Columbia River Basin Survey Reveals Huge Historic Drought Cycles

[hatrack]

Historical droughts in the Columbia River Basin were more severe than anything in recent memory, including the drought of 1992-93, scientists said Monday. A study of tree rings found four droughts between 1750 and 1950 that were "much more severe than anything in recent memory" because they persisted for years.

One drought that started in the 1840s lasted 12 years. Flows on the Columbia River were at least 20 percent below long-term averages and might have been much lower, said lead author Ze'ev Gedalof of the University of Guelph in Ontario. Reliable river flow records go back only about 75 years. But tree-ring data reveals how much trees grow each year, a reflection of climate.

"Imagine what a drought lasting that long would do to the resources and economy of the region today," says Dave Peterson of the U.S. Forest Service and the University of Washington's College of Forest Resources. Five other multiyear droughts were identified, around 1775, 1805, 1890, 1925, and one in the 1930s coinciding with the Dust Bowl era.

EDIT

That work, also based on tree-ring data and published in October, revealed that an ongoing drought in much of the Southwest has not achieved the level of aridness (ed. - sic) revealed in history. The current drought "pales in comparison with some of the earlier droughts we see from the tree-ring record," said David Meko, a University of Arizona researcher. "What would really put a stress on society is decade-long drought."

EDIT

http://www.msnbc.msn.com/id/6970736/

[mike_c]

1. ahh, the delusions of western water bureaucrats....

One thing you can count on is that the real droughts will come around again.

[Warpy]

2. The drought may be over in New Mexico

but the one thing it accomplished was getting rid of most of the lawns in this city. People shut off their sprinklers and xeriscaped.

My own lawn kicked the bucket about 5 years ago. I have no idea what the ground cover I have now is, but it's a lovely green with little yellow flowers.

[stevedeshazer]

3. The West was settled (by whites) during mostly wetter times

More drought is inevitable.

Almost all Western US cities are on a path toward unsustainable growth given the water supplies.

[kineneb]

4. the west is desert or semi-desert

and anyone who thinks otherwise is deluded. "Cadillac Desert" should be required reading in all high schools west of the Rockies. Reisner really laid out the history of water in the west and a sordid tale it is. And of course, drought is more a part of the environment than many know or care to admit.

Before it was settled by people, the great valley of California was really a big savanah, with seasonal grasses and grazing animals, much like parts of Africa. My how we have changed it. But in late summer one can occasionally glimpse how it would have looked long ago.