There may be a hidden cost to urban expansion: more flooding.
There may be a hidden cost to urban expansion: more flooding.
A new Johns Hopkins study has found that for every percentage point increase of roads, parking lots, and other impervious surfaces, annual floods increase on average by 3.3%. This means that if an undeveloped river basin increases the amount of impervious surfaces from zero to 10%, scientists would expect, on average, a 33% increase in annual flooding.
The study was published today in Geophysical Research Letters.
"With recent major floods in heavily urbanized cities like Houston and Ellicott City, Maryland, we wanted to better understand how much urbanization is increasing flood flows," says Annalise Blum, a former postdoctoral fellow in Johns Hopkins University's Department of Earth and Planetary Sciences and the paper's first author. Blum, who received a Howard L. Pim Postdoctoral Fellowship in Global Change while at Johns Hopkins, is now a science and technology policy fellow at the American Association for the Advancement of Science.
Read more at Johns Hopkins University
Image: Urbanization can lead to more intense flooding, on average, researchers say. (Credit: David Goff)
