for National Geographic News
Sudan's dusty Darfur region was once home to a giant lake, scientists say, and underground water could remain that would aid refugees in the war-torn region.
Satellite data of the eastern Sahara revealed the contours of an ancient basin the size of the U.S.'s Lake Erie.
"This may be the driest place on Earth today, but only 5,000 years ago it had a much kinder climate with rivers, lakes, vegetation, animals, and man," said Farouk El-Baz, director of the Center for Remote Sensing at Boston University in Massachusetts.
While the lake has since dried up, much of its water likely seeped into the porous rock underneath to become part of the groundwater there today.
El-Baz said that mapping the former lake may help with groundwater exploration efforts in the troubled Darfur region, where access to freshwater is scarce.
A new water source could help the reported 2.5 million people driven from their homes since fighting began between ethnically African rebels and the Arab-dominated central government in 2003.
(Watch a video series about the Darfur crisis as seen through the eyes of survivors and journalists.)
Wet and Dry
In the early 1980s El-Baz detected a similar lake in neighboring southwestern Egypt (Sudan map).
In that basin, called East Uweinat, groundwater was found at about 80 feet (25 meters) below the surface.
The discovery resulted in the drilling of some 500 wells to irrigate up to 150,000 acres (60,700 hectares) of agricultural land.
"It's now a very lush, green area," El-Baz said.
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