---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '22517'
abstract:
- lang: eng
  text: The capacity of vegetation to mitigate excessive urban heat has been well
    documented. However, the cooling potential provided by urban vegetation during
    heatwaves is less known even though heatwaves have been projected to be more severe
    with climate change. Across 24 global metropolises, we combine 30 m resolution
    satellite observations with a theoretical leaf energy balance model to quantify
    the change of the leaf-to-air temperature difference and stomatal conductance
    during heatwaves from 2000 to 2020. We found the responses of urban vegetation
    to heatwaves differ significantly across cities and they are mediated by climate
    forcing and human management. During heatwaves, vegetation in Mediterranean and
    midlatitude-humid cities shows a significant decrease in cooling potential in
    most cases due to large stomatal closures, while vegetation in arid cities shows
    a cooling enhancement with an unmodified stomatal opening likely in response to
    intense irrigation. In comparison, the cooling potential of vegetation in high-latitude
    humid cities does not show significant changes. These responses have implications
    for future urban vegetation management strategies and urban planning.
article_number: '014035'
article_processing_charge: No
article_type: letter_note
author:
- first_name: Jiacheng
  full_name: Zhao, Jiacheng
  last_name: Zhao
- first_name: Naika
  full_name: Meili, Naika
  last_name: Meili
- first_name: Xiang
  full_name: Zhao, Xiang
  last_name: Zhao
- first_name: Simone
  full_name: Fatichi, Simone
  id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
  last_name: Fatichi
citation:
  ama: Zhao J, Meili N, Zhao X, Fatichi S. Urban vegetation cooling potential during
    heatwaves depends on background climate. <i>Environmental Research Letters</i>.
    2023;18(1). doi:<a href="https://doi.org/10.1088/1748-9326/acaf0f">10.1088/1748-9326/acaf0f</a>
  apa: Zhao, J., Meili, N., Zhao, X., &#38; Fatichi, S. (2023). Urban vegetation cooling
    potential during heatwaves depends on background climate. <i>Environmental Research
    Letters</i>. IOP Publishing. <a href="https://doi.org/10.1088/1748-9326/acaf0f">https://doi.org/10.1088/1748-9326/acaf0f</a>
  chicago: Zhao, Jiacheng, Naika Meili, Xiang Zhao, and Simone Fatichi. “Urban Vegetation
    Cooling Potential during Heatwaves Depends on Background Climate.” <i>Environmental
    Research Letters</i>. IOP Publishing, 2023. <a href="https://doi.org/10.1088/1748-9326/acaf0f">https://doi.org/10.1088/1748-9326/acaf0f</a>.
  ieee: J. Zhao, N. Meili, X. Zhao, and S. Fatichi, “Urban vegetation cooling potential
    during heatwaves depends on background climate,” <i>Environmental Research Letters</i>,
    vol. 18, no. 1. IOP Publishing, 2023.
  ista: Zhao J, Meili N, Zhao X, Fatichi S. 2023. Urban vegetation cooling potential
    during heatwaves depends on background climate. Environmental Research Letters.
    18(1), 014035.
  mla: Zhao, Jiacheng, et al. “Urban Vegetation Cooling Potential during Heatwaves
    Depends on Background Climate.” <i>Environmental Research Letters</i>, vol. 18,
    no. 1, 014035, IOP Publishing, 2023, doi:<a href="https://doi.org/10.1088/1748-9326/acaf0f">10.1088/1748-9326/acaf0f</a>.
  short: J. Zhao, N. Meili, X. Zhao, S. Fatichi, Environmental Research Letters 18
    (2023).
das_tickbox: '1'
date_created: 2026-07-27T12:30:24Z
date_published: 2023-01-12T00:00:00Z
date_updated: 2026-08-06T11:33:12Z
day: '12'
doi: 10.1088/1748-9326/acaf0f
extern: '1'
fulldoi: https://doi.org/10.1088/1748-9326/acaf0f
intvolume: '        18'
issue: '1'
keyword:
- Urban vegetation
- Heatwave
- Cooling potential
- Stomatal behavior
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
main_file_link:
- open_access: '1'
  url: https://doi.org/0.1088/1748-9326/acaf0f
month: '01'
oa: 1
oa_version: Published Version
publication: Environmental Research Letters
publication_identifier:
  eissn:
  - 1748-9326
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Urban vegetation cooling potential during heatwaves depends on background climate
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 18
year: '2023'
...
---
OA_type: closed access
_id: '22561'
abstract:
- lang: eng
  text: "Urban tree planting is an effective strategy to reduce temperature locally
    and eventually mitigate Urban Heat\r\nIsland. Although its cooling effects have
    been widely reported, understanding of coupling effects of street\r\nmorphologies
    and tree characteristics on thermal environment is insufficient, especially in
    high-density cities. A\r\nparametric study is conducted to investigate effects
    of leaf area index (LAI = 1.0,2.0,3.0,4.0,5.0,6.0) and tree\r\ncrown radius (rtree
    = 2.0,3.4,4.4,5.0 m) on thermal environment inside streets with various aspect
    ratios (street\r\nheight/width, H/W = 1.0–5.0). A mechanistic urban canopy model
    Urban Tethys-Chloris (UT&C) is selected and\r\nintegrated with a new semi-empirical
    wind parameterization based on drag coefficients and frontal area densities\r\nof
    buildings and trees. Modified UT&C is validated by a unique and controllable scaled
    outdoor experiment. The\r\nresearch outputs can be summarized as follows: (1)
    Calculated air temperature (Ta), wind speed (V), and thermal\r\ncomfort indices
    (Mean Radiant Temperature (Tmrt) and Universal Thermal Climate Index (UTCI)) are
    in good\r\nagreement with results from scaled outdoor experiments, while slight
    overestimation of relative humidity (RH)\r\noccurs in tree cases; (2) Increasing
    LAI and rtree both bring stronger cooling effects by up to 20.2 ◦C (Tmrt) and\r\n4.0
    ◦C (UTCI); (3) Narrower streets weaken trees’ cooling effects and increasing LAI
    and rtree could be less\r\nefficient for higher H/W than lower H/W; (4) LAI =
    4.0 and rtree = 5.0 m are optimal for wide streets (H/W =\r\n1.0–3.0) to provide
    maximum UTCI cooling (about 4.0 ◦C), while LAI = 4.0 and rtree = 3.4 m are suggested
    for\r\nnarrow streets (H/W = 3.0–5.0). Our study provides useful information on
    evidence-based urban tree selection\r\nstrategies for urban planning and design. "
article_number: '111006'
article_processing_charge: No
article_type: original
author:
- first_name: Taihan
  full_name: Chen, Taihan
  last_name: Chen
- first_name: Naika
  full_name: Meili, Naika
  last_name: Meili
- first_name: Simone
  full_name: Fatichi, Simone
  id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
  last_name: Fatichi
- first_name: Jian
  full_name: Hang, Jian
  last_name: Hang
- first_name: Puay Yok
  full_name: Tan, Puay Yok
  last_name: Tan
- first_name: Chao
  full_name: Yuan, Chao
  last_name: Yuan
citation:
  ama: Chen T, Meili N, Fatichi S, Hang J, Tan PY, Yuan C. Effects of tree plantings
    with varying street aspect ratios on the thermal environment using a mechanistic
    urban canopy model. <i>Building and Environment</i>. 2023;246. doi:<a href="https://doi.org/10.1016/j.buildenv.2023.111006">10.1016/j.buildenv.2023.111006</a>
  apa: Chen, T., Meili, N., Fatichi, S., Hang, J., Tan, P. Y., &#38; Yuan, C. (2023).
    Effects of tree plantings with varying street aspect ratios on the thermal environment
    using a mechanistic urban canopy model. <i>Building and Environment</i>. Elsevier.
    <a href="https://doi.org/10.1016/j.buildenv.2023.111006">https://doi.org/10.1016/j.buildenv.2023.111006</a>
  chicago: Chen, Taihan, Naika Meili, Simone Fatichi, Jian Hang, Puay Yok Tan, and
    Chao Yuan. “Effects of Tree Plantings with Varying Street Aspect Ratios on the
    Thermal Environment Using a Mechanistic Urban Canopy Model.” <i>Building and Environment</i>.
    Elsevier, 2023. <a href="https://doi.org/10.1016/j.buildenv.2023.111006">https://doi.org/10.1016/j.buildenv.2023.111006</a>.
  ieee: T. Chen, N. Meili, S. Fatichi, J. Hang, P. Y. Tan, and C. Yuan, “Effects of
    tree plantings with varying street aspect ratios on the thermal environment using
    a mechanistic urban canopy model,” <i>Building and Environment</i>, vol. 246.
    Elsevier, 2023.
  ista: Chen T, Meili N, Fatichi S, Hang J, Tan PY, Yuan C. 2023. Effects of tree
    plantings with varying street aspect ratios on the thermal environment using a
    mechanistic urban canopy model. Building and Environment. 246, 111006.
  mla: Chen, Taihan, et al. “Effects of Tree Plantings with Varying Street Aspect
    Ratios on the Thermal Environment Using a Mechanistic Urban Canopy Model.” <i>Building
    and Environment</i>, vol. 246, 111006, Elsevier, 2023, doi:<a href="https://doi.org/10.1016/j.buildenv.2023.111006">10.1016/j.buildenv.2023.111006</a>.
  short: T. Chen, N. Meili, S. Fatichi, J. Hang, P.Y. Tan, C. Yuan, Building and Environment
    246 (2023).
das_tickbox: '1'
date_created: 2026-07-27T12:30:24Z
date_published: 2023-12-01T00:00:00Z
date_updated: 2026-08-12T08:37:07Z
day: '01'
doi: 10.1016/j.buildenv.2023.111006
extern: '1'
fulldoi: https://doi.org/10.1016/j.buildenv.2023.111006
intvolume: '       246'
keyword:
- Urban canopy model
- Scaled outdoor experiment
- Street aspect ratio
- Urban vegetation
- Pedestrian thermal comfort
language:
- iso: eng
month: '12'
oa_version: None
publication: Building and Environment
publication_identifier:
  eissn:
  - 1873-684X
  issn:
  - 0360-1323
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: Effects of tree plantings with varying street aspect ratios on the thermal
  environment using a mechanistic urban canopy model
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 246
year: '2023'
...