policy makers to effectively mitigate the urban heat island (UHI), improve the livability of the city, reduce greenhouse gas (GHG) emissions and gain thermal comfort conditions, and to identify policies and incentives to promote green roofs.

scholarly journals Mitigating Urban Heat Island Through Green Roofs

2015 ◽  
Vol 10 (Special-Issue1) ◽  
pp. 918-927 ◽  
Author(s):  
Roozbeh Arabi ◽  
Mohd Shahidan ◽  
M. S Kamal ◽  
Mohamad Jaafar ◽  
Mehdi Rakhshandehroo
Keyword(s):  
Urban Heat Island ◽  
Green Roofs ◽  
Heat Island ◽  
Urban Heat

Satellite and Ground Estimates of Surface and Canopy-Layer Urban Heat Island

2021 ◽  
Vol 12 (4) ◽  
pp. 1-21
Author(s):  
Bakul Budhiraja ◽  
Prasad Pathak ◽  
Girish Agarwal ◽  
Raja Sengupta
Keyword(s):  
Urban Heat Island ◽  
Temperate Climate ◽  
Seasonal Patterns ◽  
Heat Island ◽  
Canopy Layer ◽  
Night Time ◽  
Holistic View ◽  
Climate Zones ◽  
Tropical Cities ◽  
Urban Heat

The urban heat island (UHI) effect is one of the prominent impacts of urbanization that affects human health and energy consumption. As the data is limited and inconsistent, UHI comparative studies between UHIUCL and UHISurf on the seasonal scale are limited. The use of only daytime summer imagery reporting “Inverted UHI” undermines the holistic view of the phenomenon. Therefore, this study analyses the seasonal patterns for UHISurf and UHIUCL in three climate zones (Delhi, Pune, and Montreal). The three cities experience a high traditional night-time UHIUCL (Delhi 7°C, Pune 6°C, Montreal 1.89°C). Landsat captures a prominent daytime UHISurf (15°C) in Montreal with temperate climate and daytime inverted UHISurf (-4°C) for Delhi in summer. Seasonally, the night-time UHI is prominent in summer and monsoon for Delhi, summer and spring for Pune, and summer for Montreal. Due to UHI effect, the heatwaves can be more intense in semi-arid and tropical cities than temperate cities.

Impact of mass human migration during Chinese New Year on Beijing urban heat island

2020 ◽  
Author(s):  
Jingjing Dou ◽  
Shiguang Miao
Keyword(s):  
Spatial Distribution ◽  
Urban Heat Island ◽  
Human Migration ◽  
Floating Population ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Heat Island ◽  
Urban Heat ◽  
The Impact

<p>The Chinese New Year (CNY, also called Spring Festival), which officially lasts for 7 days, is the most important holiday in China. Chinese people in large cities usually return to their hometowns for family reunions before the CNY holiday and return afterward. Nearly half of Beijing’s population has been reported to leave the city for family reunions before the CNY holidays in the past several years. Hourly automatic weather station (AWS) data during CNY 2010-2015 were used to analyze the changes in the temporal and spatial distribution of the Beijing urban heat island intensity (UHII) and the impact of mass human migration on urban temperature. Soil moisture, 10-m wind speed, and cloud cover were considered and indicated nearly no change during the pre-CNY period (2 to 4 weeks before CNY) and CNY week, which means that UHII variation was mainly affected by the mass human migration. Daily UHII during CNY week was lower than during pre-CNY period. UHII for daily maximum temperature decreased by 55% during CNY week than the pre-CNY period (0.6 °C during pre-CNY period vs. 0.27 °C during CNY week) due to mass human migration, which was much larger than the reduction in UHII for the daily maximum temperature (5%, 4.34 °C during the pre-CNY period vs. 4.11 °C during the CNY week). The spatial distribution of the UHII difference between CNY week and the pre-CNY period is closely related to the locations of functional population zones. UHII for daily maximum temperature decreases most (80%, 0.40 °C during the pre-CNY period vs. 0.08 °C during the CNY period) between the Third and Fourth Ring Roads (RRs), an area which experiences high human activity and has the highest floating population percentage. This study can provide suggestions for optimizing the layout of urban space and land-use structures.</p>

Green roofs as a strategy for urban heat island mitigation in Bologna (Italy)

2018 ◽  
pp. 295-300
Author(s):  
S.S. Cipolla ◽  
M. Maglionico ◽  
G. Semprini ◽  
V. Villani ◽  
A. Bonoli
Keyword(s):  
Urban Heat Island ◽  
Green Roofs ◽  
Heat Island ◽  
Urban Heat

scholarly journals The Urban Heat Island Analysis of Changsha-zhuzhou-xiangtan Urban Agglomeration Aased on Modis Data

2018 ◽  
Vol 53 ◽  
pp. 03045
Author(s):  
Jiao Yuan ◽  
Jingwen Li ◽  
Suxian Ye ◽  
Xiaoqiang Han ◽  
Yao Hu
Keyword(s):  
Urban Heat Island ◽  
Temperature Difference ◽  
Land Surface ◽  
Temporal Distribution ◽  
Maximum Temperature ◽  
Heat Island ◽  
Maximum Temperature Difference ◽  
High Temperature Area ◽  
Urban Heat ◽  
The Difference

Using a spatial resolution of MODIS land 1000m standard products, we can get the Land Surface Temperature.Researching for the Land Surface Temperature including spatial and temporal distribution characteristics influence factors.The results show that Spring,Summer and Autumn temperatures mainly concentrated in the central region,Winter temperature mainly concentrated in the South region.From 2001 to 2015,the maximum temperature difference is summer daytime and the difference is 17.58°C,the minimum temperature difference is autumn daytime and the difference is 11.3°C.According to the thermal field intensity distribution,compared 2005 with 2015,Urban Heat Island intensity gradually increased in 2015,the high temperature area increased and distributed more concentrated,and diffusion weakened from the city to the surrounding,the urban heat field is higher than the thermal field.That index by calculating the thermal landscape,account for a dominant position in the middle of heat distribution,and all types index in 2015 are higher than in 2005.

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