Human activities can affect rainfall

June 20, 2006

U.S. researchers say they've determined human activities in arid urban environments can affect the rainfall and water cycle.

While scientists have known for some time the so-called "heat-island" effect of large cities can affect weather, they knew less about that effect and other processes in arid cities, such as Phoenix, that have experienced explosive population growth.

Now, a study by Marshall Shepherd, a climatologist at the University of Georgia, has shown -- using a unique 108-year-old data record and NASA's Tropical Rainfall Measuring Mission satellite -- arid cities such as Riyadh in Saudi Arabia and Phoenix have an effect on rainfall patterns around them.

The study showed a 2-percent increase in rainfall in Phoenix, but researchers said that could be an anomaly.

As important, it appears human activities such as land use, aerosols and irrigation in these arid urban environments affect the entire water cycle as well.

"Many of the fastest-growing urban areas are in arid regimes," said Shepherd. "Because their total rainfall is low, these areas have been largely ignored in studies on how human activities affect the water cycle. But these cities are particularly sensitive to such changes, since the water supply is so critical."

The research appears in the online edition of the Journal of Arid Environments.

Copyright 2006 by United Press International

Explore further: Warming climate is deepening California drought

Related Stories

Warming climate is deepening California drought

August 20, 2015

A new study says that global warming has measurably worsened the ongoing California drought. While scientists largely agree that natural weather variations have caused a lack of rain, an emerging consensus says that rising ...

China's struggle for water security

April 18, 2015

Way back in 1999, before he became China's prime minister, Wen Jiabao warned that water scarcity posed one of the greatest threats to the "survival of the nation".

Recommended for you

New study sheds light on end of Snowball Earth period

August 24, 2015

The second ice age during the Cryogenian period was not followed by the sudden and chaotic melting-back of the ice as previously thought, but ended with regular advances and retreats of the ice, according to research published ...

Earth's mineralogy unique in the cosmos

August 26, 2015

New research from a team led by Carnegie's Robert Hazen predicts that Earth has more than 1,500 undiscovered minerals and that the exact mineral diversity of our planet is unique and could not be duplicated anywhere in the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.