Quantifying thermal comfort improvement by palm tree-based street greening, in hot and dry climate

Naama KHELIFA; Moufida BOUKHABLA; Soumia BOUZAHER

doi:10.22630/srees.10366

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Quantifying thermal comfort improvement by palm tree-based street greening, in hot and dry climate

Scientific Review Engineering and Environmental Sciences

Volume 35 (2026): Issue 2 (June 2026)

By: Naama KHELIFA , Moufida BOUKHABLA and Soumia BOUZAHER

Open Access

|Jul 2026

Figures & Tables

Study area: S1 – site of the traditional individual residential fabric, S2 – site of the collective housing fabricSource: own work.

Location of the studied streets in Sidi Okba: a – macroscale of the country, b – microscale of Biskra ProvinceSource: own work.

A multifunctional portable device Testo 480-AG 501 1ST, 0563 4800Source: own work.

Model domain for the study in ENVI-met in current situation for Street Str1: a – 2D, b – 3D Source: ENVI-met.

Model domain for the study in ENVI-met: a – current situation, b – proposed for Street Str2 Source: ENVI-met.

Validation of the simulation models on Street 1 (St1, St2) and Street 2 (St3, St4) Source: own work.

Visualization outputs generated by Leonardo’s (Street 1) modeling software for the current situationSource: Leonardo from the ENVI-met simulation program.

Visualization outputs generated by Leonardo’s (Street 2) modeling software for the current simulation scenarioSource: Leonardo from the ENVI-met simulation program.

Visualization outputs generated by Leonardo’s (Street 2) for the proposed simulation scenario Source: Leonardo from the ENVI-met simulation program.

Comparison of the daily average air temperature in Streets Str1 and Str2: current versus proposed scenariosSource: own work.

Comparison of the daily average relative humidity in Str1 and Str2: current versus proposed scenariosSource: own work.

Comparison of the daily average wind speed in Streets Str1 and Str2: current versus proposed scenariosSource: own work.

Comparison of the daily average mean radiant temperature (MRT) in Streets Str1 and Str2: current versus proposed scenariosSource: own work.

Comparison of the daily average physiological equivalent temperature (PET) in Streets Str1 and Str2: current versus proposed scenariosSource: own work.

Comparison of the daily average new standard effective temperature in Streets Str1 and Str2: current versus proposed scenariosSource: own work.

Simulation’s settings

Situation (geographic coordinates)	latitude: 34°75′, longitude: 5°57′
Simulation date	July 10–12, 2024
Simulation start time	06:00:00 a.m.
Initial temperature	31°C
Simulation duration	48 hours
Relative humidity at 2 m above ground [%]	20%
Wind speed at 10 m	2 m⸱s⁻¹
Wind direction	135°
Specific humidity in 2,500 m	8.00 g·kg⁻¹

Comparison of the daily average air temperature for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	31.26	33.75	37.38	40.19	42.70	41.44	40.16	38.16	36.18	34.29	32.42	30.53
St2	31.75	34.68	37.93	41.28	44.37	43.59	41.56	39.66	37.36	35.52	32.84	31.05
St3	34.75	38.79	42.56	46.78	47.82	46.82	44.17	41.67	39.07	36.86	34.77	32.39
st4	35.18	39.36	43.95	48.47	49.57	47.85	45.19	42.33	39.88	37.59	35.18	32.96
St3′	32.86	37.01	40.16	43.59	45.59	44.07	42.55	40.00	37.91	35.85	33.78	31.62
St4′	33.88	37.95	41.90	46.05	47.13	45.79	42.95	40.71	38.52	36.54	34.18	31.85

Comparison of the daily average physiological equivalent temperature for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	28.00	45.70	55.80	58.30	60.70	57.70	47.00	32.80	31.10	29.50	27.80	26.20
St2	28.40	46.20	55.90	59.00	62.00	59.30	47.90	34.10	32.10	30.50	28.10	26.60
St3	30.30	48.70	58.90	62.90	63.70	60.50	48.80	35.60	32.90	31.00	29.20	27.10
St4	30.60	49.10	59.90	64.20	64.90	61.00	50.80	39.00	35.90	33.20	30.00	27.60
St3′	29.00	47.20	56.90	60.30	62.10	58.60	47.70	34.90	32.20	30.50	28.80	26.80
St4′	30.40	47.00	56.40	61.30	63.10	60.70	49.40	35.50	33.40	31.60	29.50	26.70

Sites and measurement stations

Site	Street	Street trees
Site	Street	number / type
S1 Traditional individual residential fabric
Section on the street (Str1)Measurement point (St1, St2)
S2 Collective housing fabriMeasurement point (St3, St4)		2 palm tree (Phoenix dactylifera)1 berry tree1 Ficus retusa
Section on the street (Str2)

Temperature for current situation scenario

Street	Station	Type	Min temperature [°C]	Max temperature [°C]
Str1	St1	field measurement	30.53	42.70
Str1	St2		31.05	44.37
Str2	St3		32.39	47.82
	St4		32.96	49.57
	St3′	simulation (greening)	31.62	45.59
	St4′	simulation (greening)	31.85	47.13

Comparison of the daily average relative humidity for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	44.16	43.34	38.17	32.84	29.71	27.97	30.12	33.50	35.72	37.74	39.70	41.66
St2	42.30	41.95	36.26	30.94	28.08	26.77	28.62	32.21	34.23	36.04	37.79	39.54
St3	25.04	23.95	19.89	15.99	12.65	11.09	13.22	16.59	18.88	21.07	23.25	25.44
St4	23.18	22.82	18.06	14.91	11.05	10.06	12.11	15.19	17.18	20.07	22.05	24.23
St3′	32.88	30.07	26.05	21.93	19.23	18.08	20.06	23.25	25.27	27.73	30.18	31.98
St4′	29.87	27.39	23.16	19.55	17.28	15.90	18.34	21.54	23.75	25.88	28.00	30.13

Comparison of the daily average mean radiant temperature for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	27.01	36.28	46.07	53.48	54.61	50.56	44.12	32.15	31.13	29.09	26.91	25.20
St2	29.04	40.14	49.57	56.68	57.62	54.01	47.30	36.11	34.12	32.16	30.86	28.70
St3	36.11	53.85	67.03	75.05	75.62	67.49	57.18	46.42	43.23	40.49	39.07	38.26
St4	39.85	57.36	70.33	77.99	79.71	71.61	60.40	50.94	46.93	44.49	43.15	41.25
St3′	32.36	43.46	53.50	64.83	66.98	60.16	49.56	39.41	36.02	34.03	32.17	30.17
St4′	34.00	46.19	57.05	68.16	71.55	63.15	52.68	42.67	38.84	35.92	33.85	32.24

Summary of the validation of simulated models for Street 1 (St1, St2) and Street 2 (St3, St4)

Station	Regression equation	R²	RMSE [°C]	MAE [°C]	RMSPE [%]
St1	y = 1.0164x + 0.3457	0.8926	1.60	1.19	4.33
St2	y = 1.2529x – 7.8296	0.8931	2.15	1.74	5.79
St3	y = 1.0676x – 2.5545	0.9980	1.50	1.21	4.09
St4	y = 0.9474x + 1.9583	0.9990	1.42	1.14	3.87

Comparison of the daily average new standard effective temperature for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	25.50	43.60	51.50	54.10	56.60	53.60	44.80	31.70	29.60	27.50	25.40	23.20
St2	26.00	44.00	51.60	54.80	57.90	55.30	45.60	33.20	30.80	28.80	25.70	23.70
St3	28.2	45.8	54.8	58.9	59.7	56.6	46.2	33.7	31.2	29	26.9	24.30
St4	28.5	46.1	55.8	60.3	61.00	57.1	46.6	34.1	31.9	29.7	27.2	25.00
St3′	26.7	44.7	52.7	56.2	58.1	54.6	45.3	33.6	30.6	28.5	26.4	23.9
St4′	25.7	42.2	49.7	54.1	55.6	53.3	44.8	34	31.1	28.3	25.2	21.9

Comparison of the daily average wind speed for Streets Str1 and Str2

Station	Hour
Station	6:00	8:00	10:00	12:00	14:00	16:00	18:00	20:00	22:00	0:00	2:00	4:00
St1	0.18	0.19	0.19	0.17	0.17	0.15	0.14	0.14	0.15	0.15	0.15	0.16
St2	0.48	0.49	0.47	0.47	0.45	0.44	0.44	0.44	0.44	0.45	0.45	0.45
St3	0.84	0.86	0.86	0.84	0.82	0.80	0.79	0.79	0.79	0.79	0.79	0.79
St4	1.02	1.01	1.02	1.01	1.01	1.01	1.01	1.01	1.01	1.01	1.01	1.01
St3′	1.10	1.12	1.11	1.09	1.08	1.07	1.07	1.07	1.07	1.07	1.07	1.06
St4′	1.29	1.29	1.30	1.29	1.29	1.29	1.29	1.30	1.30	1.30	1.30	1.30

References

Authors

Metrics

Articles in this issue

DOI: https://doi.org/10.22630/srees.10366 | Journal eISSN: 2543-7496 | Journal ISSN: 1732-9353

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Language: English

Page range: 158 - 183

Submitted on: Mar 15, 2026

Accepted on: Apr 23, 2026

Published on: Jul 7, 2026

Published by: Warsaw University of Life Sciences - SGGW Press

In partnership with: Paradigm Publishing Services

Keywords:

outdoor thermal comfort,

OTC,

Related subjects:

Architecture and design,

Architecture,

Architects, buildings,

Geosciences,

Geosciences, other,

Engineering,

Mechanical engineering,

Fundamentals of mechanical engineering,

Geosciences,

Geology and mineralogy

© 2026 Naama KHELIFA, Moufida BOUKHABLA, Soumia BOUZAHER, published by Warsaw University of Life Sciences - SGGW Press
This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 License.

Volume 35 (2026): Issue 2 (June 2026)

Quantifying thermal comfort improvement by palm tree-based street greening, in hot and dry climate

Figures & Tables

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FIGURE 15.

Simulation’s settings

Comparison of the daily average air temperature for Streets Str1 and Str2

Comparison of the daily average physiological equivalent temperature for Streets Str1 and Str2

Sites and measurement stations

Temperature for current situation scenario

Comparison of the daily average relative humidity for Streets Str1 and Str2

Comparison of the daily average mean radiant temperature for Streets Str1 and Str2

Summary of the validation of simulated models for Street 1 (St1, St2) and Street 2 (St3, St4)

Comparison of the daily average new standard effective temperature for Streets Str1 and Str2

Comparison of the daily average wind speed for Streets Str1 and Str2

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