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Constructions and related matters relevant to environmental health
Published in Stephen Battersby, Clay's Handbook of Environmental Health, 2023
John Bryson, Stephen Battersby
“Cool” roofs (usually light in colour) are roofing systems that can deliver high solar reflectance (albedo) and have the ability to reflect the visible, infrared and ultra-violet wavelengths of sunlight and reduce heat transfer to the building. They also have high thermal emittance (the ability to radiate absorbed or non-reflected solar energy). “Green roofs”, sometimes known as “living roofs”, are roofs that are partially or wholly covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems. They serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife, and helping to lower urban air temperatures. Both forms of roof counter the heat island effect. An urban heat island is an urban area that has significantly higher temperatures than surrounding rural or less densely populated areas.
Urban and peri-urban agriculture
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
One of the best ways to mitigate the urban heat island effect is to increase the amount of vegetation in the city. Urban gardens and other agricultural sites work just as well in this respect as parks and street trees, especially when they include trees. Plants exert their cooling effect in two ways. Most importantly, they are constantly drawing water up through their roots and bringing it in contact with the atmosphere through the stomata on their leaf surfaces. Here, liquid water molecules absorb heat and become water vapor. This process, called evapotranspiration (see Chapter 6), has a cooling effect on the surrounding environment. Vegetation also helps cool the urban environment by blocking sunlight that would otherwise strike roads and buildings and get absorbed as heat. Rooftop gardens have been singled out as being particularly effective in cooling the environment because they substitute cooling vegetation for a heat-absorbing surface at a location that usually receives sunlight throughout the day.
Building a Sustainable Green Space System in Bhubaneswar City, Odisha, Using Space Inputs
Published in Uday Chatterjee, Arindam Biswas, Jenia Mukherjee, Sushobhan Majumdar, Advances in Urbanism, Smart Cities, and Sustainability, 2022
Ashis Chandra Pathy, Gopal Krishna Panda
Urban green spaces supply to cities with ecosystem services ranging from maintenance of biodiversity to the regulation of urban climate. Comparing with rural areas, differences in solar input, rainfall pattern and temperature are usual in urban areas. Solar radiation, air temperature, wind speed and relative humidity vary significantly due to the built environment in cities. (Sadashivam and Tabassu, 2006). Urban heat island effect is caused by the large areas of heat absorbing surfaces, in combination of high energy use in cities. Urban heat island effect can increase urban temperatures by 5°C (Andrea, 2015).
Influence of meteorological factors on evaporative cooling of steel slag permeable concrete pavement
Published in International Journal of Pavement Engineering, 2022
Xudong Chen, Chaoguo Wu, Zhang Chen, Chen Chen, Chang Jin
In order to solve the urban heat island effect, several mitigation technologies have been developed, including the applications of advanced materials, atmospheric radiators, additional plants, and solar evaporative cooling systems (Akbari et al. 2016). Analysis of the performance of existing large-scale mitigation projects shows that the use of existing technologies can decrease the peak temperature of cities by 2.5–3°C (Santamouris et al. 2017). Permeable pavement containing numerous pores is one of the most effective technologies, which can not only save a lot of water, but also reduce pavement temperature by accelerating air circulation and evaporative cooling. The Essence of Evaporative Cooling in Permeable Pavement is the Heat and Moisture Transfer Process in Internal Pores (Kaffel et al. 2019), Moisture is transported through capillary force from saturated water area to evaporation surface for evaporation, with the continuous consumption of internal water, the saturated water content area gradually decreases, the water transfer resistance gradually increases, and the evaporative cooling effect will gradually decrease (Kuehni et al. 2016).
Climate change and extreme weather: A review focusing on the continental United States
Published in Journal of the Air & Waste Management Association, 2021
Cities are typically warmer than their surrounding regions, an effect denoted the urban heat island. Increased absorption of solar radiation, the absence of the cooling effect of vegetated surfaces and, to a lesser extent, the release of waste heat from human activities, all contribute to urban warmth (Taha 1997). At the same time, the relative humidity in cities is often lower than in their surroundings, a result of both the higher temperatures and the reduction in evapotranspiration from impermeable and unvegetated surfaces (Hass et al. 2016: Landsberg 1981). Higher temperatures, especially overnight, can cause morbidity and mortality associated with heat waves are to concentrate in urban areas. High overnight low temperatures contribute to the negative health outcomes in a heat wave by preventing people in unairconditioned dwellings from recovering overnight from the stress of daytime heat. An example, albeit one with likely little connection to climate change, is the July 1995 heat wave in the U.S. Midwest. Of the estimated 830 deaths, approximately 525 were in Chicago (Changnon, Kunkel, and Reinke 1996). The urban heat island of Chicago, where overnight low temperatures were 2 to 2.5°C warmer than in surrounding rural and suburban areas (Kunkel et al. 1996), may have contributed to the tragic outcomes of this heat wave in the city, though Changnon, Kunkel, and Reinke (1996) point out that the concentration vulnerable elderly people was also a factor.
Companion to public space
Published in Journal of Urban Design, 2021
In her chapter, Vania Ceccato discusses safety in public spaces from a place-oriented, public-health perspective. She considers both the negative consequences of crime concentrations in public spaces as well as the positive impacts of outdoor places on safety and health. In other chapters, additional health and safety topics are addressed, such as public open spaces for visually impaired people, security from terrorism, safety for older park users, and connections between equity and health. In addition to the pandemic, climate change should prompt us to reconsider outdoor public spaces. As the planet heats up, the urban heat island effect is exacerbated. These places grow hotter as a result of a lack of tree canopies and an abundance of asphalt paving. Urban heat islands occur disproportionately in poorer neighbourhoods and contribute to increases in air pollution and heat-related deaths and illnesses.