Hydrogeology of Angola

Africa Groundwater Atlas >> Hydrogeology by country >> Hydrogeology of Angola

Most of the textual information on this page was taken from the chapter on Angola in the report ‘Groundwater in Eastern, Central and Southern Africa’ (UN 1989).This information is outdated. If you have more recent information on the hydrogeology of Angola, please get in touch.

Compilers

Dr Kirsty Upton and Brighid Ó Dochartaigh, British Geological Survey, UK

Geographical Setting

Map of Angola (For more information on the datasets used in the map see the geography resources section)

General

Angola is in central-southern Africa. There is a lowland coastal strip between 35 and 180 km wide that ranges from 300 to 500 m in elevation. Away from this, most of the country is formed of high plateaus from abotu 1000 to 1,800 m in elevation, with the highest point at 2,620 m. Hills and mountains rise inland from the coast into a major escarpment. Extending eastwards and southeastwards from the escarment is is a large area of high plateau (planalto).

Estimated Population in 2013*	21,471,618
Rural Population (% of total) (2013)*	57.5%
Total Surface Area*	1,246,700 sq km
Agricultural Land (% of total area) (2012)*	47.5%
Capital City	Luanda
Region	Central Africa
Border Countries	Namibia, the Democratic Republic of the Congo, Zambia
Annual Freshwater Withdrawal (2013)*	708.8 Million cubic metres
Annual Freshwater Withdrawal for Agriculture (2013)*	20.8%
Annual Freshwater Withdrawal for Domestic Use (2013)*	45.3%
Annual Freshwater Withdrawal for Industry (2013)*	33.9%
Rural Population with Access to Improved Water Source (2012)*	34.3%
Urban Population with Access to Improved Water Source (2012)*	67.6%

* Source: World Bank

Climate

Most of Angola has a dry season from May to October and a rainy season from February to April, with transitional rains from November to January. The south of the country, and along parts of the coastal strip, are semi-arid, with less than 400 mm/year of rain. The far north sees rainfall throughout much of the year, with more than 1,400 mm/year of rain. The climate is greatly influenced by prevailing winds from the west and southwest.

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  Koppen Geiger Climate Zones

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  Average Annual Precipitation

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  Average Temperature

For further detail on the climate datasets used see the climate resources section.

Surface water

The centre and north of Angola have many perennial rivers. In the south there are only three perennial rivers: the Cunene, Kuando and Cubango (which flows to the Okavango) rivers. The Zambezi River and several tributaries of the Congo River have their sources in Angola. Many rivers originate in the central uplands, but take quite different flowpaths. Some flow more or less due westerly to the Atlantic, providing water for irrigation and the potential for hydroelectric power in the dry coastal strip. Two of the largest rivers, the Cuanza and the Cunene, take a more indirect route to the Atlantic, the Cuanza flowing north and the Cunene flowing south before turning west. navigable. The Kwango and other rivers flow north from the high plateau to join the Kasai River (one of the largest tributaries of the Congo). Some rivers flow south into the Zambezi River system and from there to the Indian Ocean; others to the Okavango River (called the Cubango River in Angola) and thence to the Okavango Swamp in Botswana.

Surface Water Map of Angola (For more information on the datasets used in the map see the surface water resources section)

Soil

Soil Map of Angola (For map key and more information on the datasets used in the map see the soil resources section)

Land cover

In the far south and southwest of Angola, land cover is dominated by desert or sparse savannah or grassland vegetation. This gives way northwards to shrubland and then to a mix of shrubland then to deciduous forest, which covers much of the rest of the country.

Land Cover Map of Angola (For map key and more information on the datasets used in the map see the land cover resources section)

Geology

This section provides a summary of the geology of Angola. More information is available in the report‘Groundwater in Eastern, Central and Southern Africa’ (UN 1989) (see References section, below).

The geology map shows a simplified version of the geology at a national scale (see the Geology resources page for more details).

Geological Environments

Key formations	Period	Lithology
Unconsolidated/Semi-consolidated
Alluvium	Quaternary	Unconsolidated alluvial sediments infilling valleys.
Tertiary-Quaternary	Kalahari sequence	Loosely consolidated sandstones and unconsolidated sands and silts, covering much of the eastern part of the country.
Coastal basin
Cenozoic sedimentary rocks	Cretaceous-Tertiary	Up to 150 m thickness of Aptian-Maastrichtian age sedimentary rocks overlain by up to 1,200 m thickness of Palaeocene to Pliocene age sedimentary rocks.
Mesozoic sedimentary rocks
Karoo Supergroup	Permian-Jurassic	Argillaceous limestones, sandstones and shales at the edge of Congo basin. Up to 500 m thick. Intruded by dolerites.
Precambrian
Bembé system	Late Precambrian-Lower Cambrian	Schist-limestone series overlain by meta-sandstones, meta-conglomerates and quartzites
Oendolongo system	Precambrian	Quartzitic meta-sandstones
Craton / Crystalline Basement	Archaean	Crystalline igneous and metamorphic rocks, largely a granitogneissic complex.

Hydrogeology

This section provides a summary of the hydrogeology of the main aquifers in Angola. More information is available in the report‘Groundwater in Eastern, Central and Southern Africa’ (UN 1989) (see References section, below).

The hydrogeology map shows a simplified version of the type and productivity of the main aquifers at a national scale (see the Aquifer properties resource page for more details).

Unconsolidated

Named Aquifers	Period	General Description	Water quality

Sedimentary - Intergranular Flow

Named Aquifers	Period	General Description	Water quality

Sedimentary - Intergranular & Fracture Flow

Named Aquifers	Period	General Description	Water quality

Sedimentary - Fracture Flow

Named Aquifers	Period	General Description	Water quality

Basement

Named Aquifers	Period	General Description	Water quality

Groundwater use and management

Transboundary aquifers

For further information about transboundary aquifers, please see the Transboundary aquifers resources page

References

The following references provide more information on the geology and hydrogeology of Angola.

These, and others, can be accessed through the Africa Groundwater Literature Archive

United Nations. 1989. Groundwater in Eastern, Central and Southern Africa: Angola. United Nations Department of Technical Cooperation for Development, Natural Resources/Water Series No.19, ST/TCD/6.

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Africa Groundwater Atlas >> Hydrogeology by country >> Hydrogeology of Angola