Like HowStuffWorks on Facebook!

How the Nile River Works

The Long and Winding River
2008 HowStuffWorks

The Nile boasts a long and complex route, winding its way through nine countries­ and a myriad of landscapes, including swamps, savannas, desert, rain forests and mountain highlands. The Nile owes its great length to the union of two main tributaries: the White Nile and the Blue Nile. The White Nile flows from the newly established source in Rwanda through the original source of Lake Victoria. When it reaches Khartoum in the country of Sudan, it joins forces with the Blue Nile, which originates in the Ethiopian mountains. The Nile's only other large tributary is the Atbara River, which joins the Nile in the eastern portion of Sudan. Although the White Nile -- the easier portion to navigate -- is considered the longer section of river, the Blue Nile provides roughly two-thirds of the total water supply to the river.

Both tributaries are named for the color of the water they contribute. At its source, the Blue Nile is bright blue, then darkens in Sudan where it begins to carry black sediment. The White Nile carries light gray sediment, turning the water more whitish-gray in color.

After the Blue Nile and the White Nile join forces in Khartoum, the river passes through six cataracts (rapids) on the way to Aswan. These rapids form when the river encounters igneous rock formations. The cataracts make it extremely difficult to navigate these sections of the river, effectively creating a natural boundary. Once the Nile makes its way to Egypt it splits into two branches -- the Damietta on the east and Rosetta on the west side. This forms the Nile Delta, through which the branches exit Africa and enter the Mediterranean Sea.

Another interesting characteristic of the Nile's course is the Great Bend, a U-shaped bend in course that takes place between the Nile Delta and the Sudanese border. This bend causes the river to suddenly flow west to east, only to then turn around and go back the other way.

A river as mighty as the Nile has obvious effects on the people living nearby. The people of Ancient Egypt certainly prospered, but how does the Nile factor in? Read the next page to find out.

More to Explore