Aug 03, 20 urban heat island effect, how is it calculated and taken into account in temperature recording. Urban heat islands areas of heat intensified by built environments affect nearly every urbanized area and that populations that live in them. A citys high building density and paved surfaces cause it to retain more heat than open, natural areas. Urban heat islands are also common over the cities of even fairly small size. Urban heat island is a major problem associated with rapid urbanisation. Strong winds reduce the temperature contrast by mixing together the city and rural air. Pdf the urban heat island phenomenon modelling and analysis. An urban heat island uhi is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. Minimizing urban heat island effect and imperviousness factor in bangalore d e v s kiran kumar research associate sustainable habitat division the energy and resources institute teri, india. This fact is known as the urban heat island effect.
The route through montreal was designed to include the core of its heat island based on previous work oke and. Can raise temperatures over cities 1 to more than 10 degrees f over that of surrounding areas. It defines and examines the characteristics of the urban heat island, and scientifically assigns a score based on atmospheric modeling for each census tract in and around most urban. This paper presents a simulation model, which was incorporated into a geographic information system gis, in order to calculate the maximum. Topics covered include the effects of urbanization on average temperature and strategies to mitigate temperature increases. Therefore these maps do not reflect the total heat in each area, just the increase in temperature that is due to the urban heat island itself. Cool paving and roofing materials along with an expansion of the citys urban forest. Landsat collects reflected thermal infrared measurements and converts the data into digital files. Linking science to april 2004 urban heat island and climate. Heat is created by energy from all the people, cars, buses, and trains in big cities like new york, paris, and london. Its common in cities across the nation but its advancing in louisville at one of the fastest rates in the. Then, according to the okes heat island parametric model that shows that. In 2015, calepa released a study entitled creating and mapping an urban heat island index for california pdf.
The urban heat island effects can also be reduced by weather phenomona. We present evidence of a significant urban heat island uhi effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal nighttime and maximal daytime air temperature in the yrdua using 41 meteorological stations observation. Researchers typically measure air temperatures through a dense network of. Planning urban heat island mitigation in boston erin coutts kate ito cecilia nardi trang vuong tufts university urban and environmental policy and planning. Colors are assigned to the data to show relative thermal energy. What links here related changes upload file special pages permanent link page information wikidata item cite this page. Urban heat islands are created in areas like these. The properties of urban roofs and pavements, as well as human activity, contribute to the formation of summer noglossaryurban heat islandsno. This urban heat island map was produced using londum, a specific setup of the met office unified model version 6. The european space agencys center for earth observation known as esrin has been looking out how thermal radiation modeling using satellite sensors can be used to predict urban heat islands. What factors appear to affect the urban heat island. Urban heat island water sustainability and climate. If the downtown area is newark, nj, where would wyckoff, nj, be on the diagram. Song d x and zheng k j 2016 research on urban heatisland effect proc.
The clearer the sky the greater is the development of the city temperature. The effect of urban heat island on climate warming in the. An urban heat island study for building and urban design. An urban heat island, or uhi, is a metropolitan area thats a lot warmer than the rural areas surrounding it.
In 2015, calepa released a study entitled, creating and mapping an urban heat island index for california 5 mb, pdf. Aug 21, 2014 a report by climate central ranks washington d. An urban heat island study for building and urban design a thesis submitted to the university of manchester for the degree of doctor of philosophy in the faculty of engineering and physical sciences 2011 henry kei wang cheung school of mechanical, aerospace and civil engineering. A statistical model for the urban heat island and its. In 2015, calepa released a study entitled, creating and mapping an urban heat island index for california pdf download 5 mb, pdf. The highest values of the urban heat island intensity, in the region of 38 c, are often reached between about 11 oclock at night and 3 oclock in the morning figure 2. Potential of urban densification to mitigate the effects of heat island.
A gis extension model to calculate urban heat island intensity based on urban geometry. The temperature increase is attributed to deforestation and the. The urban heat island uhi is the phenomenon where temperatures are relatively higher in cities compared to surrounding rural areas due to, for example, the urban surfaces and anthropogenic heat sources. Urban heat island effect, how is it calculated and taken into. Jul 27, 2015 we present evidence of a significant urban heat island uhi effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal nighttime and maximal daytime air temperature in the yrdua using 41 meteorological stations observation. Summary report urban heat island effect preface this report discusses issues and policies related to the urban heat island uhi. The standard mm5 input files for the land surface module i. The project consisted of two parts, one focusing on the analysis of the urban heat island phenomenon in the greater camden region, the other focusing on mitigation strategies for the urban heat. Mapping manchesters urban heat island sylvia knight1, claire smith2 and michael roberts3 1royal meteorological society, reading 2university of manchester 3altrincham grammar school for girls, cheshire introduction an urban heat island uhi is a phenomenon whereby urban areas experience elevated temperatures relative to the surrounding. The information contained in this toolkit is intended for reference purposes only. Minimizing urban heat island effect and imperviousness factor. This temperature difference usually is larger at night than.
Urban heat islands uhis, usually defined as temperature differences between urban areas and their surrounding rural areas, are one of the most significant anthropogenic modifications to the earths climate. Aug 07, 2019 urban inhabitants also suffer during heat waves because the urban heat island prevents nighttime temperatures from decreasing as they do in rural areas. A linear statistical model relating the nocturnal urban heat island uhi intensity of hamburg with meteorological conditions is constructed from observations taken by the german meteorological service dwd. The simplest is to compare historical temperature records for an urban area with the surrounding rural areas. Linking science to april 2004 urban heat island and. May 18, 2016 urban heat islands uhis, usually defined as temperature differences between urban areas and their surrounding rural areas, are one of the most significant anthropogenic modifications to the earths climate. Urban planning characteristics to mitigate climate change in. The urban heat island phenomenon modelling and analysis as an. Is the temperature of the surrounding countryside taken into account. Scroll over the image to view aerial photos of the northern new jerseynew york city region. White areas are around 160f 70c, while dark blue areas are near 85f 30c. Table 31 characteristics of surface and atmospheric urban heat islands 3. Economic assessment of the urban heat island effect.
Urban heat islands, albedo modeling, uhi amplification effects, global warming causes and amplification 7 effects, uhi footprint, uhi heat dome, cool roofs, sea ice and moisture feedbacks. Thus, this paper investigates the primary factors of urban heat island formation, such as population, which significantly affects energy consumption. Summary report urban heat island effect cool roofs and. Pdf the modeling of the urban microclimate, in particular the phenomenon of. Heat islands can occur yearround during the day or night. Ppt urban heat island effect powerpoint presentation. This phenomenon is known as an urban heat island and the contrast can most notably be measured at night. Pdf urban heat island towards urban climate researchgate. This initial planting on the south bank will be followed by other similartype plantings and will ultimately lead to a complete vegetation covering of this part of the parc. Compendium of strategies describes the causes and impacts of summertime urban heat islands and promotes strategies for lowering temperatures in u. Heat islands are zones of relative warmth created by urban air and surface temperatures that are higher than those of. The temperature difference between the city and surrounding areas is also a function of winds. Effects of urban heat island on air pollution concentrations.
Currently, the energy sustainability codes in india recommends about cool roofs at building level to. Minimizing urban heat island effect and imperviousness. Most of the cities in south asia face deficit in energy supply as the gap between demand and supply go up during summers. Compendium of strategies describes the causes and impacts of summertime urban heat islands and promotes strategies. When talking about urban heat islands uhi basically 3 boundaries of measurement need to also understand areas in which the temperature is being measured. Ozone can inflame the respiratory tract and increase the lungs susceptibility to infections, allergens, and other air pollutants. Chapter 2 urban heat island gold standard and urban heat. Apr 14, 2017 urban heat islands areas of heat intensified by built environments affect nearly every urbanized area and that populations that live in them. The project consisted of two parts, one focusing on the analysis of the urban heat island phenomenon in the greater camden region, the other. It thus constitutes a reference document for the implementation of local demonstration projects on urban heat island mitigation, for which calls for proposals are. Extreme temperatures lead to heat cramps, heatstroke, and heat. The increased heat of our cities increases discomfort for everyone, requires an increase in the amount of energy used for cooling purposes, and increases pollution. Urban areas become significantly warmer than surrounding areas when there is less green cover and more hard surfaces which absorb, store and radiate heat. Arifwidodo, department of landscape architecture, kasetsart university, bangkok, thailand, sigit.
Urban heat island effect, how is it calculated and taken. The weaker the wind velocity, the greater the heat island. There are several ways to determine how significant the urban heat island effect is. Another is to measure the heat escaping from an urban area and compare it to rural areas, this can be done via satellite, weather balloons or planes. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. It defines and examines the characteristics of the urban heat island and, for the first time, creates an urban heat island index to quantify the. Systems sustaina slideshare uses cookies to improve functionality and performance, and to. Research has found that urban heat islands not only increase temperatures during heat waves but also prolong their duration. In general when referencing uhi, the areas of interest are the surface heat island and canopy layer heat island. Note the warmer urban surface temperatures left side of image and cooler. It defines and examines the characteristics of the urban heat island and, for the first time, creates an urban heat island index to quantify the extent and severity of urban heat islands for individual cities. Surface urban heat island this image, taken from an aircraft, depicts a midday surface urban heat island in salt lake city, utah, on july, 1998. A free powerpoint ppt presentation displayed as a flash slide show on id. Planning urban heat island mitigation in boston prepared for.
Higher temperatures attributed to the urban heat island effect increase the likelihood of nox and vocs forming smog, which has serious health consequences. Aecom economic assessment of the urban heat island effect 14 november 2012 economic assessment of the urban heat island effect prepared for city of melbourne prepared by aecom australia pty ltd level 9, 8 exhibition street, melbourne vic 3000, australia. Keywords urban heat island mitigation, energy demand, costbenefit analysis, mm5. Urban heat island mitigation strategy toolkit created for the city of toronto by ec2 this toolkit has been created to provide a quick overview of different urban heat island mitigation strategies. Each citys urban heat island varies based on the city structure and thus the range of temperatures within the island vary as well. The temperature of urban areas can be significantly higher than that of the surrounding rural areas.
No, this is a separate phenomenon where cities are 6. An urban heat island uhi is a metropolitan area which is significantly warmer than its surroundings. The term urban heat island describes this phenomenon. Sep 29, 2011 this phenomenon is known as an urban heat island and the contrast can most notably be measured at night.
Waste heat from vehicles, factories, and air conditioners may add warmth to their surroundings, further exacerbating the heat island effect. Systems sustaina slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Included are policies to mitigate the urban heat island effect, improve storm water management within the city, reduce smog, expand the absorption capacity of floodplains and allow the restoration and rehabilitation of trinity river riparian corridors. Understanding urban heat island effect and its implications to climate change adaptation strategies in major southeast asian cities the following collaborators worked on this project.
This study applies the extreme value theory to model and detect trends in extreme uhi events in hong kong, which have rarely been documented. On an annual mean basis, air temperatures in large cities might be 1. The most striking characteristic of an urban microclimate is the urban heat island uhi effect. Pdf the urban heat island uhi is defined as the temperature. Urban heat island in hong kong department of architecture, chinese university of hong kong page 4 of 24 period. An urban heat island is a city or metropolitan area thats significantly warmer than its surrounding rural areas, due to human activities. The urban heat island may also increase cloudiness and precipitation in the city. Ppt urban heat island effect powerpoint presentation free. This compendium was developed by the climate protection partnership division in the u. The summer urban heat island uhi effect is a daytime elevation in the outdoor urban air temperature that results in part from the replacement of trees and other vegetation with buildings, roads and other heatabsorbing infrastructure causes. Final report on urban planning characteristics to mitigate climate change in context of urban heat island effect v list of tables table 31 characteristics of surface and atmospheric urban heat islands 3 14. The arrangement of a citys streets and buildings plays a crucial role in the local urban heat island effect, which causes cities to be hotter than their surroundings, researchers have found. The temperature increase is attributed to deforestation and the construction materials adopted for city building. Mar 31, 2010 the effects of vegetative cooling and the urban heat island effect research by.
Urban planning characteristics to mitigate climate change. Environmental protection agencys ofice of atmospheric programs. To find the appropriate predictors the relationship between different meteorological variables and the uhi of hamburg is analyzed. The effects of vegetative cooling and the urban heat island effect research by. Project design documents pdd are prepared in order to facilitate trading in carbon through. Atmospheric heat islands vary much less in intensity than surface heat islands. The summer urban heat island uhi effect is a daytime elevation in the outdoor urban air temperature that results in part from the replacement of trees and other vegetation with buildings, roads and other heat absorbing infrastructure. Jonathan winfrey, chris castro and zach bamman bsc 4932l.
Final report on urban planning characteristics to mitigate climate change in context of urban heat island effect v list of tables table 31 characteristics of. No, this is a separate phenomenon where cities are 68f warmer than surrounding rural areas. The urban heat island uhi effect in metropolitan sydney, summer 201516. A gis extension model to calculate urban heat island. Usually, under the urban heat island phenomenon, the central regions of urban centres. The upper boundary layer heat island is the link between uhi and global. The project is being done in conjunction with the urban forest action plan, which has an objective. Urban heat islands uhi are significantly warmer urban areas than its surrounding rural areas due to human activities. Tall buildings and narrow streets can heat air trapped between them and reduce air flow. For example, the average summer temperature in fresno is about 84 f, and the urban heat island effect averages 4 f, which is a relatively modest increase over a hot background. Virtually every city experiences an urban heat island effect, or the phenomenon in which cities are warmer than their rural surroundings. An urban heat island uhi is an urban area or metropolitan area that is significantly warmer.