scholarly journals Features of the formation of urban heat islands effects in tropical climates and their impact on the ecology of the city

2019 ◽  
Vol 91 ◽  
pp. 05005 ◽  
Author(s):  
Minh Tuan Le ◽  
Nguyen Anh Quan Tran
Keyword(s):  
Urban Areas ◽  
Building Materials ◽  
Urban Landscape ◽  
Urban Climate ◽  
Ecological Systems ◽  
Urban Heat Islands ◽  
Heat Islands ◽  
Urban Heat ◽  
Tropical Climates ◽  
The City

The cumulative heating in some urban areas due to the urban growth and its types of industry, energy and transport, is the effect of urban heat island (UHI). It is recognized as one of the characteristics of the urban climate. The temperature increase caused by the effect (UHI) affects the energy flow in urban ecological systems, creates an unusual urban climate. By studying the effects of climate factors, local building materials to optimize energy efficiency, urban landscape, UHI phenomenon could be significantly moderated.

scholarly journals The Influence of Vegetation on UHIs, MUHIs, and Microclimate of Selected Southern Cities

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 509A-509
Author(s):  
Derald A. Harp ◽  
Edward L. McWilliams
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Building Materials ◽  
Urban Heat Islands ◽  
Shopping Malls ◽  
Heat Islands ◽  
Suburban Areas ◽  
Winter Temperatures ◽  
Urban Heat ◽  
The City

Urban areas have average annual temperatures 2–3°C warmer than surrounding rural areas, with daily differences of 5–6°C common. A suggested reason for this temperature difference is the extensive use of concrete, asphalt, and other building materials in the urban environment. Vegetation can moderate these temperatures by intercepting incoming radiation. The influence of vegetation patterns on the magnitude of urban and micro-urban “heat islands” (UHI and MUHI, respectively) is compared for several cities including Houston, Austin, College Station, and Ft. Worth, Texas; Huntsville, Ala.; and Gainesville, Fla. Temperatures for all cities studied were greatest in the built-up areas and dropped off in suburban areas and adjacent rural areas. In Houston, surrounding rice fields were 3–5°C cooler than urban areas. Heavily built-up areas of Austin were 2–4°C warmer than parks and fields outside of the city. In all of the cities, large parks were typically 2–3°C cooler than adjacent built-up areas. Large shopping malls varied in nocturnal winter and summer temperature, with winter temperatures near door openings 2–3°C warmer, and summer daytime temperatures as much as 17°C cooler beneath trees. This effect seemed to persist at the microclimatic scale. Areas beneath evergreen trees and shrubs were warmer in the winter than surrounding grass covered areas. Video thermography indicated that the lower surfaces of limbs in deciduous trees were warmer than the upper surfaces. Overall, vegetation played a significant role, both at the local and microscale, in temperature moderation.

scholarly journals IASI observations at the city scale

2020 ◽  
Author(s):  
Sarah Safieddine ◽  
Maya George ◽  
Cathy Clerbaux ◽  
Ana Paracho ◽  
Anne Boynard ◽  
...  
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Spatial Scales ◽  
Urban Heat Islands ◽  
Atmospheric Composition ◽  
Heat Islands ◽  
Large Cities ◽  
Urban Heat ◽  
Good Tracer ◽  
The City

<p>IASI is a versatile mission, allowing the measurement of both meteorological parameters such as temperature and atmospheric composition for infrared absorbing species. With its long observation record and frequent overpasses, IASI is able to follow changes at different spatial scales. We studied IASI’s capability to track the anthropogenic signature associated with large cities, both in terms of temperature fingerprint (urban heat islands) and carbon monoxide (CO) content, a good tracer of human activity (transport, heating, and industrial activities). For this study we averaged the IASI data available since the launch of the first IASI, in order to increase the signal to noise, and allow discriminating the city from its surroundings. For skin temperatures we show that some cities experience much warmer temperatures than nearby rural areas, with day and night differences, whereas other urban areas appear as cold urban islands when surrounded by deserts Examples will be shown and compare with MODIS observations. For CO emitted by human activities, we identified some cities that stand out from their background, and were able to compare their CO associated signatures with measurements provided by other available spaceborne instruments such as Mopitt and TROPOMI.</p>

scholarly journals High-Resolution Simulations of the Urban Thermal Climate in Suzhou City, China

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 118
Author(s):  
Yan Chen ◽  
Ning Zhang ◽  
Yan Zhu
Keyword(s):  
High Resolution ◽  
Urban Areas ◽  
Urban Climate ◽  
Urban Canopy ◽  
High Density ◽  
Urban Heat Islands ◽  
Medium Density ◽  
Heat Islands ◽  
Thermal Climate ◽  
Urban Heat

City thermal discomfort conditions have been exacerbated by the rapid urbanization processes in China. High-resolution urban thermal climate simulations can help us to understand urban climate features and produce better urban designs. In this paper, a single-layer urban canopy model (UCM) combined with Landsat satellite data and high-resolution meteorological forcing data was used to simulate very-high-resolution characteristics of temperature and humidity at the urban canopy level, and the heat index at the pedestrian level was also estimated. The research shows that the National center of environmental forecasting, Oregon state university, Air force and Hydrological research lab (NOAH)-UCM model can simulate the distribution of meteorological elements for different land uses in a fine and effective manner, making it an effective approach to obtaining the fundamental data for urban climate analysis. The spatial distribution pattern of urban heat islands in Suzhou is highly consistent with urban land cover fraction. High-density and medium-density urban areas are centers of urban heat islands, and the annual number of high-temperature days and heat indices over the high-density and medium-density urban areas are markedly higher than those in low-density cities and suburbs, indicating that urban development has a significant impact on the urban thermal environment.

scholarly journals Analysis of the urban heat island in representative points of the city of Bayeux / PB

2018 ◽  
Vol 7 (6) ◽  
pp. 345
Author(s):  
Amanda Mayara Paulino Da Silva
Keyword(s):  
Land Use ◽  
Urban Heat Island ◽  
Thermal Field ◽  
Urban Climate ◽  
Urban Heat Islands ◽  
Heat Island ◽  
Thermal Discomfort ◽  
Heat Islands ◽  
Urban Heat ◽  
The City

Abstrat Urban growth has generated several socio-environmental problems and has altered the quality of life of people living in these environments. Due to the disorderly growth of cities and the various forms of urban land use and occupation, changes in the thermal field of these areas have occurred and caused the formation of urban heat islands and thermal discomfort in urban environments. Thus, the need to understand the formation of heat islands in these areas and the study of their causes and consequences grows. Given this context, the present work intends to study the urban climate of the city of Bayeux / PB, specifically the urban thermal field, and the formation of heat islands. For the accomplishment of the research, initially a bibliographical survey of the subject in question was made. Subsequently experimental points of meteorological data collection (temperature and relative air humidity) were defined in the metropolitan area of the city of João Pessoa, specifically in the municipality of Bayeux / PB. These points were defined based on the different types of land use and cover in the study area. The following experimental points were defined: a point in the center of the city of Bayeux / PB, another point on the banks of the BR230 direction Bayeux, and a reference point in a remnant of Atlantic forest. To obtain the urban heat island the reference point was used as a parameter of the climatic conditions of a natural environment. The data of temperature and relative humidity were collected through thermometers (HOBO U-10), which were placed on steel tripods (1.5 meters high) and monitored at uninterrupted intervals of 1 and 1 hour during the dry period and rainy region. The analysis of the data points to the formation of urban heat islands in the two periods evaluated in the city of Bayeux / PB, being the center of the city, the most critical area with the most intense heat islands. The vegetative cover played a predominant role in the climatic mitigation of the experimental samples as well as the presence of precipitation. The areas with impermeable soil cover presented the largest heat islands and contributed to the thermal discomfort of the study area. Keywords: Urban Climate, Thermodynamic Field, Urban Heat Island.

scholarly journals Ilhas de calor urbano em cidade do semiárido nordestino

GeoTextos ◽  
2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Juliana Maria Oliveira Silva ◽  
Marcelo De Oliveira Moura ◽  
Vinicius Ferreira Luna
Keyword(s):  
Data Collection ◽  
Air Temperature ◽  
Urban Climate ◽  
Temperature Data ◽  
Urban Heat Islands ◽  
Heat Island ◽  
Heat Islands ◽  
Intensity Category ◽  
Urban Heat ◽  
The City

<p>A pesquisa pautou-se nas concepções do Sistema Clima Urbano de Monteiro (1976) e procurou identificar e mapear as ilhas de calor urbano na cidade do Crato-CE, em dois períodos sazonais do ano. Para isso, foram selecionados 10 pontos experimentais distribuídos em bairros na zona urbana da cidade, e aferiram-se dados de temperatura do ar com termohigrômetros instalados em abrigos meteorológicos durante os meses de abril (mês chuvoso) e outubro (mês seco). A partir da coleta de dados, a categoria predominante de intensidade das Ilhas de Calor intra e interurbana para a cidade do Crato foi o de ‘Média magnitude’. O horário que ocorre a maior intensidade da ilha de calor é pela tarde, 14h, com valores superiores a 5ºC de diferença de um local para o outro. Os bairros mais densamente ocupados e com baixa cobertura vegetal apresentaram os maiores valores de temperatura, enquanto que, nos que se localizam mais próximos da encosta da chapada e com vegetação mais densa, ocorreram as temperaturas mais amenas.</p><p>Abstract</p><p>URBAN HEAT ISLANDS IN CITY OF THE NORTHEAST SEMIARID</p><p>The research was based on the conceptions of the Monteiro Urban Climate System (1976) and sought to identify and map the urban heat islands in the city of Crato/ Ce in two seasonal periods of the year. For this, 10 experimental points were selected and distributed in neighborhoods in the urban area of the city and air temperature data was measured with thermohygrometers installed in meteorological shelters during the months of April (rainy month) and October (dry month). From the data collection, the predominant intensity category of the intra and interurban Heat Islands for the city of Crato was that of ‘Medium magnitude’. The time that occurs the greatest intensity of the heat island is in the afternoon, 14h, with values above 5ºC of difference from one place to another. The most densely occupied neighborhoods and with low vegetation cover had the highest temperature values, while those located closer to the slope of the plateau and with more dense vegetation, the milder temperatures occurred.</p>

scholarly journals The Impact of Green Roofs on the Parameters of the Environment in Urban Areas—Review

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 792 ◽  
Author(s):  
Dariusz Suszanowicz ◽  
Alicja Kolasa Więcek
Keyword(s):  
Urban Areas ◽  
Central And Eastern Europe ◽  
Single Case ◽  
Green Roofs ◽  
Urban Heat Islands ◽  
Heat Islands ◽  
Urban Heat ◽  
The Impact ◽  
The City

This study presents the results of a review of publications conducted by researchers in a variety of climates on the implementation of ‘green roofs’ and their impact on the urban environment. Features of green roofs in urban areas have been characterized by a particular emphasis on: Filtration of air pollutants and oxygen production, reduction of rainwater volume discharged from roof surfaces, reduction of so-called ‘urban heat islands’, as well as improvements to roof surface insulation (including noise reduction properties). The review of the publications confirmed the necessity to conduct research to determine the coefficients of the impact of green roofs on the environment in the city centers of Central and Eastern Europe. The results presented by different authors (most often based on a single case study) differ significantly from each other, which does not allow us to choose universal coefficients for all the parameters of the green roof’s impact on the environment. The work also includes analysis of structural recommendations for the future model green roof study, which will enable pilot research into the influence of green roofs on the environment in urban agglomerations and proposes different kinds of plants for different kinds of roofs, respectively.

scholarly journals A Review of How Building Mitigates the Urban Heat Island in Indonesia and Tropical Cities

Earth ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 653-666
Author(s):  
Dany Perwita Sari
Keyword(s):  
Urban Planning ◽  
Urban Areas ◽  
Tropical Climate ◽  
Urban Heat Islands ◽  
Weather Data ◽  
Adaptation Measures ◽  
Heat Islands ◽  
Tropical Cities ◽  
Urban Heat ◽  
Tropical Climates

A consequence of urbanization was the intensification of urban heat islands, especially in tropical cities. There have been rapid developments in infrastructure that have displaced open spaces. Meanwhile, Indonesia has a tropical climate directly affected by climate change. A high priority has been placed on adaptation measures to address issues such as sea-level rise, increased extreme weather, and threats to ecosystems and biodiversity. There is still a lack of specific knowledge regarding tropical climate in urban areas. In this paper, the author examines how building and urban planning affect urban heat islands in the tropics. According to the review, early planning and building based on local weather data can reduce the energy consumption and minimize the UHI effect. Furthermore, a media campaign and early education should increase awareness about adaptation measures between governments and citizens. Based on the findings from this study, some recommendations are offered for future urban planning, especially for tropical climates, to reduce UHI effects.

scholarly journals Urban heat island in Bloemfontein during winter

2013 ◽  
Vol 32 (1) ◽  
Author(s):  
Pieter Snyman ◽  
A. Stephen Steyn
Keyword(s):  
Maximum Intensity ◽  
Urban Heat Islands ◽  
Urban Air ◽  
Heat Island ◽  
Heat Islands ◽  
Air Temperatures ◽  
Local Topography ◽  
Urban Heat ◽  
The Difference ◽  
The City

Urban heat islands (UHIs) are characterised by warmer urban air temperatures compared to rural air temperatures, and the intensity is equal to the difference between the two. Air temperatures are measured at various sites across the city of Bloemfontein and then analysed to determine the UHI characteristics. The UHI is found to have a horseshoe shape and reaches a maximum intensity of 8.2 °C at 22:00. The UHI is largely affected by the local topography.

Estimating the expansion of urban areas and urban heat islands (UHI) in Ghana: a case study

2020 ◽  
Author(s):  
Isaac Buo ◽  
Valentina Sagris ◽  
Iuliia Burdun ◽  
Evelyn Uuemaa
Keyword(s):  
Urban Areas ◽  
Urban Heat Islands ◽  
Heat Islands ◽  
Urban Heat

scholarly journals Night Thermal Unmixing for the Study of Microscale Surface Urban Heat Islands with TRISHNA-Like Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1449 ◽  
Author(s):  
Carlos Granero-Belinchon ◽  
Aurelie Michel ◽  
Jean-Pierre Lagouarde ◽  
Jose A. Sobrino ◽  
Xavier Briottet
Keyword(s):  
Surface Temperature ◽  
Land Surface ◽  
Image Resolution ◽  
Urban Heat Islands ◽  
Land Uses ◽  
Regression Kriging ◽  
Heat Islands ◽  
Urban Heat ◽  
Land Covers ◽  
The City

Urban Heat Islands (UHIs) at the surface and canopy levels are major issues in urban planification and development. For this reason, the comprehension and quantification of the influence that the different land-uses/land-covers have on UHIs is of particular importance. In order to perform a detailed thermal characterisation of the city, measures covering the whole scenario (city and surroundings) and with a recurrent revisit are needed. In addition, a resolution of tens of meters is needed to characterise the urban heterogeneities. Spaceborne remote sensing meets the first and the second requirements but the Land Surface Temperature (LST) resolutions remain too rough compared to the urban object scale. Thermal unmixing techniques have been developed in recent years, allowing LST images during day at the desired scales. However, while LST gives information of surface urban heat islands (SUHIs), canopy UHIs and SUHIs are more correlated during the night, hence the development of thermal unmixing methods for night LSTs is necessary. This article proposes to adapt four empirical unmixing methods of the literature, Disaggregation of radiometric surface Temperature (DisTrad), High-resolution Urban Thermal Sharpener (HUTS), Area-To-Point Regression Kriging (ATPRK), and Adaptive Area-To-Point Regression Kriging (AATPRK), to unmix night LSTs. These methods are based on given relationships between LST and reflective indices, and on invariance hypotheses of these relationships across resolutions. Then, a comparative study of the performances of the different techniques is carried out on TRISHNA synthesized images of Madrid. Since TRISHNA is a mission in preparation, the synthesis of the images has been done according to the planned specification of the satellite and from initial Aircraft Hyperspectral Scanner (AHS) data of the city obtained during the DESIREX 2008 capaign. Thus, the coarse initial resolution is 60 m and the finer post-unmixing one is 20 m. In this article, we show that: (1) AATPRK is the most performant unmixing technique when applied on night LST, with the other three techniques being undesirable for night applications at TRISHNA resolutions. This can be explained by the local application of AATPRK. (2) ATPRK and DisTrad do not improve significantly the LST image resolution. (3) HUTS, which depends on albedo measures, misestimates the LST, leading to the worst temperature unmixing. (4) The two main factors explaining the obtained performances are the local/global application of the method and the reflective indices used in the LST-index relationship.

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