Featured Research

from universities, journals, and other organizations

Floods And Droughts: Water Planners Call For Fundamental Shift To Deal With Changing Climate

Date:
February 5, 2008
Source:
University of Washington
Summary:
The past is no longer a reliable base on which to plan the future of water management. So says a new perspectives piece written by a prominent group of hydrologists and climatologists that calls for fundamental changes to the science behind water planning and policy.

Model-projected percentage change (2041-2060 vs. 1900-1970) in mean annual runoff volume for ice-free land, under the Intergovernmental Panel on Climate Change "SRES A1B" scenario. Blue areas are projected to gain water, while red areas will become significantly drier.
Credit: Science

The past is no longer a reliable base on which to plan the future of water management. So says a new perspectives piece written by a prominent group of hydrologists and climatologists, in the journal Science, that calls for fundamental changes to the science behind water planning and policy.

Related Articles


"With the climate changing, past years aren't necessarily representative of the future anymore," said co-author Dennis Lettenmaier, a professor of civil engineering at the University of Washington. "This paper says that the way business has been done in the past will no longer work in a changing climate."

Global spending on water infrastructure is currently more than $500 billion per year. Until now, managers at municipal water boards, the Army Corps of Engineers, the U.S. Bureau of Reclamation and other federal, state and local agencies have operated on the premise that historical patterns could be counted on to continue. The assumption was that variability from year to year occurred within stationary, unchanging patterns.

But human-induced changes to Earth's climate have begun to shift the averages and the extremes for rainfall, snowfall, evaporation and stream flows, the authors write. These are crucial factors when planning for floods or droughts, choosing the size of water reservoirs or deciding how much water to allocate for residential, industrial and agricultural uses.

"Historically, looking back at past observations has been a good way to estimate future conditions," said lead author Christopher Milly, a research hydrologist with the U.S. Geological Survey. "But climate change magnifies the possibility that the future will bring droughts or floods you never saw in your old measurements."

The old way of doing business is dead, the authors write. And it cannot be revived. Even with an aggressive reduction in greenhouse gas emissions, warming will persist and global water patterns will continue to show never-before-seen behavior.

The authors thus propose a planning framework like the Harvard Water Program, a project from the late 1950s to the early 1960s in which scientists and engineers hammered out the basis for the current water-management policies. The authors call for a renewed effort in the spirit of the earlier program that would incorporate shifting averages and variability.

Not all regions will experience the same changes in flows. Global warming augments atmospheric humidity and water transport. This increases precipitation, and possibly flood risk, where prevailing atmospheric water-vapor fluxes converge. Glacial meltwater temporarily enhances water availability, but glacier and snow-pack losses diminish natural storage of freshwater. In coastal regions the supplies are endangered by rising sea levels. The risk of contamination with seawater is heightened, the authors state.

From projections of future water availability a broad picture emerges of regional gainers and losers. "Our best current estimates are that water availability will increase substantially in northern Eurasia, Alaska, Canada and some tropical regions, and decrease substantially in southern Europe, the Middle East, southern Africa and southwestern North America," Milly said. Drying regions will likely also experience more frequent droughts, he said.

In the Western US, changes in precipitation and the timing of snowmelt now seem likely to affect seasonal flow patterns that are critical to salmon runs, water supply and other water uses, Lettenmaier said.

"For agencies like the Army Corps of Engineers and the Bureau of Reclamation, this would mean fundamental changes in the way they do business," he said. "If you look at plans by those agencies for management of the Columbia River, essentially they've ignored climate change. For instance, until quite recently, the National Marine Fisheries Service didn't even mention what climate change might mean for rehabilitation of fish runs."

Asked whether the new paper would prompt changes in management practices, Lettenmaier said: "I think so. I think it will become increasingly hard to ignore climate change in water management."

Journal article: Milly, P. C. D., Betancourt, J., Falkenmark, M., Hirsch, R. M., Kundzewicz, Z. W., Lettenmaier, D. P., Stouffer, R. J. (2008). Stationarity is Dead: Whither Water Management? Science 319, 573-574 (January 31, 2008)


Story Source:

The above story is based on materials provided by University of Washington. Note: Materials may be edited for content and length.


Cite This Page:

University of Washington. "Floods And Droughts: Water Planners Call For Fundamental Shift To Deal With Changing Climate." ScienceDaily. ScienceDaily, 5 February 2008. <www.sciencedaily.com/releases/2008/01/080131152015.htm>.
University of Washington. (2008, February 5). Floods And Droughts: Water Planners Call For Fundamental Shift To Deal With Changing Climate. ScienceDaily. Retrieved April 19, 2015 from www.sciencedaily.com/releases/2008/01/080131152015.htm
University of Washington. "Floods And Droughts: Water Planners Call For Fundamental Shift To Deal With Changing Climate." ScienceDaily. www.sciencedaily.com/releases/2008/01/080131152015.htm (accessed April 19, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Sunday, April 19, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nervous Return to Everest a Year After Deadly Avalanche

Nervous Return to Everest a Year After Deadly Avalanche

AFP (Apr. 18, 2015) In the Himalayan town of Lukla, excitement mingles with fear as mountaineers make their way up to Everest a year after an avalanche killed 16 guides and triggered an unprecedented shut-down of the world&apos;s highest peak. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
L.A. Water Cops Remind Residents of Water Conservation

L.A. Water Cops Remind Residents of Water Conservation

Reuters - US Online Video (Apr. 18, 2015) "Water cops" in Los Angeles remind the public about water conservation methods amid California&apos;s prolonged drought. Julie Noce reports. Video provided by Reuters
Powered by NewsLook.com
Planet Defence Conference Tackles Asteroid Threat

Planet Defence Conference Tackles Asteroid Threat

AFP (Apr. 17, 2015) Scientists gathered at a European Space Agency (ESA) facility outside Rome this week for the Planetary Defence Conference 2015 to discuss how to tackle the potential threat from asteroids hitting Earth. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
Gulf Scarred, Resilient 5 Years After BP Spill

Gulf Scarred, Resilient 5 Years After BP Spill

AP (Apr. 17, 2015) Five years after the Deepwater Horizon spill in the Gulf of Mexico, splotches of oil still dot the seafloor and wads of tarry petroleum-smelling material hide in pockets in the marshes of Barataria Bay. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins