The Washington, D.C.-based research organization conducted what it calls the Aqueduct project to evaluate, map and score the stresses on water supplies in 180 countries around the world – in both the 100 largest river basins by geographic area, and the 100 river basins with the highest populations.
The factors it evaluated included: the reliability of each river's renewable water supply, the seasonal variation in its water supply throughout the year, how often floods occur, and how often it experiences drought, as well as how had those droughts can be.
Eighteen rivers, the group found – from rivers like the Colorado and the Rio Grande in the U.S. to China's Yellow, Liao He and Daliao Rivers – are under what it calls "extremely high" water stress, meaning that more than 80 percent of their water for agricultural, domestic and industrial users is withdrawn each year.
When droughts occur, they place even more stress on already fragile resources in places like these – countries with a collective $27 trillion in annual economic output, WRI notes – especially when a river basin isn't managed effectively.
While well-established river management systems, like the decades-old one in place on the Colorado, help ensure "steady, predictable supplies," the report added this caution: "Even the most-established, iron-clad management systems start to crumble under increasing scarcity and stress."
See the entire article here: http://www.weather.com/news/science/environment/worlds-18-most-water-stressed-rivers-20140321
No comments:
Post a Comment