Journal of the Korean Institute of Landscape Architecture (한국조경학회지)

The Korean Institute of Landscape Architecture (한국조경학회)
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Analysis of the Influence of Street Trees on Human Thermal Sensation in Summer

여름철 인간 열환경지수에 미치는 가로수의 영향 분석

  • Jo, Sang-man (Graduate School of Horticultural Science, College of Applied Life Science, Jeju National University) ;
  • Hyun, Cheol-ji (Graduate School of Horticultural Science, College of Applied Life Science, Jeju National University) ;
  • Park, Soo-kuk (Research Institute for Subtropical Agriculture and Animal Biotechnology, SARI, Horticultural Science, College of Applied Life Science, Jeju National University)
  • 조상만 (제주대학교 생명자원과학대학 원예학과 대학원) ;
  • 현철지 (제주대학교 생명자원과학대학 원예학과 대학원) ;
  • 박수국 (제주대학교 생명자원과학대학 생물산업학부 원예환경전공.아열대농업생명과학연구소.친환경농업연구소)
  • Received : 2017.07.28
  • Accepted : 2017.10.25
  • Published : 2017.10.31
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Abstract

In order to analyze the effect of street trees on human thermal sensation(thermal comfort) in summer, microclimatic data were measured and analyzed at sunny and shaded locations of two deciduous broadleaf and three broadleaf evergreen species of street trees. As a result, the mean differences by species in air temperature, relative humidity and wind speed were small: $0.2{\sim}1.5^{\circ}C$, 0.9~5.3% and $0.1{\sim}0.5 ms^{-1}$, respectively, but the mean difference in the mean radiant temperature was great, $27.1^{\circ}C$. In the results of physiological equivalent temperature(PET) and universal thermal climate index(UTCI), which are human thermal sensation(thermal comfort) indexes, the shaded locations by the trees showed mean reduction rates of 21.2~31.3% in the PET compared with the sunny location, which are equivalent to 1.5~2.5 levels of thermal perception. Also, 12.7~20.0% in the UTCI was reduced by the trees' shadows, which is equivalent to 1~1.5 levels of heat stress. In addition, although the broadleaf evergreen trees had 5% greater mean reduction in PET than that of the deciduous broadleaf trees, the Zelkova serrata that belonged to the deciduous broadleaf trees showed the equivalent thermal reduction effect as the broadleaf evergreen trees because of the high density of branches and leaves. Therefore, the mean radiant temperature and the density of the crown(branches and leaves) were the main influences in thermal modification by these street trees in summer.

가로수가 여름철 인간 열환경지수(열쾌적성)에 미치는 영향을 분석하기 위해, 낙엽활엽교목 2종과 상록활엽교목 3종 총 5종의 가로수를 대상으로 수목 하부의 음지와 그 옆의 양지에서 미기후 자료를 측정하여 비교 분석하였다. 그 결과, 기온, 상대습도, 풍속의 차이는 각각 평균 $0.2{\sim}1.5^{\circ}C$, 0.9~5.3%, $0.1{\sim}0.5ms^{-1}$로 미비하였으나, 평균복사온도는 평균 $27.1^{\circ}C$의 매우 큰 차이를 보여 주었다. 인간 열환경지수인 PET와 UTCI 결과에서는 수목 하부의 음지가 양지에 비해 PET에서는 평균 21.2~31.3%의 저감 비율을 보여 1.5~2.5단계의 열지각 개선 효과를 나타내었으며, UTCI에서는 평균 12.7~20.0%의 저감 비율을 보여 1~1.5단계의 heat stress 저감 효과를 보이는 것으로 나타났다. 또한, 상록활엽교목이 낙엽활엽교목에 비해 PET에서 평균 5% 더 높은 저감 비율을 나타냈지만, 낙엽활엽교목에 속하는 느티나무는 지엽의 밀도가 높아 상록활엽교목 만큼의 열환경지수(열쾌적성) 개선 효과를 나타내었다. 이에 따라, 가로수의 여름철 열 저감 효과에서 지엽의 밀도와 평균복사온도가 주요 영향임을 알 수 있었다.

Keywords

References

  1. Abreu-Harbich, L., L. Labaki and A. Matzarakis(2015) Effect of tree planting design and tree species on human thermal comfort in the tropics. Landscape and Urban Planning 138: 99-109. https://doi.org/10.1016/j.landurbplan.2015.02.008
  2. Ahn, T., J. Lee, Kim. B, Yoon, S. Son, Y. Choi, N. Lee, J. Lee and H. Kim(2013) An analysis of thermal comforts for pedestrians by WBGT measurement on the urban street greens. Journal of Korean Institute of Landscape Architecture 41(3): 22-30. https://doi.org/10.9715/KILA.2013.41.3.022
  3. Choi, D. and B. Lee(2006) Analysis of passive cooling effect of the tree by field observations in the summer. Journal of the Korean Solar Energy Society 26(4): 109-110.
  4. Egerhazi, L. A., A. Kovacs and J. Unger(2013) Application of microclimate modeling and onsite survey in planning practice related to an urban micro-environment. Advances in Meteorology 2013, Article ID 251586, doi: http://dx.doi.org/10.1155/2013/251586
  5. Gal, T., M. Rzepa, B. Gromek and J. Unger(2007) Comparison between sky view factor values computed by two different methods in an urban environment. ACTA Climatologica et Chrologica, Universitatis Szegediensis, Tomus 40-41: 17-26.
  6. IPCC(2013) Climate Change 2013: The Physical Science Basis. WMO, 7bis, Avenue de la Paix, 1211 Geneva2.
  7. Ju, M., C. Lee and N. Ryu(2004) The effect of urban shade trees on the WBGT (Wet Bulb Globe Thermometer Index). Journal of the Korean Institute of Landscape Architecture 32(3): 51-59.
  8. Jung, L., Y. Jin, Y. Jeun, K. Ko, H. Park and S. Park(2016) A case study of human thermal sensation (comfort) in plastic houses. Journal of Environmental Science International 25(8): 1115-1129. https://doi.org/10.5322/JESI.2016.25.8.1115
  9. Lee, C. and N. Ryu(2010) The influence of landscape pavements on the WBGT of outdoor spaces without ventilation or shade at summer midday. Journal of the Korean Institute of Landscape Architecture 38(2): 1-8.
  10. Lee, C. and N. Ryu(2012) The influence of ventilation and shade on the mean radiant temperature of summer outdoor. Journal of the Korean Institute of Landscape Architecture 40(5): 100-108. https://doi.org/10.9715/KILA.2012.40.5.100
  11. Lee, C. and N. Ryu(2013) The comparison of the ultra-violet radiation of summer outdoor screened by the landscaping shade facilities and tree. Journal of the Korean Institute of Landscape Architecture 41(6): 20-28. https://doi.org/10.9715/KILA.2013.41.6.020
  12. Lee, C. and N. Ryu(2014) The comparison of the solar radiation and the mean radiant temperature (MRT) urban the shade of landscaping trees in summertime. Journal of the Korean Institute of Landscape Architecture 42(5): 22-30. https://doi.org/10.9715/KILA.2014.42.5.022
  13. Matzarakis, A., F. Rutz and H. Mayer(2010) Modelling radiation fluxes in simple and complex environments: Basics of the RayMan Model. International Journal of Biometeorology 54(2): 131-139. https://doi.org/10.1007/s00484-009-0261-0
  14. Park, K., S. Lee, Y. Shim and H. Hwang(2011) Analysis on the mitigation effects of urban heat island through creation of water space-a case study of Yeol-Mae village Apt in Daejeon's Noeun District. The International Journal of the Korean Institute of Ecological Architecture and Environment 11(5): 13-18.
  15. Park, S.(2011) Human-Urban Radiation Exchange Simulation Model. Ph.D dissertation, University of Victoria, Victoria, B.C., Canada.
  16. Park, S.(2012) Landscape planning and design methods with human thermal sensation. Journal of the Korean Institute of Landscape Architecture 40(1): 1-11. https://doi.org/10.9715/KILA.2012.40.1.001
  17. Park, S.(2013) A way for creating human bioclimatic maps using human thermal sensation (comfort) and applying the maps to urban and landscape planning and design. Journal of the Korean Institute of Landscape Architecture 41(1): 21-33. https://doi.org/10.9715/KILA.2013.41.1.021
  18. Shahidan, M., M. Shariff, P. Jones, E. Salleh and A. Abdullah (2010) A comparisonof Mesua ferrea L. and Hura crepitans L. for shade creation and radiation modification in improving thermal comfort. Landscape and Urban Planning 97: 168-181. https://doi.org/10.1016/j.landurbplan.2010.05.008
  19. Takacs, A., M. Kiss, A. Hof, E. Tanacs, A. Gulyas and N. Kantor (2016) Microclimate modification by urban shade trees: An integrated approach to aid ecosystem service based decision making. Procedia Environmental Sciences 32: 97-109. https://doi.org/10.1016/j.proenv.2016.03.015
  20. Thorsson, S., F. Lindberg, I. Eliasson and B. Holmer(2007) Different methods for estimating the mean radiant temperature in an outdoor urban setting. International Journal of Climatology 27: 1983-1993. https://doi.org/10.1002/joc.1537
  21. Yoon, Y.(2003) Temperature lowering effects varied by the arrangement and types of vegetation. Journal of Korean Turfgrass Science 17(4): 165-172.
  22. Yoon, Y., S. Park, W. Kim and J. Kim(2014) Analyses on comparison of UTCI, PMV, WBGT between playground and green space in school. Journal of Korean Environment and Ecology 28(1): 80-89. https://doi.org/10.13047/KJEE.2014.28.1.80