INFOGRAPHIC: Taiwan’s Cities are One Giant Heat Sink

Taiwan’s cities can feel like a blast furnace in the summer, when the city absorbs heat and radiates it back into the air. This effect, called an urban heat island, can even be seen from satellites 800 kilometers up in the form of thermal infrared imagery.

This colorized image shows the greater Taipei region’s heat signature – brighter colors are giving off heat and darker reds and purples are absorbing it. Those splotches over downtown Taipei are clouds.

The concrete and steel that make up the city act as a giant heat sink, and by mid-afternoon -- when this image was captured -- urban Taiwan was radiating heat back onto its poor citizens.

The less-populated areas at Yangmingshan to the north of Taipei and the mountains to the south are full of trees and are at higher elevations, so they tend to be cooler and hold less heat. The farmland to the west of Zhongli and Pingzhen has many fish farms, which can be seen as small, cool polka dots along the edge.

Get permission from the locals before you go swimming in the fish pools to cool off.

Tainan shows this even more clearly; the flooded parcels to the northwest of the city are even cooler than the surrounding ocean. If you want to keep cool in Taiwan, start growing some rice or fish.

This last image shows that it isn’t just big cities that can create heat islands. In the small city of Taitung, the brightest spots are dry riverbeds around the city, which store much more heat than the surrounding vegetation.

These three images were all captured during different months of different years, so this doesn’t mean that Taitung is cooler than Taipei. There is almost never a sunny day over the entire island, so these images were chosen from days when individual cities peeked out from beneath the clouds.

Taipei as seen on April 11, 2017.

So what can we do about urban heat islands? Rooftops and insulation play an important part. Putting plants on roofs can help insulate and reflect heat (especially for all you rooftop dwellers), but painting roofs white can be effective while being much lower maintenance.

Many apartments in Taiwan are uninsulated, making them colder in the winter and hotter in the summer. Not only does this result in higher AC bills, it creates uninterrupted thermal masses that hold onto heat for longer. Taiwan would do well to sacrifice a few centimeters of space in apartments to put up some insulation, especially on the ceilings.

Editor: Edward White

Morley J Weston

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