The Influence of NIR Pigments on Coil Coatings’ Thermal Behaviors

The effect of over-heating in urban areas, called the urban heat island effect (UHI effect), is responsible for greater energy consumption for cooling buildings. Several reflective near-infrared (NIR) coatings, called cool coatings have proved to be effective for contrasting the UHI effect. The thermal and appearance properties of cool coatings depend on the color and they often have been studied only at the initial state, without undergoing atmospheric degradation and soiling. In this work, the thermal, visual and durability behaviors of red and brown polyester-based organic coatings for roof applications were studied. All samples were subjected to accelerated degradation cycles composed of UV-B and salt spray chamber exposure. The sample degradation was assessed by infrared spectroscopy, gloss and colorimetric analyses. Moreover, the thermal behavior was studied by means of a simplified experimental setup. Finally, a soiling and weathering test was conducted to simulate the soiling of three years’ external exposure. Despite the phenomena of chemical degradation and a decrease in aesthetic properties, the samples maintain their thermal performance, which is not even influenced by dirt products. In addition, NIR pigments significantly improve the thermal behavior of brown coatings.

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Emergence of opposite trends in daytime and night-time urban heat island intensities in England

10.5194/egusphere-egu2020-5671 ◽

2020 ◽

Author(s):

Eunice Lo ◽

Dann Mitchell ◽

Sylvia Bohnenstengel ◽

Mat Collins ◽

Ed Hawkins ◽

...

Keyword(s):

Urban Heat Island ◽

Urban Areas ◽

Urban Land Use ◽

Urban Heat Islands ◽

Urban Heat Island Effect ◽

Heat Island ◽

Night Time ◽

Heat Islands ◽

Island Effect ◽

Urban Heat

<p>Urban environments are known to be warmer than their sub-urban or rural surroundings, particularly at night. In summer, urban heat islands exacerbate the occurrence of extreme heat events, posing health risks to urban residents. In the UK where 90% of the population is projected to live in urban areas by 2050, projecting changes in urban heat islands in a warming climate is essential to adaptation and urban planning.</p><p>With the use of the new UK Climate Projections (UKCP18) in which urban land use is constant, I will show that both summer urban and sub-urban temperatures are projected to increase in the 10 most populous built-up areas in England between 1980 and 2080. However, differential warming rates in urban and sub-urban areas, and during day and at night suggest a trend towards a reduced daytime urban heat island effect but an enhanced night-time urban heat island effect. These changes in urban heat islands have implications on thermal comfort and local atmospheric circulations that impact the dispersion of air pollutants. I will further demonstrate that the opposite trends in daytime and night-time urban heat island effects are projected to emerge from current variability in more than half of the studied cities below a global mean warming of 3&#176;C above pre-industrial levels.</p>

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CLIMATE-ORIENTED ASSESSMENT OF MAIN STREET DESIGN AND DEVELOPMENT IN BUDAPEST

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2016.1185431 ◽

2016 ◽

Vol 24 (4) ◽

pp. 258-268 ◽

Cited By ~ 7

Author(s):

Maria CSETE ◽

Attila BUZASI

Keyword(s):

Urban Areas ◽

Assessment Tool ◽

Runoff Water ◽

Street Design ◽

Urban Street ◽

Weather Patterns ◽

Island Effect ◽

Urban Heat ◽

Planning And Construction ◽

Main Streets

Main streets play pivotal role in urban areas in terms of economic, social, moreover environmental contexts. Such streets are generally situated in densely built-up areas, where the adverse effects of climate change, such as rising temperature and changing precipitation patterns occur emphatically. Increasing urban heat island effect or extreme amount of runoff water during severe storms and floods significantly decrease the adaptive capacity of a city, consequently its residents becoming more vulnerable. Therefore involving climate-oriented design principles into planning and construction phase contributes to reach more sustainable and climate-friendly open spaces what are strongly relevant especially in main streets which are designed for a great amount of people. Present study provides a criteria matrix for assessing the climate-friendly level of recently renewed main streets in Budapest. Due to this assessment tool the adaptation and mitigation performance of the selected projects can be evaluated. For identifying strengths and weaknesses of a given project, a rating scheme has been applied by selecting and using 42 indicators grouped into mitigation, adaptation and awareness raising categories. Thus planners, decision-makers and other stakeholders can easily define future opportunities and challenges, accordingly this study may contribute to take urban street design practices toward climate-friendliness by paying more attention on changing local weather patterns and related consequences.

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Data and techniques for studying the urban heat island effect in Johannesburg

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-7-w3-203-2015 ◽

2015 ◽

Vol XL-7/W3 ◽

pp. 203-206 ◽

Cited By ~ 3

Author(s):

C. H. Hardy ◽

A. L. Nel

Keyword(s):

Remote Sensing ◽

Urban Heat Island ◽

Urban Areas ◽

Remote Sensing Data ◽

Urban Heat Island Effect ◽

Heat Island ◽

Sensing Data ◽

Island Effect ◽

Urban Heat ◽

The City

The city of Johannesburg contains over 10 million trees and is often referred to as an urban forest. The intra-urban spatial variability of the levels of vegetation across Johannesburg’s residential regions has an influence on the urban heat island effect within the city. Residential areas with high levels of vegetation benefit from cooling due to evapo-transpirative processes and thus exhibit weaker heat island effects; while their impoverished counterparts are not so fortunate. The urban heat island effect describes a phenomenon where some urban areas exhibit temperatures that are warmer than that of surrounding areas. The factors influencing the urban heat island effect include the high density of people and buildings and low levels of vegetative cover within populated urban areas. This paper describes the remote sensing data sets and the processing techniques employed to study the heat island effect within Johannesburg. In particular we consider the use of multi-sensorial multi-temporal remote sensing data towards a predictive model, based on the analysis of influencing factors.

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How effective is ‘greening’ of urban areas in reducing human exposure to ground-level ozone concentrations, UV exposure and the ‘urban heat island effect’? An updated systematic review

Environmental Evidence ◽

10.1186/s13750-021-00226-y ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Teri Knight ◽

Sian Price ◽

Diana Bowler ◽

Amy Hookway ◽

Sian King ◽

...

Keyword(s):

Urban Heat Island ◽

Urban Areas ◽

Ground Level ◽

Urban Heat Island Effect ◽

Heat Island ◽

Ground Level Ozone ◽

Ozone Concentrations ◽

Island Effect ◽

Green Areas ◽

Urban Heat

Abstract Background This review updates a systematic review published in 2010 (http://www.environmentalevidence.org/completed-reviews/how-effective-is-greening-of-urban-areas-in-reducing-human-exposure-to-ground-level-ozone-concentrations-uv-exposure-and-the-urban-heat-island-effect) which addressed the question: How effective is ‘greening’ of urban areas in reducing human exposure to ground-level ozone concentrations, UV exposure and the ‘urban heat island effect’? Methods Searches of multiple databases and journals for relevant published articles and grey literature were conducted. Organisational websites were searched for unpublished articles. Eligibility criteria were applied at title, abstract and full text and included studies were critically appraised. Consistency checks of these processes were undertaken. Pre-defined data items were extracted from included studies. Quantitative synthesis was performed through meta-analysis and narrative synthesis was undertaken. Review findings 308 studies were included in this review. Studies were spread across all continents and climate zones except polar but were mainly concentrated in Europe and temperate regions. Most studies reported on the impact of urban greening on temperature with fewer studies reporting data on ground-level UV radiation, ozone concentrations (or precursors) or public health indicators. The findings of the original review were confirmed; urban green areas tended to be cooler than urban non-green areas. Air temperature under trees was on average 0.8 °C cooler but treed areas could be warmer at night. Cooling effect showed tree species variation. Tree canopy shading was a significant effect modifier associated with attenuation of solar radiation during the day. Urban forests were on average 1.6 °C cooler than comparator areas. Treed areas and parks and gardens were associated with improved human thermal comfort. Park or garden cooling effect was on average 0.8 °C and trees were a significant influence on this during the day. Park or garden cooling effect extended up to 1.25 kms beyond their boundaries. Grassy areas were cooler than non-green comparators, both during daytime and at night, by on average 0.6 °C. Green roofs and walls showed surface temperature cooling effect (2 and 1.8 °C on average respectively) which was influenced by substrate water content, plant density and cover. Ground-level concentrations of nitrogen oxides were on average lower by 1.0 standard deviation units in green areas, with tree species variation in removal of these pollutants and emission of biogenic volatile organic compounds (precursors of ozone). No clear impact of green areas on ground level ozone concentrations was identified. Conclusions Design of urban green areas may need to strike a balance between maximising tree canopy shading for day-time thermal comfort and enabling night-time cooling from open grassy areas. Choice of tree species needs to be guided by evapotranspiration potential, removal of nitrogen oxides and emission of biogenic volatile organic compounds. Choice of plant species and substrate composition for green roofs and walls needs to be tailored to local thermal comfort needs for optimal effect. Future research should, using robust study design, address identified evidence gaps and evaluate optimal design of urban green areas for specific circumstances, such as mitigating day or night-time urban heat island effect, availability of sustainable irrigation or optimal density and distribution of green areas. Future evidence synthesis should focus on optimal design of urban green areas for public health benefit.

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The urban heat island effect is closely related to cicada density in metropolitan Seoul

10.7287/peerj.preprints.3064v1 ◽

2017 ◽

Author(s):

Hoa Q. Nguyen ◽

Yuseob Kim ◽

Yikweon Jang

Keyword(s):

Urban Heat Island ◽

Rural Areas ◽

Urban Areas ◽

Underlying Mechanism ◽

Heat Island ◽

Population Densities ◽

Island Effect ◽

Significant Difference ◽

Order Of Magnitude ◽

Urban Heat

Background. Cryptotympana atrata and Hyalessa fuscata are the most abundant cicada species in the Korean Peninsula, where their population densities are higher in urban areas than in rural ones. The urban heat island (UHI) effect, wherein human activities cause urban areas to be significantly warmer than surrounding rural areas, may underlie this difference. We predicted a positive relationship between the degrees of UHI in urban areas and population densities of C. atrata and H. fuscata. Methods. To test this prediction, we examined cicada population densities in three groups: those of high and low UHI areas within metropolitan Seoul, and suburban areas. Enumeration surveys of cicada exuviae were conducted from July to August, 2015. Results. C. atrata and H. fuscata constituted almost 30% and 70% of the cicada populations, respectively, collected across all sampling localities. No significant difference in species composition was observed, regardless of groups, but the densities of the two species were significantly higher in urban areas with high UHI than in other groups. Specifically, densities of C. atrata in high UHI areas were approximately seven and four times higher compared to those in low UHI and in suburban groups, respectively. The order of magnitude was greater in H. fuscata, where densities in high UHI group were respectively 22 and six times higher than those in low UHI and in suburban groups. Discussion. These results suggest that the UHI effect may be closely linked to high cicada densities in metropolitan Seoul, although the underlying mechanism for this remains unclear.

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Research on spatial characteristics of metropolis development using nighttime light data: NTL based spatial characteristics of Beijing

PLoS ONE ◽

10.1371/journal.pone.0242663 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0242663

Author(s):

Yuli Yang ◽

Mingguo Ma ◽

Xiaobo Zhu ◽

Wei Ge

Keyword(s):

Urban Areas ◽

Urban Land Use ◽

Rapid Urbanization ◽

Spatial Characteristics ◽

Spatial And Temporal Scales ◽

Island Effect ◽

Nighttime Light Data ◽

Nighttime Light ◽

Urban Heat ◽

Research Period

As the capital and one of the metropolises in China, Beijing has met with a number of serious so-called "urban diseases" in the process of rapid urbanization such as blind expansion of urban areas, explosion of population and the increase of urban heat island effect. To treat these “urban diseases” and make the metropolis develop healthful and sustainable in Beijing in the future, the spatial characteristics of metropolis developments in Beijing are explored in this paper. The urban built-up areas in Beijing are extracted using the DMSP-OLS nighttime light data from 1992 to 2013. The characteristics of the urban developments of Beijing are studied, including spatial and temporal scales of urban developments, urban barycenter of Beijing and its transfer trajectory, variations of urban spatial forms and the differences of urban internal developments. The results have shown that the built-up areas had been increasing and circling extending from the central urban areas to the outer spaces in the last 21 years. The built-up area had expanded by 878km2 in 1992–2013, and the built-up area in 2013 had expanded to three times comparing to that of 1992. The expanding area of the built-up area in the northeast is the largest. The expansion of the urban had mainly occurred in 1996–2007, and the expanded area had accounted for 92% of the total research period. During the whole research period, the urban barycenter of Beijing had moved 5000.71 meters towards Northeast 28° of its original place from Dongcheng District to Chaoyang District. The development level of each municipal district had been increasing year by year, and the development differences among the municipal districts had been gradually reduced; the spatial forms of Beijing had been alternately changed between extensive and intensive expansion. The results of this study can help to plan urban land use and people migration of Beijing.

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Synthetic Aggregates for the Production of Innovative Low Impact Porous Layers for Urban Pavements

Infrastructures ◽

10.3390/infrastructures4030048 ◽

2019 ◽

Vol 4 (3) ◽

pp. 48 ◽

Cited By ~ 6

Author(s):

Piergiorgio Tataranni ◽

Cesare Sangiorgi

Keyword(s):

Urban Areas ◽

Water Infiltration ◽

Alkali Activation ◽

Porous Asphalt ◽

Porous Layers ◽

Island Effect ◽

Viable Solution ◽

Urban Heat ◽

The One ◽

Control And Management

According to the latest estimates, 40% of urban areas are covered by pavements. One of the most remarkable effects on the urban environment is the increase in impermeable surfaces which leads to problems related to water infiltration into the ground and the increase in wash-off volumes. The use of permeable and porous layers in urban applications for cycle lanes, footpaths and parking areas is growing in interest, increasing the potential for control and management of urban runoff. In this paper, a physical and mechanical characterization is proposed of an innovative mixture, prepared with a polymeric transparent binder for semi-porous layers with reduced contribution to the urban heat island effect. Two versions of this mixture are compared, one with just virgin and the one with artificial synthetic aggregates, produced through the alkali-activation of waste basalt powder. Results show suitable properties for both materials if compared to porous asphalt concretes in traditional pavements. Furthermore, the application of synthetic aggregates seems to be a viable solution for the production of innovative and eco-friendly mixtures, allowing the recycling of waste materials.

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Flood Risk Mapping for Different Landuse Senarios Based on RS and GIS

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.2415 ◽

2013 ◽

Vol 295-298 ◽

pp. 2415-2419

Author(s):

Jian Fen Liu ◽

Xing Nan Zhang ◽

Hui Ming Wang

Keyword(s):

Flood Risk ◽

Urban Areas ◽

Public Infrastructure ◽

Island Effect ◽

Influencing Mechanism ◽

Rs And Gis ◽

Risk Increase ◽

Urban Heat ◽

Urbanized Areas ◽

Flood Risk Mapping

Beginning from the study on influencing mechanism of urbanization on flood risk, various influencing indicators of flood risk in urbanized areas are researched, presenting that the change of land use, lagged underground drainage, urban heat island effect, accumulative population, wealth and public infrastructure which make cities——the hazard bearing bodies more vulnerable and flood risk increase as well. Supported by RS and GIS, taking Changzhou as an example, the indicators of urbanization shown by two landuse type maps extracted from TM in 2001 and 2008 on flood risk are analyzed together with DEM and distance to discharge channel, it found that urbanized degree and flood risk are a positive correlation, flood risk in more highly urbanized areas is greater, as a consequence of vulnerability and exposure of urban areas increasing.

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Can Cities Activate Sleeper Species and Predict Future Forest Pests? A Case Study of Scale Insects

Insects ◽

10.3390/insects11030142 ◽

2020 ◽

Vol 11 (3) ◽

pp. 142 ◽

Cited By ~ 2

Author(s):

Steven D. Frank ◽

Michael G. Just

Keyword(s):

Urban Heat Island ◽

Urban Areas ◽

Egg Production ◽

Urban Trees ◽

Scale Insects ◽

Urban Heat Island Effect ◽

Heat Island ◽

Island Effect ◽

The Us ◽

Urban Heat

Sleeper species are innocuous native or naturalized species that exhibit invasive characteristics and become pests in response to environmental change. Climate warming is expected to increase arthropod damage in forests, in part, by transforming innocuous herbivores into severe pests: awakening sleeper species. Urban areas are warmer than natural areas due to the urban heat island effect and so the trees and pests in cities already experience temperatures predicted to occur in 50–100 years. We posit that arthropod species that become pests of urban trees are those that benefit from warming and thus should be monitored as potential sleeper species in forests. We illustrate this with two case studies of scale insects that are important pests of urban trees in parts of the US. Melanaspis tenebricosa and Parthenolecanium quercifex are geographically native to the US but take on invasive characteristics such as higher survival and reproduction and become disconnected from natural enemies on urban trees due to the urban heat island effect. This allows them to reach high densities and damage their host trees. Parthenolecanium quercifex density increases up to 12 times on urban willow oaks with just 2 °C of warming due to higher survival and adaptation to warmer temperatures. The urban heat island effect also creates a phenological mismatch between P. quercifex and its parasitoid complex, and so egg production is higher. Melanaspis tenebricosa density can increase 300 times on urban red maples with 2.5 °C of warming. This too is due to direct effects of warmer temperatures on survival and fecundity but M. tenebricosa also benefits from the drought stress incurred by warmer urban trees. These effects combine to increase M. tenebricosa density in forests as well as on urban trees at latitudes higher than its native range. We illustrate how cities provide a unique opportunity to study the complex effects of warming on insect herbivores. Studying pestilent urban species could be a pragmatic approach for identifying and preparing for sleeper species.

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Efficiency, economics, and the urban heat island

Environment and Urbanization ◽

10.1177/0956247816655676 ◽

2016 ◽

Vol 29 (1) ◽

pp. 183-194 ◽

Cited By ~ 3

Author(s):

Mark J Miner ◽

Robert A Taylor ◽

Cassandra Jones ◽

Patrick E Phelan

Keyword(s):

Urban Heat Island ◽

Urban Areas ◽

Global Perspective ◽

Effect Of Temperature ◽

Marginal Effect ◽

Heat Island ◽

Middle Income ◽

Island Effect ◽

Urban Heat

Economic and societal costs of the urban heat island are considered through the marginal effect of temperature increase on device efficiency and lifespan. Urbanization is virtually synonymous with the mechanization of human comfort systems, and the efficiency of these systems is subject to degradation from the urban heat island. The simplest way to model this degradation is an application of ideal device efficiencies, and the results of such an analysis are presented and considered in this paper. The magnitude of these costs and their avoidance or potential mitigation avenues are the principal topics of the work, and the technical underpinnings of the approach are presented in supplementary material available online. The self-reinforcing nature and economic scale of the urban heat island effect are thus approached from the first principles of thermodynamics and available data on relevant devices and systems. A global perspective on the phenomenon is presented, followed by a case study of the Phoenix, Arizona (US) metropolitan area to demonstrate the scale of these effects. This analysis synthesizes thermodynamic and economic approaches to the health and policy issues of the urban heat island, with particular consideration given to planning for minimization of these effects in low- and middle-income urban areas. This study first estimates the costs borne today by large urban centres, then highlights some of the risks that secondary cities will eventually face – and could potentially mitigate – as they undergo rapid growth and densification.

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