Niger

Niger, river, western Africa, rising in Guinea and flowing for about 4,180 km (2,600 mi) through Mali, Niger, and Nigeria to the Gulf of Guinea. The Benue, which joins the Niger at Lokoja in Nigeria, is its chief tributary. The Niger delta (about 36,300 sq km/14,000 sq mi in area) is the largest in Africa; it has a coastline of nearly 190 km (120 mi). Port Harcourt is located on the delta. The Niger also forms a vast interior delta in central Mali. The river is navigable almost all year as far upstream as Lokoja; it is seasonally navigable in other areas. The Niger and its tributaries drain a total area of about 1.2 million sq km (463,000 sq mi). Rainfall varies dramatically in this area, from an annual average of 4,064 mm (160 in) per year in the delta, to 254 mm (10 in) at Timbuktu. The average discharge of the river at its mouth is about 6 million litres (1.3 million gallons) per second.

The upper Niger was a core area of the old empires of Mali and Songhai; during this time Timbuktu, at the great bend of the river, was a major cultural and commercial centre. Western geographers long sought to establish the course of the Niger. The Scottish explorer Mungo Park determined in 1796 that the river flows east, and in 1830 the English brothers Richard Lander and John Lander proved that the Niger empties into the Gulf of Guinea. The “W” National Park, bordering the river in Niger, represents a transition zone between savannah and forest territory, and was designated a UNESCO World Heritage Site in 1996.