Mitigating the Urban Heat Island Effect in Megacity Tehran

Table 1

A review on maximum temperature in different cities, UHI mitigation methods, and their cooling effects as well as the percentage of energy saving of different UHI mitigation strategies in different regions. Planting shade threes shows the highest cooling effect (3 K) in Los Angeles.

Reference	Method	Maximum temperature	Reduction in temperature	Reported savings	City/region
[19]	Reroofing: lighter colors and planting shade trees	—	3 K	10%	Los Angeles
[25]	Replacing urban areas with grass land	30°C (surface temperature)	1.6 K	—	Hong Kong
[26]	New park nearby commercial area (1 km downwind)	40.3°C (surface temp. Of grass field)	1.5 K	15%	Tokyo
[27]	Reducing anthropogenic heat	—	1.2 K	4–40%	Tokyo
[28]	Large scale increase in surface albedo and vegetative fraction	37°C	0.5–1.5 K	10%; (at peaks)	USA
[29]	Building planting (walls and roofs)	28.95°C (1 m)	1.3 K	25%
[30]	Trees with broad canopies within residential yards	32°C	2.4 K	1.24 mio l Water/year	Phoenix
[30]	Roofs with high albedo and vegetation	28.2°C	—	24. 14. 45%	Barcelona, Palermon, Cairo
[31]	Low albedo, building geometrywind effects	34.4°C	0.7 K	—	Singapore