Figure 1.
The range of research area. The red dashed box formed by ABCD represents the study area for this research.
Figure 1.
The range of research area. The red dashed box formed by ABCD represents the study area for this research.
Figure 2.
Daily temperature data of downtown Los Angeles in 2022.
Figure 2.
Daily temperature data of downtown Los Angeles in 2022.
Figure 3.
With or without tree in date comparison diagram. The green area indicates the locations of trees in the simulation.
Figure 3.
With or without tree in date comparison diagram. The green area indicates the locations of trees in the simulation.
Figure 4.
Tree under the shade of building’s simulation diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 4.
Tree under the shade of building’s simulation diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 5.
Tree’s eight location’s simulation diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 5.
Tree’s eight location’s simulation diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 6.
Trees’ canopies separated by 15-feet diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 6.
Trees’ canopies separated by 15-feet diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 7.
Trees touching canopies diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 7.
Trees touching canopies diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 8.
Overlapping trees’ canopies diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 8.
Overlapping trees’ canopies diagram. The green area indicates the locations of trees in the simulation. The gray area represents the locations of buildings in the simulation.
Figure 9.
No tree and one tree modeling in ENVI-met.
Figure 9.
No tree and one tree modeling in ENVI-met.
Figure 10.
Hottest day UTCI diagram comparison by date factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 10.
Hottest day UTCI diagram comparison by date factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 11.
Coldest day UTCI diagram comparison by date factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 11.
Coldest day UTCI diagram comparison by date factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 12.
Hottest and coldest days reduced UTCI comparison (center of the tree).
Figure 12.
Hottest and coldest days reduced UTCI comparison (center of the tree).
Figure 13.
Hottest and coldest days reduced UTCI comparison (shadow area of the tree).
Figure 13.
Hottest and coldest days reduced UTCI comparison (shadow area of the tree).
Figure 14.
Each month reduced UTCI comparison.
Figure 14.
Each month reduced UTCI comparison.
Figure 15.
Building shade without a tree and with a tree.
Figure 15.
Building shade without a tree and with a tree.
Figure 16.
Hottest day UTCI diagram comparison by building shade factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 16.
Hottest day UTCI diagram comparison by building shade factor at 10 a.m., 12 p.m., and 2 p.m.
Figure 17.
Cooling ability reduction comparison.
Figure 17.
Cooling ability reduction comparison.
Figure 18.
Building shade without a tree and with a tree for transpiration analysis.
Figure 18.
Building shade without a tree and with a tree for transpiration analysis.
Figure 19.
Hottest day UTCI diagram comparison by transpiration factor at 10 a.m.
Figure 19.
Hottest day UTCI diagram comparison by transpiration factor at 10 a.m.
Figure 20.
Coldest day UTCI diagram comparison by transpiration factor at 10 a.m.
Figure 20.
Coldest day UTCI diagram comparison by transpiration factor at 10 a.m.
Figure 21.
Transpiration cooling effect on UTCI comparison.
Figure 21.
Transpiration cooling effect on UTCI comparison.
Figure 22.
Trees in different eight locations surrounding a building diagram.
Figure 22.
Trees in different eight locations surrounding a building diagram.
Figure 23.
Hottest day sunrise, noon, and sunset time UTCI comparison (8 a.m., 12 p.m., and 5 p.m.).
Figure 23.
Hottest day sunrise, noon, and sunset time UTCI comparison (8 a.m., 12 p.m., and 5 p.m.).
Figure 24.
Hottest day building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 24.
Hottest day building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 25.
Coldest day building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 25.
Coldest day building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 26.
Whole-year building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 26.
Whole-year building shadow analysis. The green area indicates the locations of trees in the simulation. The dark gray area represents the locations of buildings in the simulation. The shaded area represents the extent of building shadow coverage. The darker the shade, the longer the duration of the building’s shadow coverage.
Figure 27.
Trees’ best cooling location ranking.
Figure 27.
Trees’ best cooling location ranking.
Figure 28.
Three types of trees’ spacing UTCI comparison at 12 pm (hottest day).
Figure 28.
Three types of trees’ spacing UTCI comparison at 12 pm (hottest day).
Figure 29.
New trees’ layout 3D map.
Figure 29.
New trees’ layout 3D map.
Figure 30.
Full-site new trees’ 3D model in ENVI-met.
Figure 30.
Full-site new trees’ 3D model in ENVI-met.
Figure 31.
Full-site no trees’ UTCI diagram.
Figure 31.
Full-site no trees’ UTCI diagram.
Figure 32.
Full-site existing trees’ UTCI diagram.
Figure 32.
Full-site existing trees’ UTCI diagram.
Figure 33.
Full-site new trees’ UTCI diagram.
Figure 33.
Full-site new trees’ UTCI diagram.
Figure 34.
Full-site pedestrian area UTCI comparisons at 12 p.m.
Figure 34.
Full-site pedestrian area UTCI comparisons at 12 p.m.
Figure 35.
Reduced UTCI for each month (new scheme).
Figure 35.
Reduced UTCI for each month (new scheme).
Table 1.
Species of trees in the full-site study area.
Table 1.
Species of trees in the full-site study area.
Canopy Size | Tree Types | Quantity |
---|
Large | Cylindric, small trunk, sparse, 25 m | 8 |
Spherical, large trunk, dense, 15 m | 2 |
Medium | Spherical, medium trunk, dense, 15 m | 18 |
Spherical, small trunk, dense, 15 m | 5 |
Spherical, small trunk, sparse, 15 m | 4 |
Small | Spherical, medium trunk, dense, 5 m | 31 |
Spherical, small trunk, dense, 5 m | 20 |
Spherical, medium trunk, sparse, 5 m | 4 |
Table 2.
UTCI thermal comfort standard.
Table 2.
UTCI thermal comfort standard.
UTCI (°C) | Stress Category |
---|
UTCI > 46 | Extreme heat stress |
38 < UTCI ≤ 46 | Very strong heat stress |
32 < UTCI ≤ 38 | Strong heat stress |
26 < UTCI ≤ 32 | Moderate heat stress |
9 < UTCI ≤ 26 | No thermal stress |
0 < UTCI ≤ 9 | Slight cold stress |
−13 < UTCI ≤ 0 | Moderate cold stress |
−27 < UTCI ≤ −13 | Strong cold stress |
−40 < UTCI ≤ −27 | Very strong cold stress |
UTCI ≤ −40 | Extreme cold stress |
Table 3.
Full-site all-year-round simulation result.
Table 3.
Full-site all-year-round simulation result.
Time | Temperature (Existing Trees) | Temperature (New Trees) | Thermal Stress Level | Reduced UTCI (°C) | Ranking |
---|
Hottest Day | 40.71 | 38.51 | Very Strong Heat Stress | 2.2 | null |
Coldest Day | 20.51 | 19.54 | No Thermal Stress | 0.97 | null |
Jan. | 24.81 | 23.23 | No Thermal Stress | 1.58 | 4th |
Feb. | 25.92 | 24.38 | No Thermal Stress | 1.54 | 5th |
Mar. | 28.36 | 27.17 | Moderate Heat Stress | 1.19 | 11th |
Apr. | 30.36 | 28.87 | Moderate Heat Stress | 1.49 | 7th |
May | 31.68 | 30.32 | Moderate Heat Stress | 1.36 | 9th |
Jun. | 34.86 | 33.55 | Strong Heat Stress | 1.31 | 10th |
Jul. | 35.38 | 33.87 | Strong Heat Stress | 1.51 | 6th |
Aug. | 36.8 | 34.81 | Strong Heat Stress | 1.99 | 1st |
Sep. | 36.66 | 34.7 | Strong Heat Stress | 1.96 | 2nd |
Oct. | 31.37 | 29.47 | Moderate Heat Stress | 1.9 | 3rd |
Nov. | 27.44 | 26.05 | Moderate Heat Stress | 1.39 | 8th |
Dec. | 25.64 | 24.55 | Moderate Heat Stress | 1.09 | 12th |