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[[Africa Groundwater Atlas Home | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]]  >> Hydrogeology of Niger
 
[[Africa Groundwater Atlas Home | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]]  >> Hydrogeology of Niger
 
 
  '''Lire cette page en français: [[Hydrogéologie du Niger | Hydrogéologie du Niger]]''' [[File: flag_of_france.png  | 50px]]
 
 
[[File:CC-BY-SA_logo_88x31.png | frame | This work is licensed under a [https://creativecommons.org/licenses/by-sa/3.0/ Creative Commons Attribution-ShareAlike 3.0 Unported License]]]
 
  
 
Niger is the largest country in West Africa, with some 80% of its area within the Sahara desert. Since independence from French colonialism in 1958, the country has seen alternate periods of civil and military rule. Currently a multi-party democracy, Niger faces significant development challenges. It has one of the lowest literacy rates in the world.  
 
Niger is the largest country in West Africa, with some 80% of its area within the Sahara desert. Since independence from French colonialism in 1958, the country has seen alternate periods of civil and military rule. Currently a multi-party democracy, Niger faces significant development challenges. It has one of the lowest literacy rates in the world.  
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===General===
 
===General===
 
Niger is a landlocked country in West Africa, with mainly gentle relief.
 
  
 
{| class = "wikitable"
 
{| class = "wikitable"
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|Border Countries || Nigeria, Benin, Burkina Faso, Mali, Algeria, Libya, Chad.
 
|Border Countries || Nigeria, Benin, Burkina Faso, Mali, Algeria, Libya, Chad.
 
|-
 
|-
|Total Surface Area* || 1,266,700 km<sup>2</sup> (126 670 000 ha)
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|Total Surface Area* (km<sup>2</sup>) || 1,266,700
 
|-
 
|-
|Total Population (2015)** || 19,899,000  
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|Total Population (2015)** || 19,899,000
 
|-
 
|-
|Rural Population** (2015) || 16,290,000 (82%)
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|Rural Population** (2015) || 16,290,000
 
|-
 
|-
|Urban Population** (2015) || 3,609,000 (18%)
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|Urban Population** (2015) || 3,609,000
 
|-
 
|-
 
|Human Development Index (HDI) (highest = 1)** || 0.3483
 
|Human Development Index (HDI) (highest = 1)** || 0.3483
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<nowiki>*</nowiki> Source: World Bank
 
<nowiki>*</nowiki> Source: World Bank
 
<nowiki>**</nowiki> Source: [http://www.fao.org/nr/water/aquastat/main/index.stm FAO Aquastat]
 
<nowiki>**</nowiki> Source: [http://www.fao.org/nr/water/aquastat/main/index.stm FAO Aquastat]
 +
 +
Niger is a landlocked country in West Africa, with mainly gentle relief.
  
  
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This section provides a summary of the geology of Niger. The geology map below shows a simplified overview of the geology at a national scale. For more information on the datasets used in the map see the [[Geology | the Geology resource page]].
 
This section provides a summary of the geology of Niger. The geology map below shows a simplified overview of the geology at a national scale. For more information on the datasets used in the map see the [[Geology | the Geology resource page]].
 
[https://www.bgs.ac.uk/africagroundwateratlas/downloadGIS.html '''Download a GIS shapefile of the Niger geology and hydrogeology map'''].
 
  
 
''Other sources of geological information''
 
''Other sources of geological information''
  
A [https://inis.iaea.org/search/searchsinglerecord.aspx?recordsFor=SingleRecord&RN=39112006 geological map of the Republic of Niger at 1: 2 million scale], published in 1966, was published in paper form, and may be available from the Centre de Recherche Geologique et Miniere in Niamey.  
+
A [https://inis.iaea.org/search/search.aspx?orig_q=RN:3911200 geological map of the Republic of Niger at 1: 2 million scale], published in 1966, was published in paper form, and may be available from the Centre de Recherche Geologique et Miniere in Niamey.  
  
 
A [http://www.brgm.eu/project/geological-mining-information-system-niger BRGM project] in 2011 helped to set up a geographical information system (GIS) for geological and mining data, although it may not still be available.
 
A [http://www.brgm.eu/project/geological-mining-information-system-niger BRGM project] in 2011 helped to set up a geographical information system (GIS) for geological and mining data, although it may not still be available.
  
  
[[File:Niger_Geology4.png | center | thumb| 500px | Geology of Niger at 1:5 million scale. Based on map described by Persits et al. 2002 / Furon and Lombard 1964. For more information on the map development and datasets see the [[Geology | geology resource page]]. [https://www.bgs.ac.uk/africagroundwateratlas/downloadGIS.html Download a GIS shapefile of the Niger geology and hydrogeology map].]]
+
[[File:Niger_Geology3.png | center | thumb| 500px | Geology of Niger at 1:5 million scale. Based on map described by Persits et al. 2002 / Furon and Lombard 1964. For more information on the map development and datasets see the [[Geology | geology resource page]].]]
  
 
{| class = "wikitable"
 
{| class = "wikitable"
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|-
 
|-
 
|cross-basin
 
|cross-basin
||Unconsolidated Quaternary, undifferentiated
+
||Quaternary
||Unconsolidated sediments of Quaternary age cover much of the surface outcrop of Chad. Within the Chad Basin (see below), most Quaternary sediments belong to the Chad Formation. Within the Iullemeden Basin (see below) are extensive aeolian (dune) sands and alluvial sands and gravels in river valleys. There are also small outcrops of lacustrine silts and clays and evaporite deposits in former lake beds.  
+
||Away from the Chad and Iullemedan Basins (see below), relatively small outcrops of unconsolidated Quaternary sediments can be found, including: alluvial sands and gravels in river valleys; lacustrine silts and clays and evaporite deposits in former lake beds; and some small areas of aeolian dune sands.  
 
|-
 
|-
 
|Chad Basin
 
|Chad Basin
 
||Cretaceous-Quaternary
 
||Cretaceous-Quaternary
||The Chad Basin is a major geological feature: a sedimentary depositional basin that extends over large parts of a number of countries including Chad and Nigeria. In Niger, the Chad Basin covers most of the east and north of the country. The basin contains a great thickness of sedimentary rocks dating from the Cretaceous to Quaternary in age. These are more than 3,500 m thick at the thickest known points, but may be more. These sedimentary rocks are underlain by Precambrian bedrock.  
+
||The Chad Basin is a major geological feature: a sedimentary depositional basin that extends over large parts of a number of countries including Chad and Nigeria. In Niger, the Chad Basin covers much of the east and north of the country. The Basin contains a great thickness of sedimentary rocks dating from the Cretaceous to Quaternary in age - it is more than 3,500 m thick at its thickest known points, although the total thickness in Niger is uncertain. These sedimentary rocks are underlain by Precambrian bedrock.  
  
''Quaternary:'' the uppermost and youngest sediments in the Chad Basin belong to the Chad Formation, and are largely of Quaternary age. These range from a few tens of metres up to many hundreds of metres thick. The Chad Formation consists of unconsolidated fine to coarse grained sands and gravels with sandy clays. These include extensive aeolian (dune) sands, and relatively extensive clayey to sandy aluvial sediments in active and abandoned river channels. There are also lacustrine (lake and lake-margin), alluvial fan and deltaic deposits. Much of the sequence is sandy or gravelly, but there are frequent lacustrine clay layers. Abrupt changes in clay and sand content are common, and the sediments usually occur as overlapping lenses.  
+
The youngest and uppermost formation is the Chad Formation, largely of Quaternary age, which ranges from a few tens of metres up to many hundreds of metres thick. It consists of unconsolidated fine to coarse grained sands and gravels with sandy clays. These include extensive aeolian (dune) sands, and relatively extensive clayey to sandy aluvial sediments in active and abandoned river channels. There are also lacustrine (lake and lake-margin), alluvial fan and deltaic deposits. Much of the sequence is sandy or gravelly, but there are frequent lacustrine clay layers. Abrupt changes in clay and sand content are common, and the sediments usually occur as overlapping lenses.  
  
''Tertiary:'' the Chad Formation is underlain by the Continental Terminal formation, largely of Tertiary age, which consists of alternating, usually loosely consolidated, sandstones, siltstones, shales and mudstones.
+
The Chad Formation is underlain by the Continental Terminal formation, largely of Tertiary age, which consists of alternating, usually loosely consolidated, sandstones, siltstones, shales and mudstones.
  
''Cretaceous:'' below the Continental Terminal there may be consolidated sedimentary rocks of Cretaceous age, dominantly marine but some continental sediments - including sandstones, siltsones, marls/calcareous mudstones and limestones.
+
Below the Continental Terminal there may be consolidated sedimentary rocks of Cretaceous age, dominantly marine but some continental sediments - including sandstones, siltsones, marls/calcareous mudstones and limestones.
 
|-
 
|-
 
|Iullemeden (also called Niger) Basin
 
|Iullemeden (also called Niger) Basin
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||The Iullemeden Basin lies immediately west of the Chad Basin and covers most of the western part of Niger. The Basin extends beyond Niger to parts of Mali, Benin and northwest Nigeria (it is called the Sokoto Basin in northwestern Nigeria). The total sedimentary sequence in the basin reaches several thousand metres thick.
 
||The Iullemeden Basin lies immediately west of the Chad Basin and covers most of the western part of Niger. The Basin extends beyond Niger to parts of Mali, Benin and northwest Nigeria (it is called the Sokoto Basin in northwestern Nigeria). The total sedimentary sequence in the basin reaches several thousand metres thick.
  
''Quaternary'': the youngest and uppermost sediments in the basin are unconsolidated Quaternary sediments, including extensive aeolian (dune) sands and alluvial sediments - extensive sands and gravels. and more minor silts and clays. These are often thin, up to few metres thick at most.
+
The youngest and uppermost sediments in the basin are unconsolidated Quaternary sediments, including extensive aeolian (dune) sands and alluvial deposits. These are often thin, up to few metres thick.
  
''Tertiary'': sedimentary rocks of Tertiary age include poorly-consolidated/loosely cemented clays, siltstones and sandstones of continental origin. In some places are chalky limestones. The sandstone parts of this sequence form part of the so-named regional Continental Terminal 3 aquifer, the base of which is formed by a continuous clayey layer of few tens
+
Below this are Tertiary sedimentary rocks, including poorly-consolidated/loosely cemented clays, siltstones and sandstones of continental origin. In some places are chalky limestones. The sandstone parts of this sequence form part of the so-named regional Continental Terminal 3 aquifer, the base of which is formed by a continuous clayey layer of few tens
 
of metres thick (Vouillamoz et al, 2007).
 
of metres thick (Vouillamoz et al, 2007).
  
''Cretaceous'': the lower parts of the Iullemeden Basin sequence are of Cretaceous age, including: Upper Cretaceous argillaceous siltstones and clays; Cenomanian to Turonian marine and lagoonal limestones, dolomitic limestones and sandstones; and Middle to Upper Cretaceous coarse grained sandstones.  
+
The lower parts of the Iullemeden Basin sequence are of Cretaceous age, including: Upper Cretaceous argillaceous siltstones and clays; Cenomanian to Turonian marine and lagoonal limestones, dolomitic limestones and sandstones; and Middle to Upper Cretaceous coarse grained sandstones.  
 
|-
 
|-
 
|Mesozoic-Palaeozoic
 
|Mesozoic-Palaeozoic
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This section provides a summary of the hydrogeology of the main aquifers in Niger. More detailed information on specific aquifers can be found in some of the references listed at the bottom of this page.  
 
This section provides a summary of the hydrogeology of the main aquifers in Niger. More detailed information on specific aquifers can be found in some of the references listed at the bottom of this page.  
  
The hydrogeology map shows a simplified overview of the type and productivity of the main aquifers at a national scale (see the [[Africa Groundwater Atlas Hydrogeology Maps | Hydrogeology map resource page]] for more details).
+
The hydrogeology map shows a simplified overview of the type and productivity of the main aquifers at a national scale (see the [[Hydrogeology Map | Hydrogeology map resource page]] for more details).  
 
 
[https://www.bgs.ac.uk/africagroundwateratlas/downloadGIS.html '''Download a GIS shapefile of the Niger geology and hydrogeology map'''].
 
  
[[File:Niger_Hydrogeology4.png | center | thumb| 500px | Hydrogeology of Niger at 1:5 million scale. For more information on how the map was developed see the [[Africa Groundwater Atlas Hydrogeology Maps | Hydrogeology map]] resource page. [https://www.bgs.ac.uk/africagroundwateratlas/downloadGIS.html Download a GIS shapefile of the Niger geology and hydrogeology map].]].
+
[[File:Niger_Hydrogeology3.png | center | thumb| 500px | Hydrogeology of Niger at 1:5 million scale. For more information on how the map was developed see the [[Hydrogeology Map | Hydrogeology map]] resource page]].
  
 
====Summary====
 
====Summary====
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There are three main types of aquifer in Niger:  
 
There are three main types of aquifer in Niger:  
  
:- '''Unconsolidated sediments''' dominated by sands, sometimes with gravel, of alluvial or aeolian origin. Alluvial sediments in large valleys can form productive local aquifers. More extensive dune sands, such as the thick Chad Formation in the Chad Basin, form a regionally important aquifer.
+
:- Unconsolidated sediments dominated by sands, sometimes with gravel, of alluvial or aeolian origin. Alluvial sediments in large valleys can form productive local aquifers. More extensive dune sands, such as the thick Chad Formation in the Chad Basin, form a regionally important aquifer.
:- Loosely to strongly '''consolidated sedimentary rocks''': sandstones, limestones and siltstones of Mesozoic (Cretaceous-Tertiary) and Palaeozoic age.  
+
:- Loosely to strongly consolidated sandstones, limestones and siltstones of Mesozoic (Cretaceous-Tertiary) and Palaeozoic age.  
:- '''Precambrian Basement''' weathered/fractured aquifers, used locally in parts of western and central Niger.  
+
:- Precambrian Basement weathered/fractured aquifers, used locally in parts of western and central Niger.  
  
 
The most extensive and productive aquifers of Niger are sedimentary formations known as the Continental Terminal and Continental Intercalaire, of Cretaceous-Tertiary age, which occur in two major sedimentary basins: the Chad Basin, which extends across much of the east of Niger, and the Iullemeden Basin, which covers much of the west of the country. In some areas, these aquifers are overlain by, and in hydraulic continuity with, thick and often extensive unconsolidated Quaternary aquifers, including the extensive Chad Formation in the Chad Basin.  
 
The most extensive and productive aquifers of Niger are sedimentary formations known as the Continental Terminal and Continental Intercalaire, of Cretaceous-Tertiary age, which occur in two major sedimentary basins: the Chad Basin, which extends across much of the east of Niger, and the Iullemeden Basin, which covers much of the west of the country. In some areas, these aquifers are overlain by, and in hydraulic continuity with, thick and often extensive unconsolidated Quaternary aquifers, including the extensive Chad Formation in the Chad Basin.  
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====Unconsolidated Sedimentary====
 
====Unconsolidated Sedimentary====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||Aquifer Productivity||Description||Water quality  
+
|Named Aquifers||Period||Description||Water quality  
 
|-
 
|-
 
|Valley alluvial sediments; local aeolian deposits
 
|Valley alluvial sediments; local aeolian deposits
||Variable: often Moderate to High; sometimes Low
+
||Quaternary
 
||Where thick enough and dominated by sand and/or gravel, can be highly permeable with high storage potential. Alluvial deposits in valleys typically have shallow water tables and can form productive local aquifers. Small, local aeolian sand deposits on plateaus can be dry.  
 
||Where thick enough and dominated by sand and/or gravel, can be highly permeable with high storage potential. Alluvial deposits in valleys typically have shallow water tables and can form productive local aquifers. Small, local aeolian sand deposits on plateaus can be dry.  
 
||  
 
||  
 
|-
 
|-
 
|Chad Formation in the Chad Basin
 
|Chad Formation in the Chad Basin
||Variable: Moderate to High; sometimes Low
+
||Quaternary
 
||A heterogeneous aquifer of unconsolidated or loosely consolidated, interbedded sandy and clayey layers. Groundwater storage and flow occur preferentially in sandy layers. Individual sandy layers can be confined by overlying clayey layers, forming a multilayered aquifer that can be artesian in some cases.   
 
||A heterogeneous aquifer of unconsolidated or loosely consolidated, interbedded sandy and clayey layers. Groundwater storage and flow occur preferentially in sandy layers. Individual sandy layers can be confined by overlying clayey layers, forming a multilayered aquifer that can be artesian in some cases.   
  
A study in the Komadugu Yobe aquifer estimated the porosity of the Chad Formation, to between 50 and 100 m depth, at between 20 and 28%, and estimated a range of transmissivity values from 160 to 575 m<sup>2</sup>/day, with a mean transmissivity of 260 m<sup>2</sup>/day (Descloitres et al. 2013). Other transmissivity values obtained from test pumping in the Chad Formation are 3 m<sup>2</sup>/day, 100 m<sup>2</sup>/day and 250 m<sup>2</sup>/day (Descloitres et al. 2013), varying depending on whether the tested part of the aquifer was dominated by aeolian sand or by alluvial, often clayey sand.
+
A study in the Komadugu Yobe aquifer estimated the porosity of the Chad Formation aquifer, to between ~50 and 100 m depth, at between 20 and 28%, and estimated a range of transmissivity values from 160 to 575 m<sup>2</sup>/day, with a mean transmissivity of 260 m<sup>2</sup>/day (Descloitres et al. 2013). Other transmissivity values quoted from test pumping in the Chad Formation are 3, 100 and 250 m<sup>2</sup>/day (Descloitres et al. 2013), varying depending on whether the tested part of the aquifer was dominated by aeolian sand or by alluvial, often clayey sand.
  
 
Recharge is low, estimated as only a few millimetres per year (e.g. Leduc et al. 2000). Residence times for groundwater in the aquifer have been calculated at 1000 to 2000 years (Leduc et al 2000). Recharge occurs both directly from intermittent rains, and indirectly via leakage from rivers and, close to Lake Chad, sometimes also from the lake. Where the upper layers are dominated by sands, recharge is largely unrestricted, and so these layers are vulnerable to pollution. Recharge to deeper sandy layers can be restricted by overlying clayey layers, which also provide some protection from pollution.  
 
Recharge is low, estimated as only a few millimetres per year (e.g. Leduc et al. 2000). Residence times for groundwater in the aquifer have been calculated at 1000 to 2000 years (Leduc et al 2000). Recharge occurs both directly from intermittent rains, and indirectly via leakage from rivers and, close to Lake Chad, sometimes also from the lake. Where the upper layers are dominated by sands, recharge is largely unrestricted, and so these layers are vulnerable to pollution. Recharge to deeper sandy layers can be restricted by overlying clayey layers, which also provide some protection from pollution.  
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|}
 
|}
  
====Sedimentary - Intergranular Flow====
+
====Consolidated Sedimentary - Intergranular Flow====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||Aquifer Productivity||Description||Water quality  
+
|Named Aquifers||Period||Description||Water quality  
 
|-
 
|-
|Chad Basin Tertiary-Cretaceous (including Continental Terminal)
+
|Chad Basin (Continental Terminal, Cretaceous-Tertiary undifferentiated)
||Moderate to High
+
||Tertiary
 
||Overall, dominated by sandstones with significant permeability, but some areas dominated by low permeability siltstones and clays. Where clays are interbedded with sandstones, it forms a multilayered aquifer, sometimes artesian.
 
||Overall, dominated by sandstones with significant permeability, but some areas dominated by low permeability siltstones and clays. Where clays are interbedded with sandstones, it forms a multilayered aquifer, sometimes artesian.
  
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||  
 
||  
 
|-
 
|-
|Iullemeden (Niger) Basin Tertiary-Cretaceous (largely Continental Terminal; at depth may also include aquifers known as Continental Intercalaire)
+
|Iullemeden (Niger) Basin (largely Continental Terminal; at depth may also include aquifers known as Continental Intercalaire)
||Moderate to High
+
||Cretaceous-Tertiary
 
||Sandstones, often coarse grained, and clays, limestones and silts. The Continental Terminal aquifer extends across the Iullemeden Basin and is up to 450 m thick in its central part. It either overlies Continental Intercalaire rocks or directly overlies Precambrian basement. Andrews et al (1994) describe aquifer rocks of the older Continental Intercalaire in the northern part of the Iullemeden Basin. The Continental Terminal often forms a multi-layered aquifer, with thick sandstone (often fine-grained and/or silty) units forming aquifer layers, interspersed by lower permeability clayey, silty layers which often range from a few metres to around 20 m thick.  
 
||Sandstones, often coarse grained, and clays, limestones and silts. The Continental Terminal aquifer extends across the Iullemeden Basin and is up to 450 m thick in its central part. It either overlies Continental Intercalaire rocks or directly overlies Precambrian basement. Andrews et al (1994) describe aquifer rocks of the older Continental Intercalaire in the northern part of the Iullemeden Basin. The Continental Terminal often forms a multi-layered aquifer, with thick sandstone (often fine-grained and/or silty) units forming aquifer layers, interspersed by lower permeability clayey, silty layers which often range from a few metres to around 20 m thick.  
  
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==== Sedimentary - Intergranular & Fracture Flow====
 
==== Sedimentary - Intergranular & Fracture Flow====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||Aquifer Productivity||Description||Water quality  
+
|Named Aquifers||Period||Description||Water quality  
 
|-
 
|-
 
|Palaeozoic-Mesozoic sedimentary (including rocks known as the Continental Intercalaire)
 
|Palaeozoic-Mesozoic sedimentary (including rocks known as the Continental Intercalaire)
||Moderate to High
+
||Ordovician - Jurassic
 
||Shallower, younger sandstones tend to show more intergranular flow; older, deeper sandstones and limestones tend to be dominated by fracture flow. Aquifers can be very deep - e.g. an Ordovician aquifer at more than 800 m deep.  
 
||Shallower, younger sandstones tend to show more intergranular flow; older, deeper sandstones and limestones tend to be dominated by fracture flow. Aquifers can be very deep - e.g. an Ordovician aquifer at more than 800 m deep.  
  
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====Igneous====
 
====Igneous====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||Aquifer Productivity||Description  
+
|Named Aquifers||Period||Description  
 
|-
 
|-
 
|Igneous
 
|Igneous
||Probably Low to Moderate
+
||Quaternary - Mesozoic
 
||Little is known of the aquifer properties of the igneous rocks in Niger. They are likely to form similarly low productivity, local aquifers as the Precambrian basement, although the detailed pattern of fracturing and weathering may be different. The youngest, Quaternary, volcanic rocks may be more fractured and have higher permeability and better groundwater potential.   
 
||Little is known of the aquifer properties of the igneous rocks in Niger. They are likely to form similarly low productivity, local aquifers as the Precambrian basement, although the detailed pattern of fracturing and weathering may be different. The youngest, Quaternary, volcanic rocks may be more fractured and have higher permeability and better groundwater potential.   
 
|}
 
|}
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====Basement====
 
====Basement====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||Aquifer Productivity||Description||Water quality  
+
|Named Aquifers||Period||Description||Water quality  
 
|-
 
|-
|Precambrian Basement
+
|Basement
||Low
+
||Precambrian
 
||Discontinuous, low productivity aquifers controlled by the thickness and nature of weathering (regolith) and the presence of deeper fractures. Where weathered products are dominated by argillaceous material, yields are particularly low. Weathered Precambrian basement aquifers play an important role in the supply of water to some rural centres, particularly in Liptako and Damagaram-Mounio.
 
||Discontinuous, low productivity aquifers controlled by the thickness and nature of weathering (regolith) and the presence of deeper fractures. Where weathered products are dominated by argillaceous material, yields are particularly low. Weathered Precambrian basement aquifers play an important role in the supply of water to some rural centres, particularly in Liptako and Damagaram-Mounio.
 
||  
 
||  
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The Iullemeden aquifer system (SAI), shared by Mali, Niger and Nigeria, includes two major sedimentary aquifers: the Continental Intercalaire and the Continental Terminal. It covers an area of ​​approximately 500 000 sq km, and is the main source of sustainable water for the vast majority of the populations of this region. The Sahel and Sahara Observatory (OSS) initiated and implemented the SAI project between Niger, Mali and Nigeria, and set up joint a consultation structure in 2008.
 
The Iullemeden aquifer system (SAI), shared by Mali, Niger and Nigeria, includes two major sedimentary aquifers: the Continental Intercalaire and the Continental Terminal. It covers an area of ​​approximately 500 000 sq km, and is the main source of sustainable water for the vast majority of the populations of this region. The Sahel and Sahara Observatory (OSS) initiated and implemented the SAI project between Niger, Mali and Nigeria, and set up joint a consultation structure in 2008.
  
For more information about transboundary aquifers generally, please see the [[Transboundary aquifers | Transboundary aquifers resources page]].
+
For further information about transboundary aquifers, please see the [[Transboundary aquifers | Transboundary aquifers resources page]].
  
 
==References==
 
==References==
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Chippaux JP, Houssier S, Gross P, Bouvier C and Brissaud F. 2002. [https://www.ncbi.nlm.nih.gov/pubmed/12145956 Pollution of the groundwater in the city of Niamey, Niger]. Bull Soc Pathol Exot. 95(2), 119-23.
 
Chippaux JP, Houssier S, Gross P, Bouvier C and Brissaud F. 2002. [https://www.ncbi.nlm.nih.gov/pubmed/12145956 Pollution of the groundwater in the city of Niamey, Niger]. Bull Soc Pathol Exot. 95(2), 119-23.
  
Descloitres M, Chalikakis K, Legchenkoa A, Moussa, Genthon P, Favreau G, Le Coz M, Boucher M et Oï M. 2013. [https://doi.org/10.1016/j.jafrearsci.2013.07.006 Investigation of groundwater resources in the Komadugu Yobe Valley (Lake Chad Basin, Niger) using MRS and TDEM methods]. Journal of African Earth Sciences 87, 71-85.  
+
Descloitres M, Chalikakis K, Legchenkoa A, Moussa, Genthon P, Favreaud G, Le Coz M, Boucher M et Oï M. 2013. [https://doi.org/10.1016/j.jafrearsci.2013.07.006 Investigation of groundwater resources in the Komadugu Yobe Valley (Lake Chad Basin, Niger) using MRS and TDEM methods]. Journal of African Earth Sciences 87, 71-85.  
  
 
Favreau G, Leduc C, Seidel JL, Ousmane SD and Mariotti ANDRÉ. 2003. [http://hydrologie.org/redbooks/a278/iahs_278_163.pdf  Land clearance and nitrate-rich groundwater in a Sahelian aquifer, Niger]. International Association of Hydrological Sciences 278, 163-167.  
 
Favreau G, Leduc C, Seidel JL, Ousmane SD and Mariotti ANDRÉ. 2003. [http://hydrologie.org/redbooks/a278/iahs_278_163.pdf  Land clearance and nitrate-rich groundwater in a Sahelian aquifer, Niger]. International Association of Hydrological Sciences 278, 163-167.  
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Zaïri R. 2008. Etude géochimique et hydrodynamique de la nappe libre du bassin du lac Tchad dans les régions de Diffa (Niger oriental) et du Bornou (nord-est du Nigéria). PhD Thesis, Université Montpellier II, Montpellier, France, 225pp
 
Zaïri R. 2008. Etude géochimique et hydrodynamique de la nappe libre du bassin du lac Tchad dans les régions de Diffa (Niger oriental) et du Bornou (nord-est du Nigéria). PhD Thesis, Université Montpellier II, Montpellier, France, 225pp
  
Return to the index pages
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==Return to the index pages==
[[Africa Groundwater Atlas Home | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]]  
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[[Africa Groundwater Atlas Home | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]] >> Hydrogeology of Niger
  
  

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