Posted on 03/02/2004 5:40:51 PM PST by AM2000
SURT, Libya — In one of the largest construction projects in the world, engineers are trying to "mine" ice age rainfall, now locked in the sandstone beneath the Sahara, and convey it to Libyan cities and farms along a vast waterworks.
The project is almost invisible, except when something goes wrong.
Bashir O. Saleh, a Libyan engineer trained at the University of Texas, has devoted his professional life to the project, the $27 billion Great Manmade River. In an interview, he described what had happened repeatedly on the first 500-mile segment of the pipeline system that taps a series of "fossil water" aquifers beneath the Libyan desert.
Mammoth sections of pipe buried six feet under the desert floor burst out of the sand dunes like submarines breaking the surface of the ocean. Each time it happens, Mr. Saleh said, "it is a catastrophe."
Two decades after the Libyan leader Col. Muammar el-Qaddafi mounted this multibillion-dollar public works project as "the eighth wonder of the world" that would "create a new society," nothing is settled about the best long-term solution for Libya's widespread water deficit.
But the option that Colonel Qaddafi chose — the extensive pipeline and pumping system that bores into the earth to draw down nonrenewable reserves of fossil water — is now about half completed on a landscape twice the size of Texas and has been delivering water for more than a decade, with occasional interruptions for repairs.
Construction is still under way on connecting branches, as it is here near Surt, where a great gash in the desert exposes freshly laid pipeline that looks big enough to support a subway train.
The first pipeline blowout occurred in August 1999, and disaster struck repeatedly over the next several years, until engineers figured out how to reduce corrosion that was weakening the pipe and causing it to buckle under the water's enormous force.
Each failure started as a rumble, then an eruption, followed by a geyser shooting 100 feet into the air — a subterranean beast, as one of Mr. Saleh's assistant engineers put it, being flung out of the earth with the pressure of a dam burst.
"Some of these huge pieces of pipe were hurled 50 meters by the force of the water," he said. "It's a mess."
With each failure, repair crews were dispatched like counterattacking armies of bulldozers and 450-ton cranes. Their work — digging out the damaged sections and hoisting new ones — was hampered by the flooding. For weeks, they struggled to nestle, nudge and wedge new 75-ton pipe sections back into the ground to recreate the seamless conveyance before the manmade river could be turned on again at its source.
The source is the array of well fields that puncture the desert at places called Tazerbo and Sarir, sending pipes down nearly 1,500 feet (the height of the Empire State Building, with antenna) to the soft water-bearing rock — part of the Nubian sandstone aquifer system, which stretches into Egypt, Sudan and Chad and may be the world's largest such aquifer of fossil water.
The overall system was designed by subsidiaries of Halliburton and Price Brothers Company in the United States. The basic design work was completed before sanctions were imposed on Libya, in the mid-1980's. The companies have remained as consulting engineers through overseas subsidiaries.
Though many of Libya's airports, aircraft, hospitals, roads and schools have decayed and crumbled during Colonel Qaddafi's 35 years in power, the waterworks, like the oil sector, have commanded high priority. If Libya had not addressed the water crisis that became increasingly urgent after its 1969 revolution, the country would be scarcely habitable, experts say. The orange and olive groves would have died off from saltwater intrusion, and the 5.6 million Libyans, 85 percent of them on the Mediterranean coast, would have been forced to migrate, or return to a subsistence economy based on rainfall collection.
"Without it, really we would have no future," Mr. Saleh said. "We would have to leave the country."
Over the years, the vast Libyan waterworks has been derided as Colonel Qaddafi's "pipe dream." Western intelligence agencies have floated stories, since discredited, that the tunnels, roughly 13 feet in diameter, were conduits for military hardware, including tanks and illicit chemical weapons stockpiles.
The discovery of large reserves of fossil water near the surface in Libya came with the discovery of oil, when Occidental Petroleum and other American firms started punching holes in the desert in the late 1950's.
Much of it fell as rain 25,000 to 75,000 years ago, said Prof. Mike Edmunds, director of the Oxford University Center for Water Research. Professor Edmunds has also spent much of his career studying the geology of the Libyan desert and surveying its subterranean water resources. The rest fell 4,500 to 10,000 years ago, he said, when Libya was a broad and lush savanna, where elephants, giraffes, leopards and great herds roamed while early humans harvested crops on plains washed by heavy rains.
Rainfall collected in huge formations of sandstone, where the soft rock acted like a sponge and impervious rock below it slowed or prevented migration out of the region.
"This is a legacy from the past, and one has to use it with great care if you want to safeguard it for future generations," Professor Edmunds said. Fossil water must be used responsibly, he added, "so that nobody can look back and say, `What a waste!' "
The same might be said of Libya's oil wealth, which has largely been squandered on Soviet-era weapons and once secret programs to produce chemical and nuclear weapons. Colonel Qaddafi abandoned these programs in December.
If fossil water were oil, Libya would be Saudi Arabia. Though finite, its fossil water resources are almost unimaginable in scale: the equivalent of a lake larger than Germany and hundreds of yards deep.
The Kufra Basin in southeast Libya has an estimated groundwater storage capacity of nearly 5,000 cubic miles just in the Libyan sector.
Mr. Saleh says that even if Libya pumps fossil water for 100 years, there will still be ample reserves for future generations. Professor Edmunds agrees, but emphasizes the need for conservation.
"In the case of Libya, a large country with a small population and vast reserves of fresh water beneath the desert, the scale of depletion compared with the scale of the resource is still relatively small," he said.
Still, few experts are certain that in another 30 years it will make sense to draw heavily on water reserves in the face of declining costs for desalting and the scaling back of ambitious plans to use fossil water to support wheat farming in the desert, a folly that Saudi Arabia tried and will have to abandon as its water reserves are exhausted over the next two decades.
For now, 11 years after the first water started flowing, Libya is committed to mining its water resources, whose volume, when all the pipelines are completed, will be about 200 million cubic feet of water per day, roughly the flow of the Thames River in England, Mr. Saleh says.
In a world so desperately short of water in so many drought-prone regions, Libya's water bounty is a national treasure that seems destined to be spent. But all the questions, the experts agree, relate to how fast and with what plan for frugality.
This may be for subscribers to Science News only, but it has a terrific photo that vividly illustrates ground subsidence.
Withdrawal of groundwater in California's San Joaquin valley has caused the ground to subside by more than 9 m. Signs in this 1977 photo, taken near Mendota, show where the ground surface was in 1925 and 1955.
U.S. Geological Survey
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The ability of a sophisticated radar instrument to image large regions of the world from space, using different frequencies that can penetrate dry sand cover, produced the discovery in this image: a previously unknown branch of an ancient river, buried under thousands of years of windblown sand in a region of the Sahara Desert in North Africa. This area is near the Kufra Oasis in southeast Libya, centered at 23.3 degrees north latitude, 22.9 degrees east longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR- C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on its 60th orbit on October 4, 1994. This SIR-C image reveals a system of old, now inactive stream valleys, called "paleodrainage systems."
I'll bet once you process the water it is just like any other water. It seems that Col. Muammar el-Qaddafi did at least one thing of value to his people.
Water vapor is a much more powerful greenhouse gas than CO2. Where's the outcry?
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