Geography and Topography
There is no modern political entity called Nubia. The area known by this term lies today partly in Egypt and partly in the
Republic of the Sudan. A large portion of the northern part of ancient Nubia currently lies submerged under the
reservoir formed behind Egypt's High Dam at Aswan. The following information describes the geographic and
topographic area as it existed before the construction of the High Dam.
Nubia's most conspicuous topographic feature is the Nile, which flows through the country on its way north to the Mediterranean Sea. Throughout Nubia, the flow of the river is periodically broken up by cataract, areas where outcroppings of rock prevent easy water navigation. These cataracts, six in total, are the result of Nubian geology.
Two major stone formations underlie the Nubian stretches of the Nile: Nubian sandstone and granite. Where the river passes through the granite formation, the valley is narrow, with sharp cliffs on either side and little alluvial soil for cultivation. Where the river flows over sandstone, the valley is broader and generally has a wider alluvial floodplain, suitable for formations or where granite outcroppings appear in sandstone areas.
The cataracts serve as markers of Nubia's borders. The First Cataract, just to the south of Aswan, marks the northern planting crops. The cataracts mark places where the Nile crosses a border between the sandstone and granite boundary of Nubia. The southern border, though it fluctuated over time, lies near the Sixth Cataract. The eastern and western borders are generally marked by the extent of the cultivated fields on either side of the river. The cataracts also divide Nubia into different zones, which differ from one to another topographically. Nubia is generally divided into Lower Nubia, Upper Nubia, and Southern Nubia.
The landscape in Lower Nubia is quite different from that of Upper Nubia. The Nile Valley in Lower Nubia is similar to the Nile Valley in Egypt. The river here is broad and easily navigated, with a wide floodplain available for cultivation. Upper Nubia on the other hand, often presents a much harsher environment. Based on topography, Upper Nubia and Southern Nubia can be divided into five zones: (1) Batn el Hajar, (2) Abri-Delgo Reach, (3) Dongola Reach, (4) Abu Hamed Reach, and (5) Shendi Reach. Each of these zones, defined by cataracts, display a different type of riverine environment.