Development puts the heat on cities
06/03/2007 The Star By V.P. SUJATA

PUTRAJAYA: Kuala Lumpur, Penang, Johor Baru and the administrative capital of the nation, Putrajaya, are 5 °C hotter than other cities in the country.

Rapid development and the lack of trees are turning these cities into urban heat islands (UHI) that are hot even at night.

Scientifically, Kuala Lumpur and the other cities are termed as UHIs, a phenomenon where concrete surfaces trap heat during the day and release it during the night.

The temperature at the UHI can reach up to 40 °C, a contributing factor to global warming that brings about heavy rain and flash floods.

The average temperature in the morning is between 24 °C and 27 °C while in the afternoon, it increases from 33 °C to 40 °C and starts dropping slowly at night. Kuala Lumpur’s night heat can even be at 30 °C.

Drainage and Irrigation Department deputy director-general (I) Ahmad Fuad Embi said yesterday that most cities are heavily built up with concrete buildings, and grounds covered with tar and tiles that absorb and release heat.

Low-maintenance plants like palms, instead of trees that provide more shade, do not help to cool temperatures.

“Ipoh has large shady trees like the Flame of the Forest planted during the colonial days which help keep the heat away,” he said.

Dark-coloured roof tiles heat up the air while light coloured ones reflect heat away.

Ahmad Fuad said cities must reduce damage to the environment by following the guidelines provided by the International Council for Local Environmental Initiatives.

The six “cooling” policies are to use cool community strategies in public buildings; amend building codes to include reflective roofing standards; amend landscape and development standards to include shade coverage requirements; include cool community guidelines in master plans and in agreements with developers; create incentives for cool action; and sponsor demonstration projects and contests.

“This international initiative has already taken place with cities having programmes to cool down their towns, including Singapore.

“Malaysia should follow suit and use the same guidelines quickly to repair the damage done,” he said.

Among the preventive measures that Malaysia could take would be planting more shady trees and grass at car parks and changing roof tiles to high albedo (reflectivity) ones.

“Roof tile makers still do not want to take this into consideration; for them, colour plays an aesthetic role,” he said, adding that buildings should preferably be white.

He also encouraged a roof garden programme where greens are planted on flat roofs to absorb heat.

Places like Putrajaya, where many areas are paved with marble, granite or ceramic, he said, need to be protected from the sun with large shady trees.