Niger

Geography

The Niger River is a relatively clear river, carrying only a tenth as much sediment as the Nile because the Niger's headwaters lie in ancient rocks that provide little silt. Like the Nile, the Niger floods yearly; this begins in September, peaks in November, and finishes by May. An unusual feature of the river is the Inner Niger Delta, which forms where its gradient suddenly decreases. The result is a region of braided streams, marshes, and large lakes; the seasonal floods make the Delta extremely productive for both fishing and agriculture.

The river loses nearly two-thirds of its potential flow in the Inner Delta between Ségou, and Timbuktu to seepage and evaporation. The water from the Bani River, which flows into the Delta at Mopti, does not compensate for the losses.

History

At the end of the African humid period around 5,500 years before present, the modern Sahara Desert, once a savanna, underwent desertification. As plant species sharply declined, humans migrated to the fertile Niger River bend region, with abundant resources including plants for grazing and fish. Like in the Fertile Crescent, many food crops were domesticated in the Niger River region, including yams, African rice (Oryza glaberrima), and pearl millet. The Sahara aridification may have triggered, or at least accelerated, these domestications. Agriculture, as well as fishing and animal husbandry, led to the rise of settlements like Djenné-Djenno in the Inner Delta, now a World Heritage Site.

Climate

As part of the West Africa Sahel region, the Niger River has a hot climate characterized by very high temperatures year-round; a long intense dry season from October to May; and a brief, irregular rainy season linked to the West African monsoon.