Journal of Integrative Agriculture ›› 2013, Vol. 12 ›› Issue (8): 1307-1315.DOI: 10.1016/S2095-3119(13)60543-2

• 论文 • 上一篇    下一篇

Effects of Evapotranspiration on Mitigation of Urban Temperature by Vegetation and Urban Agriculture

 QIU Guo-yu, LI Hong-yong, ZHANG Qing-tao, CHEN Wan, LIANG Xiao-jian , LI Xiang-ze   

  1. Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, P.R.China
  • 收稿日期:2013-10-17 出版日期:2013-08-01 发布日期:2013-09-12
  • 通讯作者: Correspondence QIU Guo-yu, Tel: +86-755-26033309, E-mail: qiugy@pkusz.edu.cn
  • 基金资助:

    This research is partially supported by the Special Fund for Forestry Research in the Public Interest (201304305), the National 973 Program of China (2009CB825103), and the Shenzhen Science and Technology Project (ZYC201006170373A).

Effects of Evapotranspiration on Mitigation of Urban Temperature by Vegetation and Urban Agriculture

 QIU Guo-yu, LI Hong-yong, ZHANG Qing-tao, CHEN Wan, LIANG Xiao-jian , LI Xiang-ze   

  1. Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, P.R.China
  • Received:2013-10-17 Online:2013-08-01 Published:2013-09-12
  • Contact: Correspondence QIU Guo-yu, Tel: +86-755-26033309, E-mail: qiugy@pkusz.edu.cn
  • Supported by:

    This research is partially supported by the Special Fund for Forestry Research in the Public Interest (201304305), the National 973 Program of China (2009CB825103), and the Shenzhen Science and Technology Project (ZYC201006170373A).

摘要: The temperature difference between an urban space and surrounding non-urban space is called the urban heat island effect (UHI). Global terrestrial evapotranspiration (ET) can consume 1.4803×1023 joules (J) of energy annually, which is about 21.74% of the total available solar energy at the top of atmosphere, whereas annual human energy use is 4.935×1020 J, about 0.33% of annual ET energy consumption. Vegetation ET has great potential to reduce urban and global temperatures. Our literature review suggests that vegetation and urban agricultural ET can reduce urban temperatures by 0.5 to 4.0°C. Green roofs (including urban agriculture) and water bodies have also been shown to be effective ways of reducing urban temperatures. The cooling effects on the ambient temperature and the roof surface temperature can be 0.24-4.0°C and 0.8-60.0°C, respectively. The temperature of a water body (including urban aquaculture) can be lower than the temperature of the surrounding built environment by between 2 and 6°C, and a water body with a 16 m2 surface area can cool up to 2 826 m3 of nearby space by 1°C. Based on these findings, it can be concluded that the increase of evapotranspiration in cities, derived from vegetation, urban agriculture, and water body, can effectively mitigate the effect of urban heat islands.

关键词: evapotranspiration , urban heat island , vegetation , temperature

Abstract: The temperature difference between an urban space and surrounding non-urban space is called the urban heat island effect (UHI). Global terrestrial evapotranspiration (ET) can consume 1.4803×1023 joules (J) of energy annually, which is about 21.74% of the total available solar energy at the top of atmosphere, whereas annual human energy use is 4.935×1020 J, about 0.33% of annual ET energy consumption. Vegetation ET has great potential to reduce urban and global temperatures. Our literature review suggests that vegetation and urban agricultural ET can reduce urban temperatures by 0.5 to 4.0°C. Green roofs (including urban agriculture) and water bodies have also been shown to be effective ways of reducing urban temperatures. The cooling effects on the ambient temperature and the roof surface temperature can be 0.24-4.0°C and 0.8-60.0°C, respectively. The temperature of a water body (including urban aquaculture) can be lower than the temperature of the surrounding built environment by between 2 and 6°C, and a water body with a 16 m2 surface area can cool up to 2 826 m3 of nearby space by 1°C. Based on these findings, it can be concluded that the increase of evapotranspiration in cities, derived from vegetation, urban agriculture, and water body, can effectively mitigate the effect of urban heat islands.

Key words: evapotranspiration , urban heat island , vegetation , temperature