---
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'
...
---
OA_place: publisher
OA_type: hybrid
_id: '22457'
abstract:
- lang: eng
  text: "An increase in urban vegetation is an often proposed mitigation strategy
    to reduce urban heat and improve outdoor thermal comfort (OTC). Vegetation can
    alter urban microclimate through changes in air temperature, mean radiant temperature,
    humidity, and wind speed. In this study, we model how street tree and ground vegetation
    cover and their structural, optical, interception, and physiological traits control
    the diurnal cycle of OTC in different urban densities in a tropical city (Singapore).
    For this purpose, we perform a variance based sensitivity analysis of the urban
    ecohydrological model UT&C. Model performance is evaluated through a comparison
    with local microclimate measurements and OTC is assessed with the Universal Thermal
    Climate Index (UTCI).\r\nWe find a pronounced daily cycle of vegetation effects
    on UTCI. Tree cover fraction is more efficient in decreasing UTCI during daytime,
    while a higher vegetated ground fraction provides more cooling during night. Generally,
    increasing vegetation cover fractions do not deter OTC, except in certain urban
    densities during some periods of the day. An increase in tree and ground vegetation
    fractions provides a higher average UTCI reduction compared to a change in vegetation
    traits (0.9 – 2.9  °C vs. 0.7 – 1.1  °C during midday, 10 month average). The
    increase in humidity related to plant transpiration prevents further reduction
    of UTCI. However, the choice of vegetation traits enhancing tree transpiration
    can decrease UTCI during hot periods. These results can inform urban planners
    on the selection of vegetation amount and traits to achieve feasible OTC improvements
    in tropical cities."
article_number: '107733'
article_processing_charge: No
article_type: original
author:
- first_name: Naika
  full_name: Meili, Naika
  last_name: Meili
- first_name: Juan Angel
  full_name: Acero, Juan Angel
  last_name: Acero
- first_name: Nadav
  full_name: Peleg, Nadav
  last_name: Peleg
- first_name: Gabriele
  full_name: Manoli, Gabriele
  last_name: Manoli
- first_name: Paolo
  full_name: Burlando, Paolo
  last_name: Burlando
- first_name: Simone
  full_name: Fatichi, Simone
  id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
  last_name: Fatichi
citation:
  ama: Meili N, Acero JA, Peleg N, Manoli G, Burlando P, Fatichi S. Vegetation cover
    and plant-trait effects on outdoor thermal comfort in a tropical city. <i>Building
    and Environment</i>. 2021;195. doi:<a href="https://doi.org/10.1016/j.buildenv.2021.107733">10.1016/j.buildenv.2021.107733</a>
  apa: Meili, N., Acero, J. A., Peleg, N., Manoli, G., Burlando, P., &#38; Fatichi,
    S. (2021). Vegetation cover and plant-trait effects on outdoor thermal comfort
    in a tropical city. <i>Building and Environment</i>. Elsevier. <a href="https://doi.org/10.1016/j.buildenv.2021.107733">https://doi.org/10.1016/j.buildenv.2021.107733</a>
  chicago: Meili, Naika, Juan Angel Acero, Nadav Peleg, Gabriele Manoli, Paolo Burlando,
    and Simone Fatichi. “Vegetation Cover and Plant-Trait Effects on Outdoor Thermal
    Comfort in a Tropical City.” <i>Building and Environment</i>. Elsevier, 2021.
    <a href="https://doi.org/10.1016/j.buildenv.2021.107733">https://doi.org/10.1016/j.buildenv.2021.107733</a>.
  ieee: N. Meili, J. A. Acero, N. Peleg, G. Manoli, P. Burlando, and S. Fatichi, “Vegetation
    cover and plant-trait effects on outdoor thermal comfort in a tropical city,”
    <i>Building and Environment</i>, vol. 195. Elsevier, 2021.
  ista: Meili N, Acero JA, Peleg N, Manoli G, Burlando P, Fatichi S. 2021. Vegetation
    cover and plant-trait effects on outdoor thermal comfort in a tropical city. Building
    and Environment. 195, 107733.
  mla: Meili, Naika, et al. “Vegetation Cover and Plant-Trait Effects on Outdoor Thermal
    Comfort in a Tropical City.” <i>Building and Environment</i>, vol. 195, 107733,
    Elsevier, 2021, doi:<a href="https://doi.org/10.1016/j.buildenv.2021.107733">10.1016/j.buildenv.2021.107733</a>.
  short: N. Meili, J.A. Acero, N. Peleg, G. Manoli, P. Burlando, S. Fatichi, Building
    and Environment 195 (2021).
das_tickbox: '1'
date_created: 2026-07-27T12:30:23Z
date_published: 2021-05-01T00:00:00Z
date_updated: 2026-07-30T09:12:50Z
day: '01'
ddc:
- '550'
doi: 10.1016/j.buildenv.2021.107733
extern: '1'
fulldoi: https://doi.org/10.1016/j.buildenv.2021.107733
has_accepted_license: '1'
intvolume: '       195'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1016/j.buildenv.2021.107733
month: '05'
oa: 1
oa_version: Published Version
publication: Building and Environment
publication_identifier:
  issn:
  - 0360-1323
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: Vegetation cover and plant-trait effects on outdoor thermal comfort in a tropical
  city
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: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 195
year: '2021'
...