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'''This page has limited information. If you have more information on the hydrogeology of Liberia , please get in touch!'''  
 
'''This page has limited information. If you have more information on the hydrogeology of Liberia , please get in touch!'''  
  
[[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]]]
 
  
 
The Republic of Liberia began in its present form after 1822 as a settlement of the American Colonisation Society, who believed that Black Americans faced better chances there. The indigenous people inhabiting this area included the Kru and Grebo, many of whom had migrated from regions further east in past centuries. In 1847, the settlers declared Liberia an independent republic, with a constitution modelled on that of America, and retained its independence during the subsequent period of European colonialism. After the USA recognised Liberia in 1862, the two countries had reasonable diplomatic relations: Liberia supported the USA in WWII and the USA subsequently invested in Liberian infrastructure to a modest extent, albeit within the context of foreign direct investment in the rubber industry. There has been periodic ongoing tension between the minority of black settler-colonisers and indigenous peoples since the republic was founded. The settlers established and dominated the country’s political system. A period of serious unrest began in 1980 with a military coup, years of military rule and two civil wars that devastated the economy, ending with a peace agreement in 2003. Since then, Liberia has experienced relative political stability and economic recovery, but the economy and infrastructure remains poorly developed, and recovery was affected by an outbreak of Ebola virus in 2014-15.  
 
The Republic of Liberia began in its present form after 1822 as a settlement of the American Colonisation Society, who believed that Black Americans faced better chances there. The indigenous people inhabiting this area included the Kru and Grebo, many of whom had migrated from regions further east in past centuries. In 1847, the settlers declared Liberia an independent republic, with a constitution modelled on that of America, and retained its independence during the subsequent period of European colonialism. After the USA recognised Liberia in 1862, the two countries had reasonable diplomatic relations: Liberia supported the USA in WWII and the USA subsequently invested in Liberian infrastructure to a modest extent, albeit within the context of foreign direct investment in the rubber industry. There has been periodic ongoing tension between the minority of black settler-colonisers and indigenous peoples since the republic was founded. The settlers established and dominated the country’s political system. A period of serious unrest began in 1980 with a military coup, years of military rule and two civil wars that devastated the economy, ending with a peace agreement in 2003. Since then, Liberia has experienced relative political stability and economic recovery, but the economy and infrastructure remains poorly developed, and recovery was affected by an outbreak of Ebola virus in 2014-15.  
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[[File:Liberia_Hydrogeology.png | center | thumb| 400px | Hydrogeology of Liberia 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]].
 
[[File:Liberia_Hydrogeology.png | center | thumb| 400px | Hydrogeology of Liberia 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]].
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'''Summary'''
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There is relatively little information on hydrogeology and groundwater potential of the aquifers in Liberia.
  
 
====Unconsolidated====
 
====Unconsolidated====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Aquifer||Aquifer Productivity||Description
+
|Aquifer||Description
 
|-
 
|-
|Quaternary coastal and alluvial sediments
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|
||Generally Moderate to High Productivity (variable)
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||
||Where these sediments are dominated by coarse sand and gravel, and are suitably thick, they will form productive local aquifers. In other areas, if the sediments are dominated by fine grained sand and silt, or clay, they will have low permeability and storage and will form less productive aquifers. In the most productive areas, it is probable that sustainable borehole yields of between about 0.5 and 3 litres/second (l/s) would be possible, and possibly higher.
 
 
|}
 
|}
  
 
====Sedimentary - Mixed Intergranular and Fracture flow====
 
====Sedimentary - Mixed Intergranular and Fracture flow====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Aquifer||Aquifer Productivity||Description
+
|Aquifer||Description
 
|-
 
|-
 
|Laterite
 
|Laterite
||Low Productivity
 
 
||The laterite generally has low permeability (UN 1988).
 
||The laterite generally has low permeability (UN 1988).
 
|-
 
|-
 
|Cretaceous (occasionally Devonian)
 
|Cretaceous (occasionally Devonian)
||Low to Moderate Productivity
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||The coastal sandstones are likely to form low to moderate productivity aquifers, with relatively small stores of groundwater. In an investigation by the Liberia Water and Sewer Corporation (LWSC) for new urban water supplies, boreholes were drilled to 100 m in the sandstones, and many provided a sustainable yield of 5 m<sup>3</sup>/hour (1.4 litres/second or l/s) (UN 1988).  
||The coastal sandstones are likely to contain relatively small stores of groundwater. In an investigation by the Liberia Water and Sewer Corporation (LWSC) for new urban water supplies, boreholes were drilled to 100 m in the sandstones, and many provided a sustainable yield of 5 m<sup>3</sup>/hour (1.4 litres/second or l/s) (UN 1988).  
 
 
|}
 
|}
  
 
====Igneous====
 
====Igneous====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Aquifer||Aquifer Productivity||Description
+
|Aquifer||Description
 
|-
 
|-
 
|Mesozoic Igneous Intrusive rocks - Unknown aquifer potential
 
|Mesozoic Igneous Intrusive rocks - Unknown aquifer potential
||Unknown
 
 
||Very little is known of the aquifer characteristics of these rocks. They are likely to be crystalline with very low intergranular porosity and permeability, so that groundwater potential will depend largely on the degree and type of  weathering and/or fracturing in the rocks. Groundwater is likely to be present mainly in the uppermost few tens of metres. Overall aquifer productivity is likely to be low.
 
||Very little is known of the aquifer characteristics of these rocks. They are likely to be crystalline with very low intergranular porosity and permeability, so that groundwater potential will depend largely on the degree and type of  weathering and/or fracturing in the rocks. Groundwater is likely to be present mainly in the uppermost few tens of metres. Overall aquifer productivity is likely to be low.
 
|}
 
|}
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====Basement====
 
====Basement====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Aquifer||Aquifer Productivity||Description
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|Aquifer||Description
 
|-
 
|-
|Precambrian
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|Precambrian - Low to Moderate Productivity
||Low to Moderate Productivity
 
 
||Groundwater in basement aquifers is found only in shallow weathered zones, and below this in fractures in the rock. Aquifer productivity and groundwater potential depend on the extensiveness of weathering and fracturing. Some information from aquifer tests is given in UN (1988): six boreholes in Buchanan town, between 80 and 100 m deep, gave specific capacity values of 0.25 to 2.60 m<sup>3</sup>/hour/m; and two boreholes in Zwedru town gave specific capacity values of 7.60 m<sup>3</sup>/hour/m (63 m deep) and 24.5 m<sup>3</sup>/hour/m (44 m deep). The higher yields are likely to be in areas with better developed weathering and fracturing, and may also be related to high recharge from abundant rainfall (UN 1988).   
 
||Groundwater in basement aquifers is found only in shallow weathered zones, and below this in fractures in the rock. Aquifer productivity and groundwater potential depend on the extensiveness of weathering and fracturing. Some information from aquifer tests is given in UN (1988): six boreholes in Buchanan town, between 80 and 100 m deep, gave specific capacity values of 0.25 to 2.60 m<sup>3</sup>/hour/m; and two boreholes in Zwedru town gave specific capacity values of 7.60 m<sup>3</sup>/hour/m (63 m deep) and 24.5 m<sup>3</sup>/hour/m (44 m deep). The higher yields are likely to be in areas with better developed weathering and fracturing, and may also be related to high recharge from abundant rainfall (UN 1988).   
  
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|}
 
|}
  
==Groundwater use and management==
 
 
===Groundwater use===
 
 
In 1988, the UN reported that groundwater was used to supply five towns via urban distribution networks, three of which abstracted groundwater from 150 m deep boreholes and the other two from large diameter wells. Groundwater was also widely used in rural areas and small towns, usually from hand dug wells equipped with traditional equipment or modern hand pumps, and in some cases also from drilled boreholes. Many hand dug wells are dug into the laterite surface formations (UN 1988). Maintenance of handpumps was reported as a key problem in rural areas, often leading to abandonment of boreholes and wells (UN 1988).
 
 
In 1988 the UN reported that two mining companies use groundwater for their industrial use, but that very little groundwater was used in agriculture, mainly because of abundant rainfall. Groundwater was used to a limited extent in the dry season for nursery irrigation of commercial crops (e.g. oil palm, coffee and cocoa) (UN 1988).
 
  
===Groundwater management===
+
==Groundwater management==
  
 
Water point databases exist with information on more than 3,000 hand dug wells and more than 600 boreholes in Liberia, although information for some parts of the country is not yet recorded. Most of this information was collated during the 2011 [http://wash-liberia.org/data-maps/ Liberian Waterpoint mapping project]. Most of the waterpoints recorded are groundwater sources - hand dug wells or boreholes, although only protected (improved) hand dug wells are recorded  in the database. The waterpoint database does not contain much groundwater information: no geological log information is available for the groundwater sources, and most have no information on groundwater (rest/static) level. Some qualitative water quality information is available. The waterpoint database is available to view and download at the [http://wash-liberia.org/data-maps/ WASH Liberia] website.  
 
Water point databases exist with information on more than 3,000 hand dug wells and more than 600 boreholes in Liberia, although information for some parts of the country is not yet recorded. Most of this information was collated during the 2011 [http://wash-liberia.org/data-maps/ Liberian Waterpoint mapping project]. Most of the waterpoints recorded are groundwater sources - hand dug wells or boreholes, although only protected (improved) hand dug wells are recorded  in the database. The waterpoint database does not contain much groundwater information: no geological log information is available for the groundwater sources, and most have no information on groundwater (rest/static) level. Some qualitative water quality information is available. The waterpoint database is available to view and download at the [http://wash-liberia.org/data-maps/ WASH Liberia] website.  

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