Paved surfaces bad for polluted cities

William Atkins
Wednesday, 08 June 2011 22:29

Science - Climate

Research headed by the U.S. National Center for Atmospheric Research has found that paved roads in coastal cities, like Houston, Texas, create less breezes, which makes it more difficult for pollution to blow out to sea and away from such areas. The result: more pollution.

As more paved roads, parking lots, and driveways are built in coastal cities, especially those fast growing ones in warmer climates, this research shows that pollutant will likely be an increasing problem.

The National Science Foundation article 'Air Quality Worsened by Paved Surfaces' on June 7, 2011, states, 'New research focusing on the Houston area suggests that widespread urban development alters weather patterns in a way that can make it easier for pollutants to accumulate during warm summer weather instead of being blown out to sea.'

Further, 'The reason: the proliferation of strip malls, subdivisions and other paved areas may interfere with breezes needed to clear away smog and other pollution.'

The international study, which was headed by NCAR scientist Fei Chen, found that pavement soaks up more heat in the summer months (than does natural surfaces) and keeps such areas warmer than normal throughout the night.

Thus, the temperature on land is not as cool as it would normally be - in fact, it is closer to the temperature over the water.

Consequently, with less differences in temperatures, fewer breezes are created, which hinders the ability of such winds to blow pollutants out to sea.

The NSF article adds, 'In addition, built structures interfere with local winds and contribute to relatively stagnant afternoon conditions.'

Page two continues.