Libyen

Libya’s desert holds some of the Sahara’s best-known sand seas, vast dune landscapes such as Ubari and Murzuq in the southwest.

Far beneath them lies another kind of sand: compressed into sandstone, with ancient rainwater still held between the grains. When the Sahara was greener and much wetter, rain seeped down and filled these spaces. The climate changed and desert took over above, but much of the water remained, with very little recharge in today’s dry climate.

The Nubian Sandstone Aquifer stretches beneath Libya, Egypt, Sudan and Chad and is the world’s largest known reserve of ancient groundwater, much of it fresh water. In Libya, the water is pumped up and carried through the Great Man-Made River towards coastal cities and farmland, in one of the world’s largest irrigation projects.

Above: sand moving with the wind. Below: sandstone that has held rain for tens of thousands of years.