• Title/Summary/Keyword: Heat island phenomenon

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Study on Improvement of Thermal Environment by Green Roof Systems on RC Building - utilization of solar insulating block and the grass - (옥상녹화에 따른 콘크리트 건축물의 열환경 개선효과 -일사차폐블록과 잔디를 대상으로-)

  • Park, Chanpil;Furukawa, Nobuhisa
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.1
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    • pp.1-9
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    • 2004
  • Caused on the excessive heat accumulation of concrete material, the indoor thermal environment of reinforced concrete building is so bad in Okinawa. As the interruption of solar radiation could be one of the methods to improve it, the purpose of this study is to find out the effect of adopting solar radiation interrupting materials -Solar insulating block, Grass, and both of them- for the improvement of thermal environment. As the result, it was found that grass on the solar insulating block which has an air layer obviously improved the indoor thermal environment of RC building which was applied to. And it was found that the systems have an effectuality on heat island phenomenon simultaneously. It could be proposed as a good system which improve the indoor thermal environment of the existent houses.

Analysis of Relationship between Vegetation Cover Rates and Surface Temperature Using Landsat TM Data (Landsat TM 데이터에 의한 식생피복율과 지표면온도와의 관계 해석)

  • Park, Jong-Hwa;Na, Sang-Il;Kim, Jin-Su
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.569-573
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    • 2005
  • Land surface temperature(LST) is one of the key parameters in physics and meteorology of land-surface processes on regional and global scales. Urban Heat Island(UHI), a meteorological phenomenon by which the air temperature in an urban area increases beyond that in the suburbs, grows with the progress of urbanization. Satellite remote sensing has been expected to be effective for obtaining thermal information of the earth's surface with a high resolution. The main purpose of this study is to produce LST map of Cheongju and to analyze the spatial distributions of surface heat fluxes in urban areas. This study, taking Cheongju as the study area, aims to examine relationship between vegetation cover rates and surface temperature, and to clarify a method for calculation surface temperature with Landsat TM thermal images.

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Change of Thermal Environment with Urban Expansion (도시 확장에 따른 온열환경의 변화)

  • Kim, Sang-Jin
    • Journal of the Korean Solar Energy Society
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    • v.27 no.2
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    • pp.95-101
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    • 2007
  • The surface changes due to urban expansion and the increase of artificial heat releases have brought significant climate changes such as heat island phenomenon in urban area. Furthermore, these changes also have brought serious problems such as air temperature increase, wind changes, and air pollution in urban area. Comprehensive analytical technologies considering various effects are required to analyse complicated mechanism of climate changes, and review the efficient measures. In this research, the effect of the urban expansion in Tokyo and Bangkok area on urban environment will be discussed. By using CFD, urban development and the mechanism of global warming and wind change are studied in those two cities. As a result of numerical research, the surface changes of city could bring the environmental changes in urban area.

A Study on the Temperature Controlled Performance of Thermal Reflective Exterior Finishes (열반사성 외장마감재의 온도조절 성능에 관한 연구)

  • Ryu, Hwa-Sung;Shin, Sang-Heon;Song, Sung-Yong;Kim, Deuck-Mo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.186-187
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    • 2019
  • In modern times, due to the centralized urban structure, the interval between buildings is narrow and the increase of the heat island phenomenon due to the accumulation of the structure is becoming a social problem. In order to solve these problems, various materials for reducing the surface temperature of buildings are under study. Particularly, in the case of a wall part which is a part directly affected by the outside air of the building, it is a main structural part for determining the room temperature. The purpose of this study was to develop a material that can improve the thermal environment performance of the building by evaluating the temperature control performance of the exterior finishing material using the heat reflecting material as a method for controlling the temperature of the outer wall finishing material.

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Estimation of Urban Heat Island Potential Based on Land Cover Type in Busan Using Landsat-7 ETM+ and AWS Data (Landsat-7 ETM+ 영상과 AWS 자료를 이용한 부산의 토지피복에 따른 여름철 도시열섬포텐셜 산출)

  • Ahn, Ji-Suk;Hwang, Jae-Dong;Park, Myung-Hee;Suh, Young-Sang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.65-77
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    • 2012
  • This study examined changes in land cover for the past 25 years in Busan and subsequently evaluated heat island potential by using land surface temperature and observation temperature data. The results were as below. The urban area of Busan increased by more than 2.5 times for the past 25 years from 1975 to 2000. It was believed that an increase in the pavement area of city within such a short period of time was an unprecedented phenomenon unique to our country. It could be assumed that urban heat island would be worsened through this process. After analyzing the land temperature according to the land cover, it was shown that there were noticeable changes in the temperature of urban & built-up and mountain & forest areas. In particular, the temperature rose to $36{\sim}39^{\circ}C$ in industrial areas during the summer, whereas it went down to $22{\sim}24^{\circ}C$ in the urban areas at whose center there were mountains. It was found that heat island potential according to the level of land cover had various values depending on the conditions of land cover. Among the areas of urbanization, the industrial area's heat island potential is 6 to $8^{\circ}C$, and the residential and commercial area's is $0{\sim}5^{\circ}C$, so it has been found that there is high possibility to induce urban heat islands. Meanwhile, in the forest or agricultural area or the waterside, the heat island potential is $-6{\sim}-3^{\circ}C$. With this study result, it is possible to evaluate the effects of temperature increase according to the urban land use, and it can be used as foundational data to improve urban thermal environment and plan eco-friendly urban development.

A Survey on the Electric Power Consumptions of Apartments located at Coastal Area : Yeongdo-gu, Busan, Korea (연안지역 아파트의 전력소비량 실태조사 - 부산광역시 영도구에 대한 사례연구 -)

  • Hwang, Kwang-Il
    • Journal of Navigation and Port Research
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    • v.33 no.3
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    • pp.241-245
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    • 2009
  • Because of the heat island phenomenon and sea wind, there can be thermal conditions' differences around buildings at downtown and coastal area respectively in coastal city, like Busan, Incheon, Mokpo. For the final purpose of the buildings' energy saving design and operation considering of above mentioned environments differences, energy consumption including heating and cooling loads, electric loads are necessary to be accumulated and analyzed in as the database. As a part of this concept, this study aims to survey and analyze each loads of 22 apartments which has at least 100 households respectively and is located at Yeongdo island, Busan, Korea It is cleared that despite the residents living in this district can use sea wind as a natural ventilation and/or cooling methods, they mainly depends on the electric-driven air-conditioners for cooling with window-closed because of anti-salt problems of the sea wind. This leads the maximum power consumption of the surveyed-22-apartments to be appeared in August like that of inland buildings.

An Experimental Study of Surface Materials for Planting of Building Surface by the Radiant Heat Balance Analysis in the Summer (하절기 실험을 통한 건물녹화용 피복재료의 복사수지 해석)

  • Choi, Dong-Ho;Lee, Bu-Yong
    • Journal of the Korean Solar Energy Society
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    • v.30 no.3
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    • pp.71-80
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    • 2010
  • This study carried out to understand the thermal characteristics of various surface material which compose the city through the observation in the summer. To examine passive cooling effect of planting of building, it is arranged four different materials that is natural grass, grass block, concrete slab and artificial grass. The results of this study are as follows; (1) Natural grass and grass block show the lower surface temperature because of the structures of leaf can do more thermal dissipation effectively. (2) There is little surface temperature between artificial grass and concrete. But there is little high surface temperature difference between natural grass and concrete because of latent heat effect. (3) The concrete can play a role of the tropical nights phenomenon as high heat capacity of concrete compare with other materials. (4) It is nearly same color in artificial grass and natural grass but there is large difference between natural grass and artificial grass at albedo. There is different albedo in near infrared ray range. (5) A short wave radiation gives more effect at the globe temperature than long wave radiation. (6) The artificial turf protected the slab surface temperature increase in spite of thin and low albedo materials.

Mitigating the Urban Heat Island Phenomenon Using a Water-Retentive Artificial Turf System

  • Tebakari, Taichi;Maruyama, Tatsuya;Inui, Masahiro
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.91-100
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    • 2010
  • To investigate the thermal properties of a water-retentive artificial turf system (W-ATS), we estimated hydrologic parameters including thermal conductivity, heat capacity, and surface albedo for both the W-ATS and natural grass. We used a model experiment to measure surface temperature and evaporation for both the W-ATS and natural grass. We found that the W-ATS had lower thermal conductivity than natural grass did, and it was difficult for the W-ATS to convey radiant heat to the ground. Compared to natural grass, the W-ATS also had lower heat capacity, which contributed to its larger variation in surface temperature: the W-ATS had higher surface temperatures during daytime and lower surface temperatures during nighttime. The albedo of the W-ATS was one-quarter that of natural grass, and reflected shortwave radiation from the W-ATS surface was lower than that from the surface of natural grass. These results indicate that the W-ATS caused the soil temperature to increase. Furthermore, evaporation from the W-ATS was one-quarter the value of evapotranspiration from natural grass.

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A Study on the Influence of Urban Environment on the Generation of Thermal Diseases (도시 환경이 온열질환 발생에 미치는 영향에 관한 연구)

  • Lee, Su-Mi;Kweon, Ihl;Kim, Yong-Jin
    • The Journal of the Korea Contents Association
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    • v.19 no.12
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    • pp.84-92
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    • 2019
  • The deterioration of the urban heat environment due to climate change and the occurrence of heat-related diseases have emerged as one of the major social problems. This has led to more research on climate change, including heat waves, but it is mainly focused on climate factors. However, the urban heat island phenomenon accelerates the summer heat wave, and the increasing trend of heat-related patients in urban areas suggests the impact of the city's environment. Thus, this study analyzed the effects of physical and social characteristics of urban areas on heat-related patients in Seoul and Gyeonggi-do. The analysis showed that the ratio of the total area of residential, commercial and industrial facilities, the main source of heat energy locality, among the land use statuses, was not statistically significant, but the road area and the green area were found to have a positive and negative The population density and the percentage of people aged 65 or older, the percentage of people living alone and the proportion of people receiving basic living were all shown to be significant, with only the ratio of elderly living alone and the ratio of population density having negative effects. The results of the study can be used to develop urban policy alternatives related to local warming patients.

Influences of Urban Trees on the Control of the Temperature (도시의 수목이 기온의 조절에 미치는 영향)

  • 김수봉;김해동
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.3
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    • pp.25-34
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    • 2002
  • The purpose of this paper is to discuss the function of microclimate amelioration of urban trees regarding the environmental benefits of street trees in summer, focusing on the heat pollution-urban heat island, tropical climate day's phenomenon and air pollution. We measured the diurnal variation of air/ground temperatures and humidity within the vegetation canopy with the meteorological tower observation system. Summertime air temperatures within the vegetation canopy layer were 1-2$^{\circ}C$ cooler than in places with no vegetation. Due to lack of evaporation, the ground surface temperatures of footpaths were, at a midafternoon maximum, 8$^{\circ}C$ hotter than those under trees. This means that heat flows from a place with no vegetation to a vegetation canopy layer during the daytime. The heat is consumed as a evaporation latent heat. These results suggest that the extension of vegetation canopy bring about a more pleasant urban climate. Diurnal variation of air/ground temperatures and humidity within the vegetation canopy were measured with the meteorological tower observation system. According to the findings, summertime air temperatures under a vegetation canopy layer were 1-2$^{\circ}C$ cooler than places with no vegetation. Due mainly to lack of evaporation the ground surface temperature of footpaths were up to 8$^{\circ}C$ hotter than under trees during mid-afternoon. This means that heat flows from a place where there is no vegetation to another place where there is a vegetation canopy layer during the daytime. Through the energy redistribution analysis, we ascertain that the major part of solar radiation reaching the vegetation cover is consumed as a evaporation latent heat. This result suggests that the expansion of vegetation cover creates a more pleasant urban climate through the cooling effect in summer. Vegetation plays an important role because of its special properties with energy balance. Depended on their evapotranspiration, vegetation cover and water surfaces diminish the peaks of temperature during the day. The skill to make the best use of the vegetation effect in urban areas is a very important planning device to optimize urban climate. Numerical simulation study to examine the vegetation effects on urban climate will be published in our next research paper.