Niger basin
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The many faces
of the Niger River
The Niger is the
third-longest
river in Africa
after the Nile
and the Congo;
Subject to a tropical condition
in its upper basin, the Niger River
becomes the Inner Delta in Mali, where
it loses about half of its water by
evaporation and infiltration into the soil.
it crosses the Sahel and winds through
the Sahara before heading south where
it pours their water through the many
branches of a huge delta in the Gulf
of Guinea in Nigeria.
In this delta where a million people
live, the human activities follow the
rhythm of floods: fishing at high waters
and grazing and arable farming with
low water. Along the Niger’s course,
Each of the river’s ‘landscapes’
behaves differently based on the climate,
precipitation patterns, the shape
of drainage basins, infrastructures
on the river and human activities.
DID YOU KNOW?
it runs for
4,200 km
in West Africa.
It presents many
different faces
along its length.
Canoes designed for carrying passengers from one side
of the river to the other near Mopti.
Manatee Trichechus senegalensis.
The Inner Niger Delta is a vast, biodiverse
flood zone, where hippos, manatees
and more can be found.
IDENTITY CARD
Source: the Tingi hills
Mouth: Gulf of Guinea - Atlantic Ocean
Length: 4,184 km
Average discharge
at mouth: 5,600 m3/s
Surface of drainage basin:
1.2 million km²
The Inner Niger Delta
around Lake Débo.
Oil exploitation in the Niger
River Delta poses serious
environmental problems with
almost permanent oil slicks.
Little egret catching a fish. The Inner Niger Delta
is West Africa’s largest wintering area for birds. Researchers
have recorded 250 species there.
Countries: Sierra Leone, Guinea,
Côte d’Ivoire (Ivory Coast), Burkina Faso,
Mali, Niger, Benin, Nigeria,
Cameroon, Chad.
Bamba Market in the Gao region of Mali. Watercourses
are very important for the economy, allowing the goods to be transported
from the production site to the trading area.
The basin’s population is likely
to double in twenty years
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Niger basin
The vagaries
of floods
The River Niger’s water resources
and its main tributaries along the right
bank such as Bani, depends mainly
on the upper basin in Guinea, Mali and
Côte d’Ivoire. Precipitation is more abundant
in this region than in areas of the Sahel
and the Sahara. However, it is uneven
causing a great variability in the flow.
Since 1970, the reduction of rainfall
caused a sustained decline in groundwater
resources and a reduction of the flooded
areas in the delta.
The impact of climate change in the Niger
basin may also increase and decrease
rainfall and discharge, varying locally based
on geology and soils.
The abundant flow favours fishing,
navigation and irrigation throughout
the course of the river, and in particular
in the Inner Niger Delta. However,
devastating floods regularly take place,
such as in 1967 in Bamako, 1994 in the Inner
Delta, 2001 on the banks of the Sankarani,
and in 2010 and 2012 in Niamey.
These are essentially caused by heavy
runoff from bare soil resulting from drought
and an increase of cultivated land, or by
flooding of urban zones on the riverbed.
RESEARCH
The aim of the AMMA-Catch observatory is to have a better
understanding of the phenomenon of West Africa monsoon
and its impact on the environment. Researchers are carrying out
a long-term monitoring of vegetation and the water cycle as well as
interaction with climate. They use models of the hydrology and
the ground-atmosphere exchange in order to evaluate their role
and to anticipate rainfall and vegetation dynamics. In today’s current
context of climate change and land use, these data are vital to plan
for the future economic development of the region.
Climate change
and human
activities,
land use,
irrigation and
dams lead
to modification
of the Niger
River’s patterns,
in turn causing
reduced water
reserves during
dry season and
an increased
risk of flooding
and soil erosion.
Upstream, in the Guinean side of the river, precipitation is extremely
heavy, approximately 2,000 mm/year.
340,000 people were affected, and 44 killed,
following heavy flooding in August 2012
in Niamey in Niger.
In the Sahelian and Saharan parts of the river, rainfall is rarer
and more irregular, with less than 600 mm/year.
The 2001 floods on the banks of the Sankarani
almost completely destroyed the banana
plantations.
‘Waterside’ houses in Bamako. The extension
of habitat into high-risk areas and the combination
of climate change and human activities explains
the adverse effects of some floods, particularly
in the Sahel.
In August 2012, the Niger River
reached its highest level since 1929
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Niger basin
The fertile Niger
Irrigated crops, particularly rice
agriculture were developed around
reservoirs and traditionally in flood plains
and around the river. The motor-powered
pumps, commonly use during the dry
season, allows small family plots to be
irrigated to grow rice and vegetables.
Building large hydroelectric dams and
the increase in water withdrawal will affect
the river’s flows and will require better
water management. The river’s behaviour
has a particular influence on the scope
of the flooding in the Inner Delta
and therefore in the agricultural yields.
Most fishing in the basin is carried out
by craftsmen. Professional fishermen, such
as the Bozo, are located along the river
and on the Inner Delta.
Farming communities also occasionally
practise fishing. The fish stocks in the delta
vary each year depending on flood levels.
Extreme droughts, but also more intense
fishing and heavy catching of young fish,
have increased the pressure on this resource.
RESEARCH
Over several decades, the IRD has been working in the Niger
River Basin in order to improve understanding of pluviometry
and hydrological patterns subject to climatic and humans’ influences.
These data allow better understanding and optimisation of agricultural
practices. The IRD has taken part in CGIAR projects (Challenge Program on Water and Food, BFP Niger), HydroDIN, and Niger-Loire:
governance and culture (UNESCO) at the French national research
agency ANR RESSAC, and the ILEE federal research institute.
From the Guinean
forest to the
swamps at its
mouth, passing
through the great
extensions of dry
lands of the Sahel
and the deserts
of the Sahara,
Niger River
basin is home
to more than
100 million
people who make
a living from
rain-fed and
The life of Peul herds people in the Inner
Delta are built around the cycle
of transhumance. They follow the floods
and high waters in the rainy season, then
the gradual drying-up of the plains
and secondary branches.
Motor-powered pumps in the Kouakourou
region. This practice allows more diverse
crops (mainly bananas, but also mangos,
grapefruit, etc.).
The Niger River is an essential source
of agricultural water in the most arid areas.
The basin has a population of 50 million, and
in rural areas, the majority of people are arable
and livestock farmers.
irrigated
agriculture,
livestock farming,
and fishing.
The Inner Niger Delta is a vast, biodiverse
flood zone, home to 120 species of fish.
Collective fishing in the Bolé pond,
in the Niandan River.
Bozo fisherman hut, a provisional camp
in the Inner Niger Delta.
Harvesting sorghum in Koré
Maïroua in Niger. Most agriculture
in the Niger basin is rain-fed,
where dry cereal crops are followed
by root crops based on rainfall.
Irrigation represents only 5%
of agricultural surface area in the basin
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Niger basin
Living and developing
alongside the river
Aware of the socio-economic challenges
and concerned about tensions that can
arise between the various users, the nine
states along the river were associated
creating the River Niger Commission
in 1964, and then in 1980 the Niger Basin
Authority. This intergovernmental
organization ensures cooperation among
its members to achieve fair and sustainable
management of the 1.2 million km²
of the basin.
Large hydro-agricultural and hydroelectric
developments on the Niger and its tributaries
remain few and unequally distributed.
However, several major projects are currently
underway: the Niger Basin Authority is making
significant investments in order to irrigate
15,000 km² by 2025, including the Fomi Dam
in Guinea and the Taoussa Dam in Mali.
Alongside these larger projects, smaller
hydraulic facilities have proliferated along
the riverbanks since the drought of 1980s.
These small dams and pumps are continuing
to increase in number, and are likely to have
a non-negligible impact on the hydrological
balance of the basin and should therefore
be taken into account in terms of water
management.
RESEARCH
The main objective of Gire 2 project is to provide the Niger Basin
Authority the means to ensure an effectively monitoring of water
resources and large hydraulic facilities to perform a peaceful,
integrated and coordinated management, including: functional
hydrological equipment, capacity building of officers, operational
databases and improve systems for processing and dissemination
of information and data.
The nine
countries
which share
the Niger basin
depend mostly
on the river
and its tributaries
for agriculture
and drinking
water supplies,
but also for
energy, transport,
industry, tourism,
and other
purposes.
Since the population is expected to double
within 20 years from now and hydraulic
facilities are unevenly spread over the territories,
there are concerns that tensions will rise
between users and countries.
An ethnic Fula Rimaybe farmer is waiting
for the first rains. In the Inner Niger Delta,
flooding is essential to develop agro-pastoral
activities.
Since 1982, the operation of Sélingué Dam has altered the Sankarani River (a tributary)
and up to the Inner Niger Delta. Although the discharge in times of flooding is only slightly
reduced, the impact on the dry season is much more important since water is released
in the dry season to ensure a water flow that enables navigation and fishing.
Irrigated areas near the Sankarani, a tributary
of the Niger. The dam, as well as producing
electricity, creates a store of water used
to irrigate a vast field area.
Around 500 small hydraulic facilities have been
built on the Bani River drainage basin in Mali.
It is highly likely that they will affect flow behaviour,
but this is impossible to quantify due to the lack
of information on the size of the reservoirs,
how they are operated, and the water usage.
The Markala Dam is one
of the largest on the Niger River
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