• Title/Summary/Keyword: urban temperature

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Impacts of anthropogenic heating on urban boundary layer in the Gyeong-In region (인공열이 도시경계층에 미치는 영향 - 경인지역을 중심으로 -)

  • Koo, Hae-Jung;Ryu, Young-Hee
    • Journal of Environmental Impact Assessment
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    • v.21 no.5
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    • pp.665-681
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    • 2012
  • This study investigates the influence of anthropogenic heat (AH) release on urban boundary layer in the Gyeong-In region using the Weather Research and Forecasting model that includes the Seoul National University Urban Canopy Model (SNUUCM). The gridded AH emission data, which is estimated in the Gyeong-In region in 2002 based on the energy consumption statistics data, are implemented into the SNUUCM. The simulated air temperature and wind speed show good agreement with the observed ones particularly in terms of phase for 11 urban sites, but they are overestimated in the nighttime. It is found that the influence of AH release on air temperature is larger in the nighttime than in the daytime even though the AH intensity is larger in the daytime. As compared with the results with AH release and without AH release, the contribution of AH release on urban heat island intensity is large in the nighttime and in the morning. As the AH intensity increases, the water vapor mixing ratio decreases in the daytime but increases in the nighttime. The atmospheric boundary layer height increases greatly in the morning (0800 - 1100 LST) and midnight (0000 LST). These results indicate that AH release can have an impact on weather and air quality in urban areas.

Granger Causality between Thermal Environment and PM10 of Seoul's 25 Districts (서울특별시 25개 자치구의 열환경과 미세먼지 간 Granger 인과관계)

  • Youn, Jee Min;Kim, Hyungkyoo
    • Journal of Environmental Science International
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    • v.31 no.1
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    • pp.9-21
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    • 2022
  • Today's cities require deeper understanding of the thermal environment and PM10 as their management becomes more critical. Based on these circumstances, this study investigated the Granger causality between the thermal environment and PM10 of the 25 districts of Seoul, the most populous and urbanized city in Korea. The results of the Granger causality test on the thermal environment and PM10 were classified into 12 types. Except for type 12, the temperature and urban island heat intensity of the other 11 types operated as a Granger-cause to each other in both directions. Temperature operates as a Granger-cause of urban island heat intensity in type 12. The PM10 level and urban pollution island intensity operated as a Granger-cause to each other in all districts. For types 1 and 2, thermal environment operated as a Granger-cause to PM10 in one direction, and type 3-type 12 confirmed that thermal environment and PM10 operated as a Granger-cause in both directions. Findings reveal the intricate causalities between thermal environment and PM10 at the district level and suggest mitigation strategies that are more location based.

Factor Analysis of the Relation Between Land Cover Ratio of Green Spaces and Temperature (공원녹지의 토지피복비율과 기온간의 요인분석)

  • Yoon, Yong-Han;Park, Bong-Ju;Kim, Won-Tae;Park, Sun-Young
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.485-491
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    • 2008
  • The present study examined the relation between land cover condition and temperature in various types of urban green spaces. The diagram of temperature distribution showed that high-temperature zones are formed around paved areas, and low temperature zone around planted areas and grassy areas. Even in planted areas where low-temperature zones were formed, temperature was different according to hierarchical structure. That is, temperature was relatively low in areas covered with arbor + sub-arbor. With regard to land cover ratio, the increase of planted areas and grassy areas had an effect on the fall of temperature and the effect was higher in order of planted areas and grassy areas. On the contrary, paved areas and bare areas had an effect on the rise of temperature. According to the results of factor analysis, in case of the highest temperature, planted area and grassy area were put together into a factor lowering temperature, paved area and temperature into a factor raising temperature, and bare area alone into a factor of low significance. In case of the lowest temperature, grassy area and bare area were put together into a factor, and the validity of the factor analysis was proved by the analysis of urban heat islands. An increase in the number of trees by height was effective in lowering temperature, and the effect was high in order to arbor and sub-arbor, and the source of coldness in planted area was tall trees.

Study on the Urban Heat Island(UHI) using Remote Sensing data

  • Kyung, H.M.;Kim, Y.S.;Park, K.W.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.846-848
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    • 2003
  • Analysis of UHI in Busan region using Landsat TM data. Between 1987 and 1997 surface temperature increased clearly. Land usage of Busan is construed that instigate UHI changing into industry and commerce area. Also, intensity of UHI in surface temperature appeared strongly in industrial area and business area. On the contrary, residential area, mountain area, suburb area did not appear strongly.

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A Study on the Factors Affecting Air Temperature on Roadside : Focusing on Road Conditions and Traffic Characteristics (도로 주변부 기온에 영향을 미치는 요인에 관한 연구: 도로조건과 교통특성을 중심으로)

  • Lee, Yuhwa;Yang, Inchul;Kim, Do-Gyeong;Lim, Ji Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1619-1629
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    • 2013
  • It turned out that there was a direct or an indirect relationship among global warming, urban heat island effects, urban and traffic environments, and public's health. In particular, unusual climate phenomena such as frequent heavy rainfall and scorching heat in a row that had rarely happened before have a negative effect on quality of life for people living in urban areas. This study focuses on the effects of roadway geometric design and traffic conditions on air temperature of roadside in Seoul Metropolitan Areas, controlling of roadway micro-climate environment. Five roadway segments containing different roadway and traffic conditions in terms of traffic median with trees, street trees, traffic volume and average travel speeds were surveyed. According to statistical results(t-test) from three roadway air temperature regression model estimations, air temperature is found to be different from one another in three periods-morning, afternoon and evening. Regarding roadway geometric design, air temperature of urban roads with vegetated median strips is lower about 1.3~2.2 degrees in celcius. Higher traffic volumes per lane and lower average travel speeds will tend to increase roadside air temperature, and efficient traffic operation policies can protect from increasing roadside air temperature in urban areas.

The Relationship among Land Use, Vegetation and Surface Temperature in Urban Areas -The Case of Deagu City- (도시지역 지표온도와 토지이용 및 식생상태와의 상관관계에 관한 연구 : 대구광역시의 경우)

  • Kim, Jae Ik;Yeo, Chang-Hwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.2
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    • pp.21-30
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    • 2005
  • The primary purpose of this paper is to prove a clear relationship among land use type, vegetation level and surface temperature. For this purpose, this paper presents series of spatial distribution maps of the three features obtained through the visual interpretation of digital images. The result of study tells us that the spatial distribution of the vegetation level is very similar with that of surface temperature. By analyzing the relationship between surface temperature and land use types, this study categorizes the eighteen urban land uses into 7-8 groups according to their average surface temperature. The Duncan test was conducted to categorize the land uses. The surface temperature of manufacturing related land use is the highest, semi-residential use is the next, non-residential land use is the next to the lowest, and the agricultural and forest land use is the lowest. This paper provides another strong evidence of the relationship by showing the regression result.

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Effects of Land Use Pattern on Urban Heat Island in Chungju City (토지이용형태가 도시열섬현상에 미치는 영향 - 충주시를 사례로 -)

  • Yoon, Yong-Han;Bae, Byung-Ho;Kim, Won-Tae;Park, Bong-Ju;Cho, Sung-Moh;Cho, Hyun-Soo
    • Journal of Environmental Science International
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    • v.16 no.9
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    • pp.1063-1069
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    • 2007
  • The present study investigated the causes and intensity of the urban heat island phenomenon by the seasons according to the pattern of land use in Chungju City. Highest temperature and lowest moisture areas of the urban were very similar to the distribution of commercial districts, on the other hand, lowest temperature and highest moisture areas were distributed in manufacturing districts, green zones and the Hoam Lake. If appear at intensity of the distance from the outer circumference of commercial districts, wind direction and the rise of temperature, we could observe the remarkable expansion of high temperature from commercial districts toward residential districts around of downwind in all seasons. In case the effect of the wind was not significant as well, high temperature in commercial districts appeared tendency that a little spread to 1, 2 residential districts around. But checked up the intimate relations between the amount of moving heat and wind, when out of consideration that size of area was not much compared than residential areas of downwind affected by the wind. These phenomenon was relatively obvious in summer, the other side, in spring and autumn appeared a similar tendency.

Analysis of Temperature Change by Forest Growth for Mitigation of the Urban Heat Island (도시열섬 완화를 위한 녹지증가에 따른 온도변화 분석)

  • Yun, Hee Cheon;Kim, Min Gyu;Jung, Kap Yong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.2
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    • pp.143-150
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    • 2013
  • Recently, environmental issues such as climate warming, ozone layer depletion, reduction of tropical forests and desertification are emerging as global environmental problems beyond national problems. And international attention and effort have been carried out in many ways to solve these problems. In this study, the growth of green was calculated quantitatively using the technique of remote sensing and temperature change was figured out through temperature extraction in the city. The land-cover changes and thermal changes for research areas were analyzed using Landsat TM images on May 2002 and May 2009. Surface temperature distribution was calculated using spectral degree of brightness of Band 6 that was Landsat TM thermal infrared sensor to extract the ground surface temperature in the city. As a result of research, the area of urban green belt was increased by 2.87km2 and the ground surface temperature decreased by 0.6C0.8C before and after tree planting projects. Henceforth, if the additional study about temperature of downtown is performed based on remote sensing and measurement data, it will contribute to solve the problems about the urban environment.

Comparison of the Thermal Environment in the Downtown Location and the Outskirt Site base on the Field Observations in the Summer (미기상 관측을 통한 하절기 도심과 외곽의 열환경 비교)

  • Jung, Im-Soo;Choi, Dong-Ho;Lee, Bu-Yong
    • Journal of the Korean Solar Energy Society
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    • v.29 no.6
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    • pp.94-101
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    • 2009
  • This study which is the fundamental work to investigate the property of urban climate compared the property of thermal environment in the downtown location and the outskirt site based on the field observation in the summer. We analysed thermal environment in the downtown location mainly by distributional characteristics during day and night with changes and correlation analysis of the air temperature, the globe temperature and the surface temperature through the simultaneous observation of the property of thermal environment at two places in real time. The summary of finding in this study is as follows. (1)It is observed on the day chosen by sample that diurnal air temperature range in the downtown location is 22.334.9C, and diurnal air temperature range in the Outskirt site is 20.034.3C, so, we found that the diurnal air temperature range in the outskirt site is 1.7C higher than in the downtown location. (2)In comparison of the globe temperature after sunset, we found the change of more sudden temperature drops in the outskirt site than in the downtown location. (3)It is observed on the days chosen by sample that the average of globe temperature range is 1.1C, the average of surface temperature range is 1.0C, and air temperature range is 2.0C, thus, the we found that the average of air temperature is 1.0C higher than globe temperature and the surface temperature. (4)After the consideration of air temperature and globe temperature distribution, the highest temperature reaching time of globe temperature is one hour earlier than air temperature in the downtown location, on the other hand, although the highest temperature reaching time of globe temperature in the outskirt sites is one hour later than in the downtown location, the timelag found in the downtown location was not found in the outskirt site.

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.