Niger River

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.

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. The average loss is estimated at 31 km³/year but varies considerably between years. The river is then joined by various tributaries but also loses more water to evaporation. The quantity of water entering Nigeria was estimated at 25 km³/year before the 1980s and at 13.5 km³/year during the 1980s.

The most important tributary is the Benue River which merges with the Niger at Lokoja in Nigeria. The total volume of tributaries in Nigeria is six times higher than the inflow into Nigeria, with a flow near the mouth of the river standing at 177.0 km³/year before the 1980s and 147.3 km³/year during the 1980s.

Course

The Niger takes one of the most unusual routes of any major river, a boomerang shape that baffled geographers for two centuries. Its source (Tembakounda) is 240 km (150 mi) inland from the Atlantic Ocean, but the river runs directly away from the sea into the Sahara Desert, then takes a sharp right turn near the ancient city of Timbuktu and heads southeast to the Gulf of Guinea. This strange geography apparently came about because the Niger River is two ancient rivers joined together. The upper Niger, from the source west of Timbuktu to the bend in the current river near Timbuktu, once emptied into a now dry lake to the east northeast of Timbuktu, while the lower Niger started to the south of Timbuktu and flowed south into the Gulf of Guinea. Over time upstream erosion by the lower Niger resulted in stream capture of the upper Niger by the lower Niger.

The northern part of the river, known as the Niger bend, is an important area because it is the major river and source of water in that part of the Sahara. This made it the focal point of trade across the western Sahara and the centre of the Sahelian kingdoms of Mali and Gao. The surrounding Niger River Basin is one of the distinct physiographic sections of the Sudan province, which in turn is part of the larger African massive physiographic division.

Drainage basin

The Niger River basin, located in western Africa, covers 7.5% of the continent and spreads over ten countries.

Niger River basin: areas and rainfall by country

Discharge

Average discharge of the Niger River at Niger Delta (period from 2010 to 2018):

Tributaries

The main tributaries from the mouth:

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.

The region of the Niger bend, in the Sahel, was a key origin and destination for trans-Saharan trade, fueling the wealth of great empires such as the Ghana, Mali, and Songhai Empires. Major trading ports along the river, including Timbuktu and Gao, became centers of learning and culture. Trade to the Niger bend region also brought Islam to the region in approximately the 14th century CE. Much of the northern Niger basin remains Muslim today, although the southern reaches of the river tend to be Christian.

Classical writings on the interior of the Sahara begin with Ptolemy, who mentions two rivers in the desert: the "Gir" (Γειρ) and farther south, the "Nigir" (Νιγειρ). The first has been since identified as the Wadi Ghir on the north-western edge of the Tuat, along the borders of modern Morocco and Algeria. This would likely have been as far as Ptolemy would have had consistent records. The Ni-Ger was likely speculation, although the name stuck as that of a river south of the Mediterranean's "known world". Suetonius reports Romans traveling to the "Ger", although in reporting any river's name derived from a Berber language, in which "gher" means "watercourse", confusion could easily arise. Pliny connected these two rivers as one long watercourse which flowed (via lakes and underground sections) into the Nile, a notion which persisted in the Arab and European worlds – and further added the Senegal River as the "Ger" – until the 19th century.

While the true course of the Niger was presumably known to locals, it was a mystery to the outside world until the late 18th century. The connection to the Nile River was made not simply because this was then known as the great river of "Aethiopia" (by which all lands south of the desert were called by Classical writers), but because the Nile like the Niger flooded every summer. Through the descriptions of Leo Africanus and even Ibn Battuta – despite his visit to the river – the myth connecting the Niger to the Nile persisted.

Many European expeditions to plot the river were unsuccessful. In 1788 the African Association was formed in England to promote the exploration of Africa in the hopes of locating the Niger, and in June 1796 the Scottish explorer Mungo Park was the first European to lay eyes on the middle portion of the river since antiquity (and perhaps ever). He wrote an account in 1799, Travels in the Interior of Africa. Park proposed a theory that the Niger and Congo were the same river. Although the Niger Delta would seem like an obvious candidate, it was a maze of streams and swamps that did not look like the head of a great river. He died in 1806 on a second expedition attempting to prove the Niger-Congo connection. The theory became the leading one in Europe. Several failed expeditions followed; however the mystery of the Niger would not be solved for another 25 years, in 1830, when Richard Lander and his brother became the first Europeans to follow the course of the Niger to the ocean.

In 1946, three Frenchmen, Jean Sauvy, Pierre Ponty and movie maker Jean Rouch, former civil servants in the African French colonies, set out to travel the entire length of the river, as no one else seemed to have done previously. They travelled from the beginning of the river near Kissidougou in Guinea, walking at first till a raft could be used, then changing to various local crafts as the river broadened and changed. Two of them reached the ocean on March 25, 1947, with Ponty having left the expedition at Niamey, somewhat past the halfway mark. They carried a 16mm movie camera, the resulting footage giving Rouch his first two ethnographic documentaries: "Au pays des mages noirs", and "La chasse à l'hippopotame". A camera was used to illustrate Rouch's subsequent book "Le Niger En Pirogue" (Fernand Nathan, 1954), as well as Sauvy's "Descente du Niger" (L'Harmattan, 2001). A typewriter was brought as well, on which Ponty produced newspaper articles he mailed out whenever possible.

Management and development

The water in the Niger River basin is partially regulated through dams. In Mali the Sélingué Dam on the Sankarani River is mainly used for hydropower but also permits irrigation. Two diversion dams, one at Sotuba just downstream of Bamako, and one at Markala, just downstream of Ségou, are used to irrigate about 54,000 hectares. In Nigeria the Kainji Dam, Shiroro Dam, Zungeru Dam, and Jebba Dam are used to generate hydropower.

The water resources of the Niger River are under pressure because of increased water abstraction for irrigation. The construction of dams for hydropower generation is underway or envisaged in order to alleviate chronic power shortages in the countries of the Niger basin. The FAO estimates the irrigation potential of all countries in the Niger river basin at 2.8 million hectares. Only 0.93m hectares (ha) were under irrigation in the late 1980s. The irrigation potential was estimated at 1.68m ha in Nigeria 0.56m ha in Mali, and the actual irrigated area was 0.67m ha and 0.19m ha.

Trade routes and ecological importance in West Africa

The Niger River is a key river of West Africa and it is considered the third-longest river in Africa. The river extends approximately 2,600 miles from its source in the Fouta Djallon Highlands of Guinea through Mali, Niger, Benin, and Nigeria before emptying into the Gulf of Guinea. For close to centuries, The Niger River has been a vital economic lifeline, transportation for the peoples and the states of West Africa.

Trade routes of the Niger River

According to history, the Niger River has served as important trade and transportation corridors in West Africa. The river flows through Mali, Guinea, Niger, Benin, and Nigeria, the river facilitated the movement of goods and people across the region long before the invention of modern transportation systems like ships, and aeroplanes. During the middle ages, the river supported Ghanaians, Malians, and the Songhai Empires by connecting inland settlements with trans-Saharan trade routes.

Goods traded

The commodities transported along the Niger River were:

1. Gold
2. Salt
3. Kola nuts
4. Agricultural produce
5. Fish
6. Livestock
7. Textiles
8. Slaves

In recent times, the Niger River remains an important inland waterway supporting commerce, trade and transport. The river transport contributes to economic development, particularly in rural areas.

Ecological importance

One of Africa's most significant ecological systems is the Niger River. The Niger river basin supports many diverse habitats, including aquatic life, floodplains, savannas and forest reserves. The Inner Niger Delta, serves as a habitat for large species of migratory birds, fish, reptiles and mammals. The Inner Niger Delta covers approximately 20,000 km² in the wet seasons and 3,900 km² in the dry season, serving as a vital resource for fishing, farming and pastoralism that sustains millions of lives.

The Niger River is also the major source of freshwater for domestic use, irrigation and hydroelectric power generation. The Niger River waters irrigates extensive agricultural produce, such as millet, rice and vegetable cultivation. Additionally, the river helps regulate local climates by maintaining wetlands

The Niger River faces multiple challenges including climate change, pollution, deforestation, overfishing and the construction of dams. These challenges pose a threat to both the ecological health of the river and the livelihoods of the populations that depends on its resources and life. In essence, sustainable management of the Niger River Basin is considered essential for the long-term economic and environmental safety of West Africa. Management authorities like the Niger Basin Authority (NBA) seeks to address these challenges to encourage management of this vital waterway. Another regulatory authority is the Integrated Water Resource Management (IWRM) is recognised as a body that promotes sustainable resource use across the basin's nine countries.