Энэхүү ус дамжуулах систем нь Ливи, Египет, Чад, Судан улсын нутаг дэвсгэрийг хамарсан Нубийн элсэн чулуулаг усны ай сав системээс тэжээгддэг. Усны ихэнх хэсэг нь идэвхтэй усны эргэлтээс тусгаарлагдсан, шахаж гаргах тусам нөхөн төлжих боломжгүй чулуужсан нөөц ажээ.
Ливи улс 1983 онд тус төслийг санаачилж, 1984 оны наймдугаар сарын 28-нд Сарир хотод суурийг нь тавьсан байна. Улмаар 1991 онд уг сүлжээ ашиглалтад орж, өмнө нь далайн ус шүүвэрлэх үйлдвэр болон борхон борооны усанд найдаж байсан хойд зүгийн хотууд болон газар тариалангийн бүс нутгийг ундны болон тариалангийн усаар хангаж эхэлжээ.
1950-иад оны үед Ливид газрын тос хайх явцад цөлийн элсэн доорх асар том усны нөөцийг анх илрүүлсэн байна. Радиокаربون буюу нүүрстөрөгчийн он цаг тогтоох аргаар шинжлэхэд газрын доорх усны зарим хэсэг нь сүүлийн мөстлөгийн үеэс ч өмнө буюу одоогоос 40,000 орчим жилийн өмнөөс эхлэн Ливийн хөрсөн доор хуримтлагдсан болохыг тогтоожээ.
Олон улсын атомын энергийн агентлагийн мэдээлснээр Нубийн элсэн чулуулаг усны ай сав нь Нийл мөрний 500 жилийн урсгалтай тэнцэхүйц асар их нөөцтэй аж. Гэсэн хэдий ч эдгээр чулуужсан нөөц нь эргэн төлжих боломжгүй тул газрын тосны нэгэн адил ганцхан удаа л ашиглагдах бөгөөд цаг хугацааны явцад шавхагдах аюултай юм.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Libya’s Great Man-Made River carries water from ancient aquifers beneath the Sahara to cities and farming areas in the country’s north. Its underground network uses prestressed concrete pipes measuring up to four metres in diameter and can transport about 2 million cubic metres of water a day.
The system draws from the Nubian Sandstone Aquifer System, which stretches beneath Libya, Egypt, Chad and Sudan. Much of the water is a fossil reserve, isolated from the active water cycle and unable to replenish as it is pumped to the surface.
Construction Begins in the Libyan Desert in 1984
Libya established the project in 1983 as coastal areas faced severe water shortages and lacked sufficient renewable supplies for homes, agriculture and industry. The foundation stone was laid at Sarir on August 28, 1984.
Two years later, the Brega plant opened to produce the prestressed concrete pipes required for the network. The Great Man-Made River began supplying irrigation and drinking water to northern cities and agricultural areas in 1991. Those communities had previously relied on desalination plants and declining rain-fed aquifers near the coast.
The network pumps groundwater from reserves deep in the Nubian Sahara. An aquifer is a layer of permeable rock, sand or sediment that holds water underground. Water can remain there for thousands or even millions of years, and its passage through soil and rock can remove impurities.
Some of Libya’s Groundwater Is 40,000 Years Old
Oil exploration in Libya uncovered large underground water reserves during the 1950s. The country compared the cost of pumping that water with importing water from Europe or desalinating seawater, then selected the aquifers as the least expensive option.
Radiocarbon dating found that some of the groundwater had remained beneath Libya for about 40,000 years, since before the end of the last ice age. Geological changes had sealed the aquifer off from further recharge, turning the trapped supply into what scientists call fossil water.
A NASA Earth Observatory image captured on April 10, 2006, showed part of the Grand Omar Mukhtar water project near Suluq. The false-colour image recorded reservoirs and geometric areas of irrigated farmland, including circular fields associated with centre-pivot irrigation.
The Shared Aquifer Holds a Finite Reserve
The Nubian Sandstone Aquifer System is one of the world’s oldest and largest aquifers. The International Atomic Energy Agency put its reserves at the equivalent of about 500 years of Nile River discharge, or roughly 20 times the volume of the North American Great Lakes.
Its size does not make the supply renewable. The fossil reserves are not part of the surrounding hydrological cycle, so water removed from the aquifer cannot be replaced. The IAEA compared the reserve with oil: it can be used only once and could eventually run dry.
An IAEA-led project launched in 2006 used isotope hydrology to investigate the aquifer’s age, movement and response to human activity. Isotope hydrology examines naturally occurring forms of chemical elements in water to trace where the water came from and how it moves.
The project’s first phase produced a computer model capable of simulating groundwater movement and measuring how water levels may change over time.
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