Action contre la désertification

The Great Oasis

The New Yorker About a third of all land on earth has been claimed by desert almost twenty million square miles and the percentage is likely to increase with global warming. The desert always menaces, the French botanist Andre Aubreville warned.


In the Al Hajar Mountains of northern Oman, at the eastern edge of the Arabian Desert, high above the white terraces and minarets of Muscat, rain comes rarely and then in floods. Hajar means “rock” in Arabic, and the mountains are made of little else—a fractal landscape of umber and dusty limestone, thrust from the sea more than sixty-five million years ago and still shaped more by salt water than by sweet. When the clouds burst, as they do a few times a year, the rain skitters from the slopes like oil from a griddle, gathers into rivulets and swiftly moving sheets, and tumbles into the wadies that wind between peaks. The ancient Omanis built networks of aqueducts and underground falajes to funnel the water to their crops. Oases of mango, date palm, sweet lemon, and lime still survive on this system, their fruit knuckled in on itself against the heat, smaller and more pungent than their Indian ancestors. But on most slopes the only traces of green are a few umbrella-thorn trees, Acacia tortilis, anchored to the bare rock. Their roots can descend more than a hundred feet in search of groundwater. [more]