Niger Delta. The Resource Wealth of the Niger Delta

The Niger is Africa's third largest river, 4,167 kilometers long. The delta into which the Niger drains before it enters the Atlantic Ocean in a complex of streams is a huge floodplain in southeastern Nigeria. The Nile delta is a vast sedimentary basin constructed over time through successive thick layers of sediments dating back 40-50 million years to the Eocene epoch. Its immense coastal plain covers almost 70,000 square kilometers.

The Niger delta has been defined for a variety of political, ecological, and geological purposes, but the conventional geographical perimeter extends from the Benin River in the west to the Imo River in the east and from the southernmost tip at Palm Point near Akassa to Aboh in the north, where the Niger River bifurcates into its two main tributaries. This area represents roughly 25,900 square kilometers, about 2.8 percent of Nigeria's land area. It is a classic arcuate (bow-shaped) delta, typically below the 15-meter contour across its entire extent.

The Niger delta has four major ecological zones: coastal sand barrier islands, mainly along the coastline; western African lowland equatorial monsoon, marked mainly by vast stretches of floodplain and riverine swamp; western African freshwater alluvial equatorial monsoon, a levee forest area; and western African brackish-water alluvial equatorial monsoon, dominated by mangroves and an area of transition between mangroves and freshwater alluvial equatorial monsoon. Nigeria's mangroves are the largest in Africa, and over half of them are in the Niger delta.

The Resource Wealth of the Niger Delta. The delta is endowed with very substantial hydrocarbon deposits. Crude-oil production from the delta runs at almost 2 million barrels per day; this accounts for roughly 90 percent of Nigerian export revenues. Nigeria is the largest producer of petroleum in Africa, is among the world's top ten oil producers, and is a member of the Organization of Petroleum Exporting Countries (OPEC).

The major drainage systems of the delta consist of seven discrete river systems that lie squarely in the wet equatorial climatic belt. Cloud cover is high, relative humidity is always above 80 percent, and rain falls year round with the exception of a short dry spell in January and February. Soils are hydromorphic (poor in oxygen due to their development in a wet environment) and poorly drained.

There are few remaining areas of pristine vegetation, and the contemporary biogeography is largely composed of a mosaic of arable farmlands (planted in cassava, maize, and yams), tree crops (oil palm, rubber, cocoa, plantain), and patches of natural vegetation. The remaining natural vegetation includes lowland rain forest, freshwater swamps, tidal mangroves, salt marsh and tidal mudflats, and coastal forest on the barrier sand ridges.

The Effect of Dams. The construction of dams on the Niger, beginning with Kainji Dam in central Nigeria in 1968, triggered a process that began to alter the Niger delta's hitherto- dynamic and self-regulating ecosystem. Prior to Kainji and several other dams in its wake, there was a fine balance between the constant flooding, erosion, and sediment deposition. Upstream dams led to the loss of 70 percent of sediment transport from the Niger and its tributaries. Sediment deposits are rising again, however, due mainly to the accumulation of silt in the dams, which has led to the decrease in the capacity of the reservoirs to obstruct river flow.