.....The last time the West experienced sustained arid conditions over decades was a 28-year dry spell that ended in the year 1603, researchers say.
“We now have a full, uninterrupted record of soil moisture across western North America that extends from 800 A.D. all the way up to the near present,” said Park Williams, a bioclimatologist at Lamont-Doherty Earth Observatory at Columbia University, who led the study. “That allows us to compare for the first time this drought event to the big megadroughts. And the development of this prolonged drought that began in 2000 looks indistinguishable from those big megadroughts.”
The study looked at California, eight other states and Northern Mexico.
A Worst-Case Scenarios for Water Managers
Scientists have long known that the West suffered in the distant past under anomalous dry periods that lasted for decades.
The region returning to what researchers call a megadrought or a “paleo-drought” is considered to be a worst-case scenario for water managers.
Researchers say the region experienced megadroughts in the 9th, 12th, 13th and16th centuries, disrupting Native American cultures. For example, dry conditions are believed to have driven the Anasazi from their pueblo settlements in Arizona, New Mexico, Colorado and Utah.