The Nile flood brings with it a staggering 140 million tonnes of fertile volcanic soil which over thousands of years has provided the Nile Delta with the most fertile soil in Africa. In 1971, when the Aswan Dam was built and Lake Nasser created, the natural flooding cycle was changed forever and nutrient-rich sediments no longer reach the delta. As a result, salt water seeps back into the freshwater and fish species both in the Nile and in the Eastern Mediterranean have depleted. However, Lake Nasser does provide fresh water to millions of people.

The Ancient Egyptians were at the mercy of the Nile. If the flood failed they faced drought and starvation - a 20-year drought destroyed the Old Kingdom in around 2,200BC. Even a good flood and abundant crops could bring danger. When locust populations reach a critical density, chemical and physical cues cause radical alteration of their behaviour. Terrifying swarms appear, carried by the warm desert winds. One square kilometre can contain 50 million locusts, with a swarm covering 4m every second. They devour everything in their paths: crops, grain stores and even larders. Their faeces contaminate the little they leave behind and those who eat it are poisoned.

Much of the greenery in the delta and along the banks of the river is made up of the papyrus reed which the ancient Egyptians used for writing. Surviving papyrus scrolls provide us with much of our knowledge about the land of the pharaohs. Papyrus beds are also wildlife havens. Weaver birds turn the papyrus flower heads into building material for their nests, constructing woven cities above the papyrus marsh.

As a growing modern society, Egypt has demanded more and more from the Nile. Waiting for the inundation seemed out-dated, so in 1902 the British built a dam at Aswan. But the flood was only brought fully under control with the completion of the high Aswan dam further upstream, in 1971. This impressive feat of engineering guarantees year-round irrigation of crops and more electricity than the country can use, but it comes at a price. The rich silt from Ethiopia now builds up in Lake Nasser, behind the dam. As a result, Egypt has to import fertilisers for the fields of the Nile valley.

Bringing a yearly gift of water and rich volcanic soil the Nile transforms the desert into a fertile paradise. From a satellite the path of the Nile is clearly visible - a ribbon of fertile land, defiant against the endless expanses of surrounding desert. Acting like a giant oasis set in the middle of the desert, the Nile concentrates wildlife and acts as a staging post for thousands of birds on a migration corridor between Europe and Africa.