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[[Africa Groundwater Atlas Home | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]] >> Hydrogeology of Ghana
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[[Overview of Africa Groundwater Atlas | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]] >> Hydrogeology of Ghana
 
 
[[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]]]
 
 
 
Farmers are known to be living in the area of present day Ghana were farmers by the 5th century BC, and by the 9th century AD the then Ghana Empire was a major power, and included parts of modern Senegal, Mauritania and Mali. After the 10th century, the empire came under Almovarid rule, and was later incorporated into Sahelian empires such as the Mali Empire. From the 16th century much of the area was brought under the governance of the Ashanti Empire. Many European powers contested the area for trading rights from the 15th century, and modern-day Ghana fell under British colonial rule from the late 19th century. After Ghana gained independence in 1957, the country saw a series of alternating military and civilian governments, and was often affected by economic instability. Since 1992, when multi-party system politics was restored, Ghana has enjoyed relative political stability, and has seen growing economic prosperity.
 
 
 
Ghana is a middle income country, with services accounting for around half of GDP, followed by manufacturing, extractive industries (including oil, discovered offshore in 2007; and gold, diamonds and a wide range of precious and industrial minerals). Agriculture is also important, particularly cocoa, of which Ghana is one of the world’s largest producers.
 
 
 
Ghana has major surface water resources in Lake Volta and its tributary rivers, but away from these groundwater is a key resource, particularly in dry seasons and in the drier north. Overall some 40% of households depend on groundwater, and this rises to 60% in rural areas. In the drier north, urban areas also depend primarily on groundwater. Rural areas, particularly in the north of the country, still lag behind in water supply infrastructure.
 
 
 
  
 
==Authors==
 
==Authors==
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'''Dr Kirsty Upton''', '''Brighid Ó Dochartaigh''', British Geological Survey, UK
 
'''Dr Kirsty Upton''', '''Brighid Ó Dochartaigh''', British Geological Survey, UK
 
'''Dr Imogen Bellwood-Howard''', Institute for Development Studies, UK
 
 
Please cite this page as: Obuobie, Agyekum, Appiah-Adjei, Upton, Ó Dochartaigh and Bellwood-Howard, 2018.
 
 
Bibliographic reference: Obuobie, E., Agyekum, W., Appiah-Adjei, E.K., Upton, K., Ó Dochartaigh, B.É. and Bellwood-Howard, I. 2018. Africa Groundwater Atlas: Hydrogeology of Ghana. British Geological Survey. Accessed [date you accessed the information]. http://earthwise.bgs.ac.uk/index.php/Hydrogeology_of_Ghana
 
 
 
==Terms and conditions==
 
 
The Africa Groundwater Atlas is hosted by the British Geological Survey (BGS) and includes information from third party sources. Your use of information provided by this website is at your own risk. If reproducing diagrams that include third party information, please cite both the Africa Groundwater Atlas and the third party sources. Please see the [[Africa Groundwater Atlas Terms of Use | Terms of use]] for more information.
 
  
 
==Geographical Setting==
 
==Geographical Setting==
  
[[File:Ghana_Political.png | right | frame | Ghana. Map developed from USGS GTOPOPO30; GADM global administrative areas; and UN Revision of World Urbanization Prospects. For more information on the map development and datasets see the [[Geography | geography resource page]]]]  
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[[File:Ghana_Political.png | right | frame | Political Map of Ghana (For more information on the datasets used in the map see the [[Geography | geography resources section]])]]  
  
 
===General===
 
===General===
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{| class = "wikitable"
 
{| class = "wikitable"
 
|-
 
|-
|Capital city || Accra
+
|Estimated Population in 2013* || 25,904,598
 
|-
 
|-
|Region || West Africa
+
|Rural Population (% of total)* || 47%
 
|-
 
|-
|Border countries || Cote d’Ivoire, Burkina Faso, Togo
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|Total Surface Area* || 227,540 sq km
 
|-
 
|-
|Total surface area* || 238,540 km<sup>2</sup>  (23,854,000 ha)
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|Agricultural Land (% of total area)* || 69%
 
|-
 
|-
|Total population (2015)* || 27,410,000
+
|Capital City || Accra
 
|-
 
|-
|Rural population (2015)* || 12,827,000 (47%)
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|Region || West Africa
 
|-
 
|-
|Urban population (2015)* || 14,583,000 (53%)
+
|Border Countries || Cote d’Ivoire, Burkina Faso, Togo
 
|-
 
|-
|UN Human Development Index (HDI) [highest = 1] (2014)*|| 0.5791
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|Annual Freshwater Withdrawal (2013)* || 982 Million cubic metres
 +
|-
 +
|Annual Freshwater Withdrawal for Agriculture* || 66%
 +
|-
 +
|Annual Freshwater Withdrawal for Domestic Use* || 24%
 +
|-
 +
|Annual Freshwater Withdrawal for Industry* || 10%
 +
|-
 +
|Rural Population with Access to Improved Water Source* || 81%
 +
|-
 +
|Urban Population with Access to Improved Water Source* || 93%
 
|}
 
|}
<nowiki>*</nowiki> Source: [http://www.fao.org/nr/water/aquastat/data/query/index.html?lang=en FAO Aquastat]
+
 
 +
<nowiki>*</nowiki> Source: World Bank
 +
 
  
 
===Climate===
 
===Climate===
  
 
The majority of Ghana is classified as a tropical savannah climate, apart from the south western corner which is designated tropical monsoon. Average annual precipitation is higher in the tropical monsoon region and generally decreases from south to north across the tropical savannah region. Average temperatures are slightly lower in the southwest of Ghana and increase towards the north.  
 
The majority of Ghana is classified as a tropical savannah climate, apart from the south western corner which is designated tropical monsoon. Average annual precipitation is higher in the tropical monsoon region and generally decreases from south to north across the tropical savannah region. Average temperatures are slightly lower in the southwest of Ghana and increase towards the north.  
 +
 +
<gallery widths="375px" heights=365px mode=nolines>
 +
File:Ghana_ClimateZones.png |Koppen Geiger Climate Zones
 +
File:Ghana_ClimatePrecip.png |Average Annual Precipitation
 +
File:Ghana_ClimateTemp.png |Average Temperature
 +
</gallery>
  
 
Precipitation varies throughout the year and is generally higher between April and October. In the south of the country this is more distinctly split into two wet seasons during April-June and September-October. Temperatures are generally highest in March and lowest in August.  
 
Precipitation varies throughout the year and is generally higher between April and October. In the south of the country this is more distinctly split into two wet seasons during April-June and September-October. Temperatures are generally highest in March and lowest in August.  
 +
 +
Rainfall time-series and graphs of monthly average rainfall and temperature for each individual climate zone can be found on the [[Climate of Ghana | Ghana Climate Page]].
  
[[File:Ghana_ClimateZones.png | 375x365px |Koppen Geiger Climate Zones]][[File:Ghana_ClimatePrecip.png | 375x365px |Average Annual Precipitation]][[File:Ghana_ClimateTemp.png | 375x365px |Average Temperature]]
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[[File:Ghana_pre_Monthly.png| 255x124px| Average monthly precipitation for Ghana showing minimum and maximum (light blue), 25th and 75th percentile (blue), and median (dark blue) rainfall]] [[File:Ghana_tmp_Monthly.png| 255x124px| Average monthly temperature for Ghana showing minimum and maximum (orange), 25th and 75th percentile (red), and median (black) temperature]] [[File:Ghana_pre_Qts.png | 255x124px | Quarterly precipitation over the period 1950-2012]] [[File:Ghana_pre_Mts.png|255x124px | Monthly precipitation (blue) over the period 2000-2012 compared with the long term monthly average (red)]]  
 +
  
[[File:Ghana_pre_Monthly.png| 255x124px| Average monthly precipitation for Ghana showing minimum and maximum (light blue), 25th and 75th percentile (blue), and median (dark blue) rainfall]] [[File:Ghana_tmp_Monthly.png| 255x124px| Average monthly temperature for Ghana showing minimum and maximum (orange), 25th and 75th percentile (red), and median (black) temperature]] [[File:Ghana_pre_Qts.png | 255x124px | Quarterly precipitation over the period 1950-2012]] [[File:Ghana_pre_Mts.png|255x124px | Monthly precipitation (blue) over the period 2000-2012 compared with the long term monthly average (red)]]
+
For further detail on the climate datasets used see the [[Climate | climate resources section]].
  
More information on average rainfall and temperature for each climate zone in Ghana can be found on the [[Climate of Ghana | Ghana Climate Page]]. 
 
 
These maps and graphs were developed from the CRU TS 3.21 dataset produced by the Climatic Research Unit at the University of East Anglia, UK. For more information see the [[Climate | climate resource page]].
 
  
 
===Surface water===
 
===Surface water===
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Some river flow data have been collected by research organisations working on individual projects. The German funded GLOWA Volta project, which ended in 2012, collected some river flow data that are currently held with the Volta Basin Authority (VBA) in Ouagadougou, Burkina Faso. The VBA has also been collecting river flow data through the VBA observatory, in collaboration with the Volta Basin riparian countries. Presently, the German funded West Africa Science Service Centre on Climate Change and Adapted Land Use (WASCAL) is recording river flow measurements at some locations in the Volta Basin, and has installed a number of automatic water level /discharge readers at selected points on the White Volta River and its major tributaries. The data are held by WASCAL at its offices in Ghana and Burkina Faso.
 
Some river flow data have been collected by research organisations working on individual projects. The German funded GLOWA Volta project, which ended in 2012, collected some river flow data that are currently held with the Volta Basin Authority (VBA) in Ouagadougou, Burkina Faso. The VBA has also been collecting river flow data through the VBA observatory, in collaboration with the Volta Basin riparian countries. Presently, the German funded West Africa Science Service Centre on Climate Change and Adapted Land Use (WASCAL) is recording river flow measurements at some locations in the Volta Basin, and has installed a number of automatic water level /discharge readers at selected points on the White Volta River and its major tributaries. The data are held by WASCAL at its offices in Ghana and Burkina Faso.
  
| [[File:Ghana_Hydrology.png | frame | Major surface water features of Ghana. Map developed from World Wildlife Fund HydroSHEDS; Digital Chart of the World drainage; and FAO Inland Water Bodies. For more information on the map development and datasets see the[[Surface water | surface water resource page]]]]
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| [[File:Ghana_Hydrology.png | frame | Surface Water Map of Ghana (For more information on the datasets used in the map see the [[Surface water | surface water resources section]])]]
 
|}
 
|}
  
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{|
 
{|
 
|-
 
|-
| [[File:Ghana_soil.png | frame | Soil Map of Ghana, from the European Commission Joint Research Centre: European Soil Portal. For more information on the map see the [[Soil | soil resource page]]]]
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| [[File:Ghana_soil.png | frame | Soil Map of Ghana (For more information on the datasets used in the map see the [[Soil | soil resources section]])]]
  
 
|The southwest of Ghana is dominated by Alisols. These highly acidic soils are typical of hot and wet climates and often form due to the weathering of minerals with a high aluminium content. This area corresponds with the dense forest belt in southwest Ghana.
 
|The southwest of Ghana is dominated by Alisols. These highly acidic soils are typical of hot and wet climates and often form due to the weathering of minerals with a high aluminium content. This area corresponds with the dense forest belt in southwest Ghana.
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|
 
|
  
| [[File:Ghana_LandCover.png | frame | Land Cover Map of Ghana,, from the European Space Agency GlobCover 2.3, 2009. For more information on the map see the [[Land cover | land cover resource page]]]]
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| [[File:Ghana_LandCover.png | frame | Land Cover Map of Ghana (For more information on the datasets used in the map see the [[Land cover | land cover resources section]])]]
|}
 
 
 
 
 
===Water statistics===
 
 
 
{| class = "wikitable"
 
| || 2000 ||2010||2013||2014||2015
 
|-
 
|Rural population with access to safe drinking water (%) || || ||  || || 84
 
|-
 
|Urban population with access to safe drinking water (%) || || ||  || || 92.6
 
|-
 
|Population affected by water related disease || No data || No data || No data || No data || No data
 
|-
 
|Total internal renewable water resources (cubic metres/inhabitant/year) || || ||  || 1105||
 
|-
 
|Total exploitable water resources (Million cubic metres/year) || No data || No data || No data || No data || No data
 
|-
 
|Freshwater withdrawal as % of total renewable water resources ||1.747 || || || ||
 
|-
 
|Total renewable groundwater (Million cubic metres/year) ||  || || ||26,300 ||
 
|-
 
|Exploitable: Regular renewable groundwater (Million cubic metres/year) || No data || No data || No data || No data || No data
 
|-
 
|Groundwater produced internally (Million cubic metres/year) || || ||  ||26,300 ||
 
|-
 
|Fresh groundwater withdrawal (primary and secondary) (Million cubic metres/year) || No data || No data || No data || No data || No data
 
|-
 
|Groundwater: entering the country (total) (Million cubic metres/year) || || ||  || ||
 
|-
 
|Groundwater: leaving the country to other countries (total) (Million cubic metres/year) || || ||  || ||
 
|-
 
|Industrial water withdrawal (all water sources) (Million cubic metres/year) ||950 || || || ||
 
|-
 
| Municipal water withdrawal (all water sources) (Million cubic metres/year)  || || ||251 || ||
 
|-
 
|Agricultural water withdrawal (all water sources) (Million cubic metres/year) ||652 || || || ||
 
|-
 
|Irrigation water withdrawal (all water sources) (Million cubic metres/year) || No data || No data || No data || No data || No data
 
|-
 
|Irrigation water requirement (all water sources) (Million cubic metres/year) || || 162||  || ||
 
|-
 
|Area of permanent crops (ha) || || ||  ||2,700,000 ||
 
|-
 
|Cultivated land (arable and permanent crops) (ha) || || ||  ||7,400,000 ||
 
|-
 
|Total area of country cultivated (%) || || ||  || 31.02||
 
|-
 
|Area equipped for irrigation by groundwater (ha) || No data || No data || No data || No data || No data
 
|-
 
|Area equipped for irrigation by mixed surface water and groundwater (ha) || No data || No data || No data || No data || No data
 
 
|}
 
|}
 
Source and more statistics at: [http://www.fao.org/nr/water/aquastat/data/query/index.html?lang=en FAO Aquastat].
 
  
 
==Geology==
 
==Geology==
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This section provides a summary of the geology of Ghana. More detail can be found in the references listed at the bottom of this page. Many of these references can be accessed through the [http://www.bgs.ac.uk/africagroundwateratlas/index.cfm Africa Groundwater Literature Archive].
 
This section provides a summary of the geology of Ghana. More detail can be found in the references listed at the bottom of this page. Many of these references can be accessed through the [http://www.bgs.ac.uk/africagroundwateratlas/index.cfm Africa Groundwater Literature Archive].
  
The geology map on this page shows a simplified version of the geology at a national scale (see the [[Geology | geology resource page]] for more details).
+
The geology map on this page shows a simplified version of the geology at a national scale (se see [[Geology | the Geology resources page]] for more details). The map is available to download as a shapefile (.shp) for use in GIS packages.  
 
 
[https://www.bgs.ac.uk/africagroundwateratlas/downloadGIS.html '''Download a GIS shapefile of the Ghana geology and hydrogeology map'''].
 
  
 
Other, larger scale, geological maps are available in printed format: see the Key Geology References section below for more details.
 
Other, larger scale, geological maps are available in printed format: see the Key Geology References section below for more details.
  
A regional project to update the geology map for the Volta and Keta basins, an area of approximately 100,000 km², included the production of a series of 48 new geological maps covering the area (Carney et al. 2010, Kalsbeek 2008).
+
[[ File:Ghana_Geology2.png | center | border | 500px]]
 
 
 
 
[[ File:Ghana_Geology3.png | center | thumb| 400px | Geology of Ghana at 1:5 million scale. Developed from USGS map (Persits et al. 2002). 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 Ghana geology and hydrogeology map].]]
 
 
   
 
   
  
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These rocks are overlain in valley areas by generally minor alluvium and other unconsolidated deposits of Quaternary age.  
 
These rocks are overlain in valley areas by generally minor alluvium and other unconsolidated deposits of Quaternary age.  
  
The following section provides a summary of the geology of Ghana based on these lithostratigraphic divisions. Sub-divisions of the major lithostratigraphic units are shown in the table below, although they are not distinguished on the map on this page.  
+
The following section provides a summary of the geology of Ghana based on these lithostratigraphic divisions. Sub-divisions of the major lithostratigraphic units are shown in the table below, although they are not distinguished on the map on this page. ''Many of these references can be accessed through the [http://www.bgs.ac.uk/africagroundwateratlas/index.cfm Africa Groundwater Literature Archive].''
 +
 
  
  
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==Hydrogeology==
 
==Hydrogeology==
  
This section provides a summary of the hydrogeology of the main aquifers in Ghana, on the lithostratigraphic divisions described in the Geology section. The hydrogeology of some of the sub-divisions of the major units is summarised, although the units are not distinguished on the map on this page.  More information is available in the references listed at the bottom of this page.
+
''This section provides a summary of the hydrogeology of the main aquifers in Ghana, on the lithostratigraphic divisions described in the Geology section. The hydrogeology of some of the sub-divisions of the major units is summarised, although the units are not distinguished on the map on this page.  More information is available in the references listed at the bottom of this page. ''Many of these references can be accessed through the [http://www.bgs.ac.uk/africagroundwateratlas/index.cfm Africa Groundwater Literature Archive].''
 
 
The hydrogeology map on this page shows a simplified version 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 Ghana geology and hydrogeology map'''].
+
The hydrogeology map on this page shows a simplified version of the type and productivity of the main aquifers at a national scale (see [[Aquifer properties| the Aquifer properties resource page]] for more details). ''The map is available to download as a shapefile (.shp) for use in GIS packages.'' Other hydrogeological maps at different scales and in different formats have been produced; some are listed in the key hydrogeology references section below.  
  
Other hydrogeological maps at different scales and in different formats have been produced; some are listed in the key hydrogeology references section below.
 
  
 
+
[[File:Ghana_Hydrogeology2.png | center | border | 500px]]
[[File:Ghana_Hydrogeology3.png | center | thumb| 400px| Hydrogeology of Ghana at 1:5million 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 Ghana geology and hydrogeology map].]]
 
  
  
 
====Consolidated Sedimentary Aquifers with Fracture Flow====
 
====Consolidated Sedimentary Aquifers with Fracture Flow====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||General Description||Water quality issues||
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|Named Aquifers||General Description||Water quantity issues||Water quality issues||Recharge
 
|-
 
|-
 
|Upper Voltaian: Obosum Group
 
|Upper Voltaian: Obosum Group
 
||Very low to zero intergranular permeability. Sandstone units can show variable development of joints, open planes and faults, creating secondary permeability. In thick sandstone units where secondary fracture permeability is well developed, high yielding boreholes have been developed, but in other areas, sandstones have proved to have low productivity. Mudstone and siltstone areas generally form a very low productivity aquifer, with little groundwater.  
 
||Very low to zero intergranular permeability. Sandstone units can show variable development of joints, open planes and faults, creating secondary permeability. In thick sandstone units where secondary fracture permeability is well developed, high yielding boreholes have been developed, but in other areas, sandstones have proved to have low productivity. Mudstone and siltstone areas generally form a very low productivity aquifer, with little groundwater.  
 +
||
 
||Groundwater from sandstones is often less mineralised than groundwater from mudstone and siltstones. However, there is some evidence that fluoride is more common in sandstones than in mudstones or siltstones. Groundwater from units dominated by mudstones and siltstones often has relatively high conductivity.
 
||Groundwater from sandstones is often less mineralised than groundwater from mudstone and siltstones. However, there is some evidence that fluoride is more common in sandstones than in mudstones or siltstones. Groundwater from units dominated by mudstones and siltstones often has relatively high conductivity.
 +
||
 
|-
 
|-
 
|Middle Voltaian: Oti/Pendjari Group
 
|Middle Voltaian: Oti/Pendjari Group
 
||Very low to zero intergranular permeability. Sandstone units show variably well-developed joints, open planes and faults, creating secondary permeability. Extensively fractured sandstone units can form moderately to highly productive aquifers, but there is wide variability in recorded yields, indicating that fractures are not well developed everywhere. Borehole yields range from less than 5 to 1000 l/min, but are often between 10 and 300 l/min. Units dominated by siltstones and mudstones tend to show lower yields, often between 20 and 40 l/min.  
 
||Very low to zero intergranular permeability. Sandstone units show variably well-developed joints, open planes and faults, creating secondary permeability. Extensively fractured sandstone units can form moderately to highly productive aquifers, but there is wide variability in recorded yields, indicating that fractures are not well developed everywhere. Borehole yields range from less than 5 to 1000 l/min, but are often between 10 and 300 l/min. Units dominated by siltstones and mudstones tend to show lower yields, often between 20 and 40 l/min.  
 +
||Water quantity issues
 
||Groundwater from sandstones is often less mineralised than groundwater from mudstone and siltstones. However, there is some evidence that fluoride is more common in sandstones than in mudstones or siltstones.
 
||Groundwater from sandstones is often less mineralised than groundwater from mudstone and siltstones. However, there is some evidence that fluoride is more common in sandstones than in mudstones or siltstones.
 +
||
 
|-
 
|-
 
|Lower Voltaian: Kwahu/Boumbaka groups
 
|Lower Voltaian: Kwahu/Boumbaka groups
 
||Very low to zero intergranular permeability. Sandstone units such as the Anyaboni Sandstone and Panaboko Sandstone formations often form moderately to highly productive aquifers, dominated by secondary fracture permeability, often in thin zones, with borehole yields often between 150 and 250 l/min. There is evidence for groundwater inflows to boreholes to at least 100m depth.  
 
||Very low to zero intergranular permeability. Sandstone units such as the Anyaboni Sandstone and Panaboko Sandstone formations often form moderately to highly productive aquifers, dominated by secondary fracture permeability, often in thin zones, with borehole yields often between 150 and 250 l/min. There is evidence for groundwater inflows to boreholes to at least 100m depth.  
 +
||
 
||Minor occurrences of saline groundwater have been noted in isolated boreholes, typically related to high sulphate concentrations. High iron is common, and high manganese in some areas. High fluoride concentrations occur rarely.  
 
||Minor occurrences of saline groundwater have been noted in isolated boreholes, typically related to high sulphate concentrations. High iron is common, and high manganese in some areas. High fluoride concentrations occur rarely.  
 +
||
 
|}
 
|}
 +
  
 
====Basement====
 
====Basement====
 
{| class = "wikitable"
 
{| class = "wikitable"
|Named Aquifers||General Description||Water quality issues||Recharge
+
|Named Aquifers||General Description||Water quantity issues||Water quality issues||Recharge
 
|-
 
|-
 
|Birimian, Granite, Dahomeyan, Togo and Buem Aquifers
 
|Birimian, Granite, Dahomeyan, Togo and Buem Aquifers
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The basement aquifers are generally confined and vary in thickness from 2-20 m, depending on the thickness of the weathered zone. Borehole depths vary between 40-200 m, depending on the type of aquifer.  
 
The basement aquifers are generally confined and vary in thickness from 2-20 m, depending on the thickness of the weathered zone. Borehole depths vary between 40-200 m, depending on the type of aquifer.  
  
 +
||
 
||Water quality in the basement aquifers is fair to good. Groundwater is typically slightly acidic (pH<6.5) with low salinity and total hardness, but slightly higher salinity occurs in some areas. High fluoride (up to 4 mg/l) occurs in some areas in the Upper Regions, as does iodine deficiency. High arsenic (>0.01 mg/l) has been seen in some parts of southwest Ghana, linked to the abundance of arsenic-bearing minerals associated with gold in mineralised veins.  
 
||Water quality in the basement aquifers is fair to good. Groundwater is typically slightly acidic (pH<6.5) with low salinity and total hardness, but slightly higher salinity occurs in some areas. High fluoride (up to 4 mg/l) occurs in some areas in the Upper Regions, as does iodine deficiency. High arsenic (>0.01 mg/l) has been seen in some parts of southwest Ghana, linked to the abundance of arsenic-bearing minerals associated with gold in mineralised veins.  
 
||Recharge occurs mainly from rainfall.  
 
||Recharge occurs mainly from rainfall.  
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===Groundwater Status===
 
===Groundwater Status===
 
+
Available data from past studies indicate that groundwater abstracted from boreholes in Ghana is generally of good chemical and microbiological quality and thus suitable for domestic (including drinking), agricultural and industrial uses. However, there are particular problems with the quality of groundwater in certain locations. These problems include:  
Available data from past studies indicate that groundwater abstracted from boreholes in Ghana is generally of good chemical and microbiological quality and thus suitable for domestic (including drinking), agricultural and industrial uses. However, there are particular problems with the quality of groundwater in certain places. These problems include:  
 
  
 
* low pH (3.5-6.0) waters, found mostly in the forest zones of southern Ghana;  
 
* low pH (3.5-6.0) waters, found mostly in the forest zones of southern Ghana;  
* high concentrations of iron in many places throughout the country;  
+
* high concentration of iron in many places throughout the country;  
* high natural concentrations of manganese and fluoride, mostly in the north, including the Upper East and Northern regions; and  
+
* high natural concentrations of manganese and fluoride, mostly in the north of the country; and  
* high levels of mineralisation, with total dissolved solids (TDS) in the range of 2000 up to more than 14,000 mg/l in some coastal aquifers, largely due to high salt (sodium chloride) from sea water intrusion (Kortatsi 1994).  
+
* high mineralisation with TDS in the range of 2000-14,584 mg/l in some coastal aquifers (Kortatsi 1994).  
  
Many of these groundwater quality problems are natural in origin. A key process is geochemical weathering of the bedrock under particular hydrogeological and hydrochemical conditions, which can lead to high fluoride, iron and manganese, among other elements. Local hydrogeological conditions can also cause naturally low pH levels. Others are caused or worsened by human activity. Sea water intrusion is often related to over-abstraction of groundwater in coastal aquifers. There are also some isolated reports of high groundwater nitrate concentrations, thought to be linked to the increasing use of artificial fertiliser by farmers, although there may also be a link between increased nitrate concentrations and local contamination by
+
These problems are generally attributed to geochemical weathering of the bedrock, anthropogenic activities, and to sea water intrusion in the case of high concentration of sodium chloride in coastal aquifers. There are also some isolated instances of high nitrate concentrations, thought to be linked to the increasing use of artificial fertiliser by farmers, although there may also be a link between increased nitrate concentrations and local contamination by
 
human and/or animal waste.
 
human and/or animal waste.
  
 
==Groundwater use and  management==
 
==Groundwater use and  management==
 
 
=== Groundwater use===
 
=== Groundwater use===
 
 
The main uses of groundwater in Ghana are (Obuobie & Barry 2012):
 
The main uses of groundwater in Ghana are (Obuobie & Barry 2012):
  
Line 360: Line 302:
  
 
=== Groundwater management===
 
=== Groundwater management===
 
 
The key institutions responsible for groundwater management in Ghana are:
 
The key institutions responsible for groundwater management in Ghana are:
  
Line 400: Line 341:
  
 
==References==
 
==References==
 
+
Many of the references below, and others relating to the hydrogeology of Ghana, can be found in the [http://www.bgs.ac.uk/africagroundwateratlas/searchResults.cfm?title_search=&author_search=&category_search=&country_search=GH&placeboolean=AND&singlecountry=1 Africa Groundwater Literature Archive].
Many of the references below, and others relating to the hydrogeology of Ghana, can be found in the [https://www.bgs.ac.uk/africaGroundwaterAtlas/atlas.cfc?method=listResults&title_search=&author_search=&category_search=&country_search=GH&placeboolean=AND&singlecountry=1 Africa Groundwater Literature Archive].
 
  
 
===Key Geology References===
 
===Key Geology References===
  
Geological Survey Department of Ghana. 2009. The Geological Map of Ghana (Scale 1: 1,000,000)
+
Geological Survey Department of Ghana. The Geological Map of Ghana (Scale 1: 1,000,000)
  
 
Bates DA. 1995. Geological Map of Ghana. Ghana Geological Survey, Accra, Ghana
 
Bates DA. 1995. Geological Map of Ghana. Ghana Geological Survey, Accra, Ghana
  
Carney JN, Jordan CJ, Thomas CW, Condon DJ, Kemp SJ and Duodo JA. 2010. [http://www.sciencedirect.com/science/article/pii/S0301926810002093 Lithostratigraphy, sedimentation and evolution of the Volta Basin in Ghana]. Precambrian Research, Vol.183, Issue 4, pp 701-724
+
Kesse GO. 1985. The Mineral and Rock Resources of Ghana. I–XIV, 1–610; Balkema, Rotterdam.  
  
 
Dickson KB and Benneh G. 1980. A new Geography of Ghana. Metricated Edition, Pearson Education Limited, Harlow, UK.
 
Dickson KB and Benneh G. 1980. A new Geography of Ghana. Metricated Edition, Pearson Education Limited, Harlow, UK.
 
Kalsbeek F (Ed). 2008. [http://www.geus.dk/program-areas/common/voltaian_workshop_report.pdf The Voltaian Basin, Ghana: Workshop and Excursion, March 10-17, 2009].
 
 
Kesse GO. 1985. The Mineral and Rock Resources of Ghana. I–XIV, 1–610; Balkema, Rotterdam.
 
  
 
Key RM. 1992. An introduction to the crystalline basement of Africa.  In: The hydrogeology of crystalline basement aquifers in Africa, EP Wright, WG Burgess. Geological Society Special Publication 66: 29-57.
 
Key RM. 1992. An introduction to the crystalline basement of Africa.  In: The hydrogeology of crystalline basement aquifers in Africa, EP Wright, WG Burgess. Geological Society Special Publication 66: 29-57.
Line 423: Line 359:
 
===Key Hydrogeology References===
 
===Key Hydrogeology References===
  
Agyekum WA and Dapaah-Siakwan S. 2008. The Occurrence of Groundwater in Northeastern Ghana. In: Adelana and MacDonald (eds), Applied Groundwater Studies in Africa: IAH Selected Papers on Hydrogeology 13.
+
Adelana SMA and MacDonald AM (Eds). 2008. Applied Groundwater Studies in AfricaIAH Selected Papers. British Geological Survey, Wallingford, UK. CRS Press, Taylor and Francis Press.  
 
 
Awuni JA and Akuriba MA. 2013. [http://www.tandfonline.com/doi/abs/10.1080/02508060.2013.819454 Small pumps and the poor: a field survey in the Upper East Region of Ghana]. Water International, 38:4, 449-464, DOI: 10.1080/02508060.2013.819454
 
 
 
Barry B, Kortatsi B, Forkuor G, Gumma M, Namara RE, Rebelo LM, vandenBerg J and Laube W. 2010. [https://www.bgs.ac.uk/africaGroundwaterAtlas/atlas.cfc?method=ViewDetails&id=AGLA600028 Shallow groundwater in the Atankwidi Catchment of the White Volta Basin: current status and future sustainability]. International Water Management Institute.  
 
  
 
British Geological Survey/WaterAid. [http://www.wateraid.org/~/media/Publications/groundwater-quality-information-ghana.pdf Groundwater Quality: Ghana]. Leaflet
 
British Geological Survey/WaterAid. [http://www.wateraid.org/~/media/Publications/groundwater-quality-information-ghana.pdf Groundwater Quality: Ghana]. Leaflet
 
Carrier MA, Lefebre R, Racicot J and Asare EB. 2008. [https://wedc-knowledge.lboro.ac.uk/resources/conference/33/Carrier_MA_GHA.pdf Northern Ghana Hydrogeological Assessment Project]. Paper presented at 33rd WEDC International Conferences, Accra, Ghana, 2008.
 
 
Carrier MA, Lefebre R and Asare E. 2011. [https://www.semanticscholar.org/paper/Hydrogeological-Assessment-Project-of-the-Northern-Carrier-Lefebvre/9399cfb2afc3f033c1c92ce4267a2509c41bf22c Hydrogeological Assessment Project of the Northern Regions of Ghana (HAP) : final technical report : Water Resources Database Development]. Project Report.
 
  
 
CSIR-Water Research Institute. 1996.  Hydrogeological Map of Ghana on Regional Basis.
 
CSIR-Water Research Institute. 1996.  Hydrogeological Map of Ghana on Regional Basis.
  
Dapaah-Siakwan S and Gyau-Boakye P. 2000.  Hydrogeologic Framework and borehole yields in Ghana.  Hydrogeology Journal 8, pp 405-416
+
Dapaah-Siakwan S and Gyau-Boakye P. 2000.  Hydrogeologic Framework and borehole yields in Ghana.  Hydrogeology Journal (2000), Vol. 8, pp 405-416
 
 
Evans AEV, Giordano M, Clayton T (Eds.). 2012. [https://ageconsearch.umn.edu/bitstream/137100/2/127.pdf  Investing in agricultural water management to benefit smallholder farmers in Ghana]. AgWater Solutions Project country
 
synthesis report. Colombo, Sri Lanka: International Water Management Institute (IWMI) 37p.
 
(IWMI Working Paper 147). Doi: 10.5337/2012.209
 
 
 
Forkuor G, Pavelic P, Asare E and Obuobie E. 2013. [http://www.tandfonline.com/doi/abs/10.1080/02626667.2012.754101 Modelling potential areas of groundwater development for agriculture in northern Ghana using GIS/RS]. Hydrological
 
Sciences Journal, 58:2, 437-451, DOI: 10.1080/02626667.2012.754101
 
  
 
Gill HE. 1969. A Groundwater Reconnaissance of the Republic of Ghana, with a Description of Geohydrologic Provinces, Geological Survey Water Supply Paper 1757-K, Washington, U.S.A
 
Gill HE. 1969. A Groundwater Reconnaissance of the Republic of Ghana, with a Description of Geohydrologic Provinces, Geological Survey Water Supply Paper 1757-K, Washington, U.S.A
  
Gyau-Boakye P and Dapaah-Siakwan S. 2000. Groundwater as Source of Rural Water Supply in Ghana, Journal of Applied Science and Technology, Vol. 5, Nos. 1 & 2, pp 77-86, 2000.
+
Gyau-Boakye P and Dapaah-Siakwan S. 2000. Groundwater as Source of Rural Water Supply in Ghana, Journal of Applied Science and Technology, Vol. 5, Nos. 1 & 2, pp77-86, 2000.
 
 
Gyau-Boakye P, Kankam-Yeboah K, Darko PK, Dapaah-Siakwan S, and Duah AA. 2008. Groundwater as a Vital Resource for Rural Development: An Example from Ghana. In: Adelana and MacDonald (eds), Applied Groundwater Studies in Africa: IAH Selected Papers on Hydrogeology 13.
 
 
 
Gumma MK and Pavelic P. 2013. [https://link.springer.com/article/10.1007%2Fs10661-012-2810-y  Mapping of groundwater potential zones across Ghana using remote sensing, geographic information systems, and spatial modelling]. Environmental Monitoring and Assessment, 185(4), 3561-3579.  
 
  
 
HAP (Hydrological Assessment Project of Northern Ghana). 2006. Hydrological assessment of the Northern Regions of Ghana: A bibliographical review of selected papers. CIDA, WRC, SNC-LAVALIN International.
 
HAP (Hydrological Assessment Project of Northern Ghana). 2006. Hydrological assessment of the Northern Regions of Ghana: A bibliographical review of selected papers. CIDA, WRC, SNC-LAVALIN International.
  
Kesse GO. 1985.  The Mineral and Rock Resources of Ghana.  A. A. Balkema/Rotterdam/Boston, 1985
+
Kesse G O. 1985.  The Mineral and Rock Resources of Ghana.  A. A. Balkema/Rotterdam/Boston, 1985
 
 
Martin N. 2006. [http://www.zef.de/fileadmin/template/Glowa/Downloads/thesis_martin.pdf Development of a water balance for the Atankwidi catchment, West Africa – a case study of groundwater recharge in a semi-arid climate]. Cuvillier Verlag Gottingen, Ecology and Development Series, No. 41, 168 pp.
 
 
 
Namara RE, Awuni JA, Barry B, Giordano M, Hope L, Owusu ES and Forkuor G. 2011. [https://cgspace.cgiar.org/handle/10568/16763 Smallholder shallow groundwater irrigation development in the upper east region of Ghana]. Vol. 143. IWMI.
 
 
 
Namara RE. 2012. [https://agriknowledge.org/downloads/jh343s338 Agricultural use of shallow groundwater in Ghana: A promising smallholders’ livelihood strategy]y. AgWater Solutions Project Case Study. IWMI
 
  
Namara RE, Hope L, Sarpong EO, De Fraiture C and Owusu D. 2013. [https://www.sciencedirect.com/science/article/pii/S0378377413002321 Adoption patterns and constraints pertaining to small-scale water lifting technologies in Ghana]. Agricultural Water Management, 131, 194-203.  
+
Martin N. 2006. Development of a water balance for the Atankwidi catchment, West Africa – a case study of groundwater recharge in a semi-arid climate, Ecology and Development Series, No. 41, Cuvillier Verlag Go¨ttingen, 168 pp.
  
Obuobie E and Barry B. 2010. [http://gw-africa.iwmi.org/Data/Sites/24/media/pdf/2008_agr_305_year_2_progress_report-narrative-final.pdf  Groundwater in sub-Saharan Africa: Implications for food security and livelihoods. Ghana Country Status on Groundwater]. Final report.
+
Obubie E and Barry B. 2012. Ghana. In P Pavelic, M Giordano, B Keraita, T Rao, and V Ramesh (Eds.), Groundwater availability and use in Sub-Saharan Africa: a review of 15 countries, Ch. 4, pp.43-64. Colombo, Sri Lanka: International Water Management Institute (IWMI), doi: 10.5337/2012.213
  
Obubie E and Barry B. 2012. Ghana. Chapter in P Pavelic, M Giordano, B Keraita, T Rao, and V Ramesh (Eds.), [https://www.bgs.ac.uk/africaGroundwaterAtlas/atlas.cfc?method=ViewDetails&id=AGLA600020 Groundwater availability and use in Sub-Saharan Africa: a review of 15 countries]; Ch. 4, pp.43-64. Colombo, Sri Lanka: International Water Management Institute (IWMI), doi: 10.5337/2012.213
+
Ó Dochartaigh BÉ, Davies J, Beamish D and MacDonald AM. 2011. [http://www.bgs.ac.uk/africagroundwateratlas/fulldetails.cfm?id=AGLA000028 UNICEF IWASH Project, Northern Region, Ghana: An Adapted Training Manual for Groundwater Development]. British Geological Survey Report OR/11/047.  
 
 
Obuobie E, Ofori D, Kwaku Agodzo S and Okrah C. 2013. [http://www.tandfonline.com/doi/abs/10.1080/02508060.2013.814212 Groundwater potential for dry-season irrigation in north-eastern Ghana]. Water International, 38:4, 433-448, DOI: 10.1080/02508060.2013.814212
 
 
 
Ó Dochartaigh BÉ, Davies J, Beamish D and MacDonald AM. 2011. [https://www.bgs.ac.uk/africaGroundwaterAtlas/atlas.cfc?method=ViewDetails&id=AGLA000028 UNICEF IWASH Project, Northern Region, Ghana: An Adapted Training Manual for Groundwater Development]. British Geological Survey Report OR/11/047.  
 
 
 
Regassa E, Namara LH, Owusu Sarpong E, De Fraiture C and Owusu D. 2012. [https://www.agriknowledge.org/downloads/c821gj80x Adoption of water lifting technologies for agricultural production in Ghana: implications for investments in smallholder irrigation system].  AgWater Solutions Project Case Study IWMI Ghana September 2012
 
  
 
Survey Department of Ghana. 1967. Hydrogeological Map of Ghana. An older version of this can be viewed online at [http://www.bgr.de/app/fishy/whymis/index.php?&type=country&id=GHA WHYMAP]
 
Survey Department of Ghana. 1967. Hydrogeological Map of Ghana. An older version of this can be viewed online at [http://www.bgr.de/app/fishy/whymis/index.php?&type=country&id=GHA WHYMAP]
 
Water Resources Commission. 2013. [http://www.wrc-gh.org/projects-and-programmes/hap-projects/ Hydrogeological Assessment of the Northern Region of Ghana Project (HAP)]. Webpage, Water Resources Commission, Ghana.
 
 
 
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[[Overview of Africa Groundwater Atlas | Africa Groundwater Atlas]] >> [[Hydrogeology by country | Hydrogeology by country]]
 
 
  
  
 
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