How a desert detective found water in Darfur – from half a world away
Farouk el-Baz has been peering into the deserts of the world for 21 years – from hundreds of miles up and 10,000 miles away. The Egyptian-born geologist and his staff pore over satellite imagery at Boston University's Center for Remote Sensing, seeking clues to deserts' most precious resource: water. The water reserves he announced in April may increase an even more precious resource: peace in Darfur.
"Providing a source of clean water in this region would remove one of the main sources of conflict," Mr. Baz says, sitting in an office lined with bookshelves, awards, photos of him with various world leaders, and a giant image of the Arabian desert.
So important is the potential Massachusetts-size underground aquifer, the remains of a lake that dried up 5,000 to 11,000 years ago, that when the news broke, Baz got a call to speak to the head of the United Nations, Ban Ki Moon.
"I briefed the secretary-general personally," Baz says. "He doesn't have 10 minutes for some heads of state, but I gave him a 10-minute presentation, and then he asked questions for 40 minutes. He loved it."
A United Nations Environmental Program report released this past June said "serious water shortages" in Darfur, combined with population growth and environmental degradation, "created the conditions for conflicts to be triggered and sustained" between Arab militias and farmers in the region. Some 3.5 million people in Darfur are living without reasonable access to water, says Craig Miller, president of Thirst No More, a humanitarian group based in Texas that is working on water projects in Darfur and Peru.
Now the UN, Egypt, and even the Sudanese government – which has been accused of complicity in the attacks – have signed on to finance the Baz-initiated "1,000 wells for Darfur" project. First, the UN will dig 24 wells to test Baz's premise once safety conditions on the ground permit, most likely next year. If those wells are successful, they will supply water for the 26,000 UN troops headed for Sudan.
Baz has done this before; he found an ancient lake in Egypt in the early 1980s.
A find in Egypt yielded 500 wells
It took him 15 years, though, to persuade his homeland to dig the first well and another few years to convince them that the water was plentiful there. Today Egypt has 500 wells yielding enough water to last an estimated 100 years and support 150,000 acres of agriculture in the area around an ancient lake.
As the conflict in Darfur escalated, Baz and his team at BU turned their attention to the paleohydrology (ancient water) of the region, to see if a similar water source was available.
A year and a half ago, one of his research assistants, Eman Ghoreim, was poring over satellite radar images of Sudan when she noticed some narrow, dark lines set close together. Fractures in the bedrock? Something else? Baz took a look.
From his field research in the Sahara and his past discoveries, Baz knew the lines might indicate gravel deposits. Sand is easily penetrated by satellite radar; the bedrock beneath it shows up as off-white in the images. But gravel and similar sediments cannot be penetrated by radar, and they appear darker on the image. Baz suspected that it was gravel deposited by an ancient water source during the last wet age in the region, some 5,000 to 11,000 years ago. The lines might indicate the banks of an ancient lake, with multiple lines indicating the shore shrinking as the climate dried out.
To confirm their finding, Ms. Ghoreim and Baz examined other types of radar and topographical imagery. An image using radar data from the space shuttle showed darker grooves beneath the sand that led up to what they thought was shoreline. Were they ancient dry rivers that had fed the lake?
"Some people said, 'Oh, those lines are just fractures,' " Ghoreim says. "But when we found that they all stopped exactly along the 'shoreline,' we knew that probably wasn't true."
Topographic images then showed the elevations in the surrounding area. The land in and around the suspected ancient lake was flat and low, typical of a lakebed, and it rose like the lip of a plate near the dark lines that indicated a shoreline.
Looking more closely, the BU team found other bits and pieces of shoreline.
They put the data into a powerful computer loaded with special geology software. The program ran for three days, processing satellite images and researchers' findings, before it spat out an image of what the lake might have looked like, given the location and size of the tributaries, the shoreline fragments, and other geographic considerations. The resulting image showed a deep lake about the size of Massachusetts.
Ancient water seeps into sandstone?
The fact that sandstone lies beneath the ancient lake means that much of the lake's water should have seeped into it to accumulate as groundwater.
Most of the satellite imagery used to find the ancient lake was from free public sources. Others were rather pricey, at $3,000 apiece. But the fact is that others looking at the images could easily have missed what Baz saw, Ghoreim says.
"He is very patient and has trained eyes to look for certain things that others wouldn't notice," she says. "It's not just about looking at an image; you need to be able to find the right interpretation."
Born in Zagazig, Egypt, in 1938, Baz earned degrees from Ain Shams University in Cairo, the University of Missouri at Rolla, and the Massachusetts Institute of Technology in Cambridge, Mass. After working as an instructor and oil geologist in Egypt, he came to the United States in 1967 to work on the Lunar Science Planning and Operations at Bell Telephone Laboratories in Washington, D.C. Among his assignments: training NASA astronauts what to observe and photograph about lunar and earth geology. He left in 1973 to become research director of the Center for Earth and Planetary Studies at the National Air and Space Museum. That's when he began his research on deserts, particularly looking at how space data can help explain the origin and evolution of deserts on Earth. After a brief stint at a high-tech firm, he joined BU in 1986.
His desire to become a desert expert was spawned, ironically, from his lack of knowledge about this environment.
"I came from Egypt, which is 95 percent desert; I had studied them in the best universities and rubbed shoulders with some of the best geologists, but I realized, like the rest of the geology profession, what I really knew about deserts was close to zero," he says.
Even though Baz says the imagery of the Darfur site looks identical to the ancient lake site he found in Egypt, he still has a few critics.
"There are doubters that say, 'All I see is salt and sand,' " he says. But he's learned from his experience in Egypt not to worry: "I'm used to these doubters."
He plans to go to Darfur next month to confirm the lake's existence and select sites for the first wells. It will be years before all 1,000 wells are dug, and a pipeline is needed to transport water from the wells to where most people live, 250 miles away.
