Sudan is situated in northern Africa, with a 853 km (530 mi) coastline bordering the Red Sea. It has land borders with Egypt, Eritrea, Ethiopia, South Sudan, the Central African Republic, Chad, and Libya. With an area of 1,886,068 km2 (728,215 sq mi), it is the third largest country on the continent (after Algeria and Democratic Republic of the Congo) and the sixteenth largest in the world.
Sudan lies between latitudes 8° and 23°N. The terrain is generally flat plains, broken by several mountain ranges. In the west the Deriba Caldera (3,042 m or 9,980 ft), located in the Marrah Mountains, is the highest point in Sudan. In the east are the Red Sea Hills.
The Blue and White Nile rivers meet in Khartoum to form the River Nile, which flows northwards through Egypt to the Mediterranean Sea. The Blue Nile’s course through Sudan is nearly 800 km (497 mi) long and is joined by the Dinder and Rahad Rivers between Sennar and Khartoum. The White Nile within Sudan has no significant tributaries.
There are several dams on the Blue and White Niles. Among them are the Sennar and Roseires Dams on the Blue Nile, and the Jebel Aulia Dam on the White Nile. There is also Lake Nubia on the Sudanese-Egyptian border.
Rich mineral resources are available in Sudan including asbestos, chromite, cobalt, copper, gold, granite, gypsum, iron, kaolin, lead, manganese, mica, natural gas, nickel, petroleum, silver, tin, uranium and zinc.
The amount of rainfall increases towards the south. The central and the northern part have extremely dry desert areas such as the Nubian Desert to the northeast and the Bayuda Desert to the east; in the south there are swamps and rainforest. Sudan’s rainy season lasts for about three months (July to September) in the north, and up to six months (June to November) in the south.
The dry regions are plagued by sandstorms, known as haboob, which can completely block out the sun. In the northern and western semi-desert areas, people rely on the scant rainfall for basic agriculture and many are nomadic, travelling with their herds of sheep and camels. Nearer the River Nile, there are well-irrigated farms growing cash crops. The sunshine duration is very high all over the country but especially in deserts where it could soar to over 4,000 h per year.
Desertification is a serious problem in Sudan. There is also concern over soil erosion. Agricultural expansion, both public and private, has proceeded without conservation measures. The consequences have manifested themselves in the form of deforestation, soil desiccation, and the lowering of soil fertility and the water table.
The nation’s wildlife is threatened by hunting. As of 2001, twenty-one mammal species and nine bird species are endangered, as well as two species of plants. Endangered species include: the waldrapp, northern white rhinoceros, tora hartebeest, slender-horned gazelle, and hawksbill turtle. The Sahara oryx has become extinct in the wild.