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The Nile Valley
A green ribbon through the desert, holding a hundred million people
Nearly all Egyptians live on a small fraction of Egypt. That extraordinary compression is the Nile Valley: a green ribbon of floodplain, rarely more than 20 kilometers wide and often far less, threading north through the eastern Sahara before fanning into the delta at the Mediterranean. The terms are worth keeping straight. The Nile is the river; the Nile Valley is the inhabited strip of silt the river built, and the desert that hems it in on either side. Seen from orbit at night, it is one of the most legible human patterns on Earth: a bright, narrow line unfurling across black emptiness, with a blaze of light at the end of it.
Measured with the river from its Ethiopian and Ugandan headwaters, the system runs some 6,650 kilometers, though the classic inhabited ribbon through Sudan and Egypt is a fraction of that. The floodplain is a trench cut into desert plateaus, flanked by limestone and sandstone escarpments a few hundred meters high, and the soil is imported: silt carried down by the Blue Nile from the Ethiopian Highlands and dropped each summer. The annual inundation ended in 1970 with the Aswan High Dam, which traded flood control and electricity for a river that no longer fertilizes its own fields. The delta, once growing seaward, is now subsiding and salting as the sea rises against it.
Farming villages along this strip coalesced into one of the earliest states on Earth, and pharaonic Egypt spent three thousand years measuring the river's rise, because a low flood meant famine and a high one ruin. Nilometers, granaries and a bureaucracy all grew out of that single anxiety. The dependence has not ended, only changed shape. Egypt still draws the overwhelming majority of its water from the Nile, while upstream Ethiopia has built the Grand Ethiopian Renaissance Dam on the Blue Nile, a project Cairo treats as an existential question and Addis Ababa as its right to develop. With more than 100 million people packed onto the ribbon, the arithmetic of water here is unforgiving.