• Title, Summary, Keyword: Heat island

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A Study on the Mitigation Policies for Urban Heat Island (도시열섬 완화를 위한 제도개선)

  • Suh, Eung Chul
    • KIEAE Journal
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    • v.7 no.2
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    • pp.17-23
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    • 2007
  • While heat island has been recognized as an unique environmental nuisance in cities, the phenomenon tends to be regarded as an inevitable side effect on urbanization. Recently the nature of the heat island has been disclosed and efforts for the remedy have been discussed in many ways. Some pioneering actions have been taken to mitigate the strength of the heat island's intensity in several countries. After studies for the heat island and speculations on current pilot policies of 3 different countries has been done, mitigation policies for heat island has been suggested as followings. 1. Preservation of natural topography is essential because latent energy consumption(evapotranspiration) from the site is the single most important factor to mitigate the energy surplus caused by urban heat island. 2. Because current national zoning ordinance or building law can not effectively control the site specific local environment, heat island policy should be established or employed at local level. 3. Incentives for the mitigation should be adopted on the process of implementation because environment is public concern. 4. Wind can easily dissipate energy surplus which is the major driving force for heat island. Therefore local wind, the direction and intensity should be sustained and sometimes facilitated fully through policies.

Heat Island Intensity in Seongseo, Daegu, South Korea - a Rural Suburb Containing Large Areas of Water

  • Kim, Ki-Young;Byon, Jae-Young;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.22 no.10
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    • pp.1337-1344
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    • 2013
  • We examined urban heat island intensity in Seongseo, Dae gu, South Korea, where a large area of water is located within the suburb. We found a maximum urban heat island intensity of $4.2^{\circ}C$, which occurred around 7 PM in the summer season. Throughout the remainder of the year, we observed the largest heat island intensity levels during late night hours. In contrast, the winter season displayed the smallest values for heat island intensity. Our results conflicted with heat island intensity values for cities where suburbs did not contain water areas. Generally, cities with suburbs lacking water displayed the largest heat island intensity levels before sunrise in the winter season. We also observed negative urban heat island intensity levels at midday in all seasons except for the summer, which is also in contrast with studies examining suburbs lacking water areas. The heat island intensity value observed in this study ($4.2^{\circ}C$) was relatively large and fell between the averages for, Asia and Europe according to the relationship between urban population and heat island intensity.

An empirical study on the Definition and Classification Methodology of Urban Heat Island Areas (도시열섬 지역에 대한 정의 및 구분 방법론에 관한 비교연구)

  • Kim, Kijung;An, Youngsoo
    • Journal of the Korean Regional Science Association
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    • v.33 no.2
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    • pp.47-59
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    • 2017
  • The purpose of this study is to examine various definitions of urban heat island and to analyze the characteristics and differences of each methodology by applying each methodology for deriving the heat island region to Seoul. The definition of the heat island is divided into the atmospheric heat island and the surface heat island according to the utilized temperature data. The methodology for deriving the heat island area differs depending on the comparison method and the spatial extent of the analysis. As a result of analyzing each methodology for Seoul city, it was confirmed that the heat island area of Seoul is different according to temperature data. Also, it is confirmed that the distribution range of the heat island area is different according to the spatial range of analysis. This shows that even if the heat island area is analyzed for the same space and the same view point, the heat island area is derived differently according to each methodology. This study can be used as a basic study to solve the urban heat island problem in the future.

Thermal Infrared Remote Sensing Data Utilization for Urban Heat Island and Urban Planning Studies

  • Lee, Hye Kyung
    • Journal of KIBIM
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    • v.7 no.2
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    • pp.36-43
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    • 2017
  • Population growth and rapid urbanization has been converting large amounts of rural vegetation into urbanized areas. This human induced change has increased temperature in urban areas in comparison to adjacent rural regions. Various studies regarding to urban heat island have been conducted in different disciplines in order to analyze the environmental issue. Especially, different types of thermal infrared remote sensing data are applied to urban heat island research. This article reviews research focusing on thermal infrared remote sensing for urban heat island and urban planning studies. Seven studies of analyses for the relationships between urban heat island and other dependent indicators in urban planning discipline are reviewed. Despite of different types of thermal infrared remote sensing data, units of analysis, land use and land cover, and other dependent variable, each study results in meaningful outputs which can be implemented in urban planning strategies. As the application of thermal infrared remote sensing data is critical to measure urban heat island, it is important to understand its advantages and disadvantages for better analyses of urban heat island based on this review. Despite of its limitations - spatial resolution, overpass time, and revisiting cycle, it is meaningful to conduct future research on urban heat island with thermal infrared remote sensing data as well as its application to urban planning disciplines. Based on the results from this review, future research with remotely sensed data of urban heat island and urban planning could be modified and better results and mitigation strategies could be developed.

Effect of the Geothermal Heat-pump on alleviation of the Urban Heat Island (지열히트펌프의 도심 열섬 저감 효과의 검토)

  • Son, Won-Tug
    • Journal of the Korean Solar Energy Society
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    • v.36 no.3
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    • pp.45-52
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    • 2016
  • Remarkable air temperature increases in urban areas are known as heat island phenomenon. In this study, we analyzed the effects of renewable energy on the heat island phenomenon in urban area by numerical method. The results showed that the use of renewable energy reduces the building energy use in urban area and contributes the alleviation of the Urban Heat Island Effects.

On the Seasonal Variation of Urban Heat Island Intensity According to Meteorological Condition in Daegu (대구지역의 기상조건에 따른 도시열섬강도의 계절별 변화특성)

  • Ahn Ji-Suk;Kim Hae-Dong
    • Journal of Environmental Science International
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    • v.15 no.6
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    • pp.527-532
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    • 2006
  • The purpose of this study is to clarify the characteristic of urban heat island intensity in urban area formed at a basin. Thermal environments for basin-type cities are influenced by significant topographic relief winds. In this study, we analyzed the diurnal variations of the heat island intensity according to meteorological condition and season using AWS(Automatic Weather observation System) data in Daegu Metropolitan area for 1 year(3/April, 2003 $\sim$ 2/April, 2004). In this study, we defined the urban heat island intensity as the air temperature difference between two points, the downtown and the suburban area. The suburban area is located at valley mouth around the western tip of Daegu. The results are summarized as follows; 1. The maximum heat island intensity was recorded at early morning under the meteorological conditions, calm and clear 2. The heat island intensity was strong in the order of winter, fall, spring and summer. 3. The heat island intensity came out minus values in the afternoon. This phenomenon is known as a com mon for basin-type cities. 4. The heat island intensity was twice or more in clear and calm than not so.

Impact of Vegetation in Reducing Heat Island Phenomenon of Fukuoka City By Applying Remote Sensing Technique

  • Shibata Satoshi;Gotoh Keinosuke;Tachiiri Kaoru
    • Proceedings of the KSRS Conference
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    • pp.541-544
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    • 2004
  • Recently, the heat island phenomenon in which the temperature of a city part rises from the circumference ground has developed into a big problem. In this study, we aimed at examining the impact of increasing vegetation in urban areas to reduce the heat island phenomenon by taking the Fukuoka City of Japan as a case. In order to discuss the relation between vegetation environment and the heat island phenomenon, we have calculated Normalized Difference Vegetation Index (NDVI) and mapped the spatial vegetation distribution. These are then compared with the heat island phenomenon investigations in Fukuoka City. The results of the study revealed that the areas showing comparatively lesser heat island phenomenon are those having increased vegetation.

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An Analysis on the Variation Trend of Urban Heat Island in Busan Area (2006-2010) (부산지역 도시 열섬의 변화경향 분석 (2006-2010))

  • Do, Woo-Gon;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.21 no.8
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    • pp.953-963
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    • 2012
  • The annual variations of the urban heat island in Busan is investigated using surface temperature data measured at 3 automatic weather stations(AWSs) for the 5 years period, 2006 to 2010. Similar to previous studies, the intensity of the urban heat island is calculated using the temperature difference between downtown(Busanjin, Dongnae) and suburb(Gijang). The maximum hourly mean urban heat island are $1.4^{\circ}C$ at Busanjin site, 2300LST and $1.6^{\circ}C$ at Dongnae site, 2100LST. It occurs more often at Dongnae than Busanjin. Also the maximum hourly mean urban heat island appears in November at both sites. The urban heat island in Busan is stronger in the nighttime than in the daytime and decreases with increasing wind speed, but it is least developed in summer. Also it partly causes the increasement of nighttime PM10 concentration.

A Satellite View of Urban Heat Island: Causative Factors and Scenario Analysis

  • Wong, Man Sing;Nichol, Janet;Lee, Kwon-Ho
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.617-627
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    • 2010
  • Although many researches for heat island study have been developed, there is little attempt to link the findings to actual and hypothetical scenarios of urban developments which would help to mitigate the Urban Heat Island (UHI) in cities. The aim of this paper is to analyze the UHI at urban area with different geometries, land use, and environmental factors, and emphasis on the influence of different geometric and environmental parameters on ambient air temperature. In order to evaluate these effects, the parameters of (i) Air pollution (i.e. Aerosol Optical Thickness (AOT)), (ii) Green space Normalized Difference Vegetation Index (NDVI), (iii) Anthropogenic heat (AH) (iv) Building density (BD), (v) Building height (BH), and (vi) Air temperature (Ta) were mapped. The optimum operational scales between Heat Island Intensity (HII) and above parameters were evaluated by testing the strength of the correlations for every resolution. The best compromised scale for all parameters is 275m resolution. Thus, the measurements of these parameters contributing to heat island formation over the study areas of Hong Kong were established from mathematical relationships between them and in combination at 275m resolution. The mathematical models were then tabulated to show the impact of different percentages of parameters on HII. These tables are useful to predict the probable climatic implications of future planning decisions.

Analysis of the Effects of Advection and Urban Fraction on Urban Heat Island Intensity using Unified Model for Seoul Metropolitan Area, Korea (통합모델을 활용한 이류와 도시비율이 서울 수도권 지역의 도시열섬강도에 미치는 영향 분석)

  • Hong, Seon-Ok;Kim, Do-Hyoung;Byon, Jae-Young;Park, HyangSuk;Ha, Jong-Chul
    • Atmosphere
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    • v.29 no.4
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    • pp.381-390
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    • 2019
  • This study investigates the impacts of urban land-use fraction and temperature advection on the urban heat island intensity over the Seoul metropolitan area using the UM (Unified Model) with the MORUSES (Met Office Reading Urban Surface Exchange Scheme) during the heat wave over the region from 2 to 8, August 2016. Two simulations are performed with two different land-use type, the urban (urban simulation) and the urban surfaces replaced with grass (rural simulation), in order to calculate the urban heat island intensity defined as the 1.5-m temperature difference between the urban and the rural simulations. The land-use type for the urban simulation is obtained from Korea Ministry of Environment (2007) land-use data after it is converted into the types used in the UM. It is found that the urban heat island intensity over high urban-fraction regions in the metropolitan area is as large as 1℃ in daytime and 3.2℃ in nighttime, i.e., the effects of urban heat island is much larger for night than day. It is also found that the magnitude of urban heat island intensity increases linearly with urban land-use fraction. Spatially, the estimated the urban heat island intensities are systematically larger in the downwind regions of the metropolitan area than in the upwind area due to the effects of temperature advection. Results of this study indicate that urban surface fraction in the city area and temperature advection play a key role in determining the spatial distribution and magnitude of urban heat island intensity.