Egypt has a desert land of more than ninety percent. The land has a less amount of rainfall in an entire year than many countries experience in a single afternoon storm. But it's unfortunate that the longest river in the world, the life-giving Nile, flows nearly a thousand miles through the length of Egypt, and “everything grows where the water flow.
For thousands of years, Egyptian farmers had no need to fertilize their land because the Nile did it for them when it overflowed its banks each summer, spilling millions of tons of silt onto its flood plain. This silt contained all the nutrients the crops needed. The yearly floods left the ancient Egyptians grateful, but puzzled.
Satellite images show lush green along the banks of the Nile, contrasting starkly with the surrounding desert.
Why did the Nile never dry up? The river always flooded in summer, the driest time of year, so where did all the precious water come from?
The secret of the flooding lay in the different climates of the two branches which fed the Nile. The White Nile originated in a tropical rain forest in the tiny African country of Burundi, receiving enough precipitation throughout the year to ensure a steady flow of water through Egypt. The Blue Nile’s source was in Ethiopia’s highlands where 60 inches of rain fell between May and October.
