Dams can trigger more frequent fierce storms

Washington, Feb 5 (ANI): In a new study, scientists have suggested that dams, along with reservoirs, might trigger more frequent fierce storms.

According to a report in National Geographic News, the study was carried out by Faisal Hossain, an engineer at Tennessee Technological University in Cookeville, and Roger Pielke, Sr., a senior researcher at the University of Colorado at Boulder.

"The focus is not so much on average rainfall per se, but rather on the question of whether 25-year storm data that an engineer used to size a reservoir has now become a 15-year storm ... as the dams aged," said Hossain.

"It is the heavy rainfall that has tremendous implications on dam safety," he added.

Roger Pielke, Sr. pointed out that reservoirs behind large dams combine with land use changes accompanying dams to induce rainfall changes.

The long-term studies by Hossain and his colleagues suggest that dams have particularly altered extreme precipitation patterns in arid or semiarid areas.

"The Southwest U.S., Botswana, South Africa, southern Spain and central India showed up on our radar as having experienced a trend in the extreme precipitation in the period after the dam was built," he said.

Hossain and his colleagues have detected up to 4 percent higher precipitation per year where dams have been built.

Hossain and his team said their findings bear on an aging waterworks infrastructure particularly in the United States, where 85 percent of dams will be at least 50 years of age by the year 2020.

"We are hearing stories here and there that certain dams nowadays are having more flooding problems, and having to keep the spillways and sluice gates open more than usual," Hossain said, pointing to Folsom Dam, on California's American River.

"It remains to be seen if the dam itself either triggered or accelerated the flooding hazards," he added.

According to Brian Becker, chief of the Bureau of Reclamation's Dam Safety Office in Denver. "The idea that the reservoir could significantly impact the hydrology raises an interesting notion." (ANI)