BOB HIRSHON (host):
Big troubles ahead for rivers. I’m Bob Hirshon and this is Science Update.
In the next fifty years, climate change could cause many of the world’s rivers to either swell or deplete. And man-made dams will heighten this effect, disrupting the lives of up to a billion people. This according to a study led by University of Maryland ecologist Margaret Palmer. She says rivers normally adjust to changes in flow by shifting their paths, or by storing excess water in flood plains and releasing it later.
MARGARET PALMER (University of Maryland):
When you put a dam in a major river basin, what you’ve actually done is you’ve removed a lot of those elements that allow rivers to absorb disturbances like droughts and floods, and moderate the impacts.
Her report recommends taking preventive action now, like restoring flood plains or engineering water storage systems, in order to avoid more costly emergencies in the future. I’m Bob Hirshon, for AAAS, the science society.