• Title/Summary/Keyword: Urban heat-island phenomena

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Analysis of the Correlation between Urban High Temperature Phenomenon and Air Pollution during Summer in Daegu

  • An, Eun-Ji;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.28 no.10
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    • pp.831-840
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    • 2019
  • Recently, summer high temperature events caused by climate change and urban heat island phenomenon have become a serious social problem around the world. Urban areas have low albedo and huge heat storage, resulting in higher temperatures and longer lasting characteristics. To effectively consider the urban heat island measures, it is important to quantitatively grasp the impact of urban high temperatures on the society. Until now, the study of urban heat island phenomenon had been carried out focusing only on the effects of urban high temperature on human health (such as heat stroke and sleep disturbance). In this study, we focus on the effect of urban heat island phenomenon on air pollution. In particular, the relationship between high temperature phenomena in urban areas during summer and the concentration of photochemical oxidant is investigated. High concentrations of ozone during summer are confirmed to coincide with a day when the causative substances (NO2,VOCs) are high in urban areas during the early morning hours. Further, it is noted that the night urban heat island intensity is large.. Finally, although the concentration of other air pollutants has been decreasing in the long term, the concentration of photochemical oxidant gradually increases in Daegu.

A Study of Urban Heat Island in Chuncheon Using WRF Model and Field Measurements (관측과 기상모델을 이용한 춘천지역의 도시열섬현상 연구)

  • Lee, Chong-Bum;Kim, Jea-Chul;Jang, Yun-Jung
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.2
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    • pp.119-130
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    • 2012
  • Heat island phenomena in Chuncheon (Korea) were investigated using air temperature measured by automatic weather stations and temperature dataloggers located at rural and urban sites. Numerical simulation of the phenomena was performed using Weather Research and Forecasting Urban Canopy Model (WRF-UCM) and results were compared with the observation. The model was initialized with NCEP/FNL data. The horizontal resolution of the fine domain is 0.33 km. The results of observational analyses show that the intensity of heat island was significantly higher during the nighttime than during the daytime. The highest measured temperature difference between rural and urban site is $3.49^{\circ}C$ and average temperature difference varies between 1.4 and $1.9^{\circ}C$. Good agreement was found between the simulated and observed temperatures. However, significantly overestimated wind speed was found at the urban sites. The linear regression analysis between observed and simulated temperature shows high correlation coefficient 0.96 for urban and 0.94 for rural sites while for wind speed, a very low correlation coefficient was found, 0.30 and 0.55 respectively.

The Research of Planning Method of Adaption for Old Residential Neighborhoods According to Heat wave and Urban Heat-island Phenomena - Focused on Gun-Ja Dong, Gwang-Jin Gu - (폭염 및 도시열섬현상에 따른 노후 주거지의 적응 계획기법에 관한 연구 - 광진구 군자동 중심으로 -)

  • Kim, Min-Young;Moon, Eun-Seol
    • KIEAE Journal
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    • v.16 no.4
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    • pp.31-39
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    • 2016
  • Purpose: Urban heat island and Heat wave raise urban temperature and create damage of human life. Growing up as quantitative supply to solve shortage of housing, Urban residential area in Korea have a low rate of nature surface and heavily population makes temperature rise. Most houses in the declined residential area are multi-family rental housing and have many factors congesting housing environment such as narrow in-between space, outdoor staircases, walls and semi-basement floor, which make thermal environment getting worse. Most of the residents in this area are small tenants vulnerable to climate change adaptation, This damage is expected to be even greater. This study focus on multiple dwelling in urban residential area prone to temperature rise and draw temperature adaption method that can apply to multiple dwelling.

The Impact of Urban Heat Island-induced Temperature Differences on the Hatching Rates of Aedes albopictus (도시열섬 현상에 의한 기온차이가 흰줄숲모기(Aedes albopictus) 부화율에 미치는 영향)

  • Jihun Ryu;Kwang Shik Choi
    • Korean journal of applied entomology
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    • v.63 no.1
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    • pp.77-80
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    • 2024
  • Aedes albopictus, a common species in the Republic of Korea, is internationally known as a major vector for various diseases, and it is well-adapted to urban environments. Recent insect outbreaks in urban areas, attributed to climate change and urban heat islands, have increased the necessity of researching the effects on mosquito populations. This study analyzed climate data from 25 Automatic Weather System (AWS) stations in Seoul, identifying urban areas with pronounced heat island effects and suburban areas with milder effects. Nine urban heat island conditions were established based on this analysis, under which the hatching rates of Ae. albopictus were examined. The results revealed an increase in hatching rates correlating with the intensity of the urban heat island effect. Regression analysis further indicated that this trend accelerates as the strength of the heat island effect increases. This study suggests that temperature variations resulting from urban heat island phenomena can significantly influence the hatching rates of Ae. albopictus.

Aspects of Urban Heat Island and Its's Effect on Air Pollution Concentration in Chunchon Area (춘천지역 도시열섬의 특성과 대기질에 미치는 영향)

  • 이종범;김용국;김태우
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.303-309
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    • 1993
  • An observational study of urban heat island was carried out using field data obatined during 6 days in May and August 1992 in Chunchon(population size 180.000). Air temperature was measured at 64 points along two sampling ruoutes by themisters attached to cars. Both routes cover urban and rural area and across the cneter of urban area. Continuous observation of air sonde was perfomed to clarify heights of nocturnal boundary layer(NBL) at the center of urban area. Surface meteorological observations were performed at both urban and rural sites. This study showed that heat island phenomena was obviously observed at the urbanized area during the night time with low wind speed. The average NBL heights exteded to about 10 meters, but varied with meteorological conditions. After sunset, the air temperature decreased with time at both sites and cooling rate at the urban site was greater than the rural site. The maximum heat island intensity was 7.5$^{\circ}$C at 21 LST, May 4. Usingthe two meteorological data sets obtained from urban and rural sites, the air pollutant concentration was calculated by Gaussian plume model which can obtain not only horizontal distribution of concentration but also vertical distribution. The result indicated that the concentration resulted from urban meteorological data set was lower than that from rural meteorological data set. It was also calculated that the air pollutant extended to higher level in urban meteorological data set than that in rural meteorological data set.

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Heatwave Vulnerability Analysis of Construction Sites Using Satellite Imagery Data and Deep Learning (인공위성영상과 딥러닝을 이용한 건설공사현장 폭염취약지역 분석)

  • Kim, Seulgi;Park, Seunghee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.263-272
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    • 2022
  • As a result of climate change, the heatwave and urban heat island phenomena have become more common, and the frequency of heatwaves is expected to increase by two to six times by the year 2050. In particular, the heat sensation index felt by workers at construction sites during a heatwave is very high, and the sensation index becomes even higher if the urban heat island phenomenon is considered. The construction site environment and the situations of construction workers vulnerable to heat are not improving, and it is now imperative to respond effectively to reduce such damage. In this study, satellite imagery, land surface temperatures (LST), and long short-term memory (LSTM) were applied to analyze areas above 33 ℃, with the most vulnerable areas with increased synergistic damage from heat waves and the urban heat island phenomena then predicted. It is expected that the prediction results will ensure the safety of construction workers and will serve as the basis for a construction site early-warning system.

Analysis of the Surface Urban Heat Island Changes according to NewTowns Development and Correlation with Urban Morphology (신도시 개발에 따른 표면 열섬현상 변화분석 및 도시 형태와의 상관관계)

  • Kyungil Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.921-932
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    • 2023
  • Land cover change due to urban population concentration and urban expansion can cause various environmental problems such as urban heat islands. In particular, New towns are considered an appropriate study site to analyze changes in urban climate due to rapid urbanization in a short period. This study used Landsat satellite imagery to compare and analyze the land cover changes before and after the development of two new towns with different plans, and the resulting changes in surface urban heat island (SUHI) phenomena. Correlation analysis was also conducted between urban structural features that may affect the SUHI intensity. The results of the analysis confirm the rapid change in land cover as new town development progresses and the direct intensification of the SUHI phenomenon. This study confirms the differences in SUHI caused by different urban plans and suggests the need for three-dimensional urban planning to improve the thermal environment.

Numerical Simulation for Urban Climate Assessment and Hazard (도시기후 평가와 방재를 위한 도시기상 수치모의)

  • O, Seong-Nam
    • Magazine of the Korean Society of Hazard Mitigation
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    • v.2 no.4 s.7
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    • pp.40-47
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    • 2002
  • Since it is important to understand the bio-climatic change in Seoul for ecological city planning in the future, this paper gives an overview on bio-climate analysis of urban environments at Seoul. We analyzed its characteristics in recent years using the observations of 24 of Automatic Weather Station (AWS) by Korea Meteorological Administration (KMA). In urbanization, Seoul metropolitan area is densely populated and is concentrated with high buildings. This urban activity changes land covering, which modifies the local circulation of radiation, heat and moisture, precipitation and creating a specific climate. Urban climate is evidently manifested in the phenomena of the increase of the air temperature, called urban heat Island and in addition urban sqall line of heavy rain. Since a city has its different land cover and street structure, these form their own climate character such as climate comfort zone. The thermal fold in urban area such as the heat island is produced by the change of land use and the air pollution that provide the bio-climate change of urban eco-system. The urban wind flow is the most important climate element on dispersion of air pollution, thermal effects and heavy shower. Numerical modeling indicates that the bio-climatic transition of wind wake in urban area and the dispersion of the air pollution by the simulations of the wind variation depend on the urban land cover change. The winds are separately simulated on small and micro-scale at Seoul with two kinds of kinetic model, Witrak and MUKLIMO.

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EVALUATION OF SURFACE HEAT FLUXES FOR DIFFERENT LAND COVER IN HEAT ISLAND EFFECT

  • Chang, Tzu-Yin;Liao, Lu-Wei;Liou, Yuei-An
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.68-71
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    • 2008
  • Our goal is to obtain a better scientific understanding how to define the nature and role of remotely sensed land surface parameters and energy fluxes in the heat island phenomena, and local and regional weather and climate. By using the MODIS visible and thermal imagery data and analyzing the surface energy flux images associated with the change of the landcover and landuse in study area, we will estimate and present how significant is the magnitude of the heat island heat effect and its relation with the surface parameters and the energy fluxes in Taiwan. To achieve our objective, we used the energy budget components such as net radiation, soil heat flux, sensible heat flux, and latent heat flux in the study area of interest derived form remotely sensed data to understand the island heat effect. The result shows that the water is the most important component to decrease the temperature, and the more the consumed net radiation to latent heat, the lower urban surface temperature.

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Comparing a Perspective on the Leaf Burst Timing and Leaf Growth Performance of Major Plants observed in Urban Forests (도시녹지 내 주요 식물상의 개엽시기 및 잎의 성장 특성 비교)

  • Jang, Gab-Sue
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.2
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    • pp.127-136
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    • 2012
  • Global climate change and urban heat island have been the main factors which changed leaf burst timing and leaf growth performance in urban forests. Therefore, the ecosystem in urban forests were modified and the types and composition of wildlives, living in the urban forests, were desperately changed due to the urban heat island. This study was done to identify phenological phenomena appeared in urban forests due to the urban climate change by comparing the morphological changes of leaves due to the change of temperature in Spring. The study focused on nine urban forests distributed in Daegu city, where weekly temperature and the morphological changes of the plants were mainly observed. Urban forests had different temperature depending on where each was located in the urban area. The difference of temperature in forests in and outside the urban area was verified by SPSS (Statistical Package for the Social Sciences), which divided the urban forests into about three groups; the one located outside the city, another group located in the middle of the city, and the other located close to the outside forests. The forests located in the middle of the city were showing the earlier leaf burst timing and leaf growth performance, while forests, distributed outside the city, were showing relatively late leaf burst timing and leaf performance.