The Southern African Development Community (SADC)
The Southern African Development Community (SADC - Communauté Économique des États de
l'Afrique Centrale (CEEAC) in French) is an economic, social and cultural agreement to increase selfsufficiency and endogenous development, and create a framework for development and mobilisation
of human resources and material between fifteen southern African countries. The member states are
Angola, Botswana, the Democratic Republic of the Congo, Lesotho, Malawi, Madagascar, Mauritius,
Mozambique, Namibia, the Seychelles, South Africa, Swaziland, Tanzania, Zambia, and Zimbabwe. SADC
covers an area of 10 million km2 (around 32% of Africa) and has an estimated population of 240 million
(2010) with a density of around 30 people/km2 – however, this reflects a range of around 2 people/km2
in Namibia to over 600 people/km2 in Mauritius. There has been notable population growth in Malawi
and Mozambique. Per capita GDP is estimated at US$ 3 152 – with South Africa being the economic
powerhouse of the region [66]. The FAO has reported that agriculture supports about 85% of the rural
population and employs 80% of the labour force. Rural poverty, unsustainable development and land
tenure issues are the main causes and consequences of environmental degradation throughout the region.
The SADC area is bordered on three sides by the seas of the Atlantic and Indian Oceans, while the
north is characterised by tropical rainforest and savannah. Consequently, a broad range of soil types are
to be found. The western half of the region is dominated by the Kalahari and Namib Deserts. The arid
and hot conditions give rise to characteristic soil types. The Namib consists of sand seas (Arenosols)
near the coast with gravel plains and scattered mountain outcrops further inland (Leptosols). Some
of the sand dunes are 300 m high. Arenosols are interspersed by Leptosols and Cambisols. Unlike the
Namib, the Arenosols of the Kalahari support grasses, acacia trees and salt-tolerant vegetation. As in the
Sahara, low soil organic matter levels, low water retention, over-grazing and wind erosion are important
considerations in this area.
In the more temperate and more humid southern and eastern parts, a mosaic of leached, red Acrisols,
clay-rich Luvisols and stony Leptosols are mixed with Plinthosols, Vertisols and weakly developed
Cambisols and Regosols. In general, the soils of southern Africa are not characterised by high fertility
with water retention and availability being an issue (the fertile soils of the Western Cape river valleys and
on the KwaZulu-Natal coast are exceptions). High concentrations of salts give rise to saline and sodic
Solonchaks and Solonetz throughout Botswana, southern Mozambique, South Africa and Zimbabwe.
Lightly leached, clay-rich Luvisols,interspersed with Ferralsols and Leptosols, dominate Malawi, northern
Mozambique, southern Tanzania and eastern Zambia, with young Cambisols becoming more prevalent
in northern Tanzania. Along the Rift Valley, volcanic soils are common and are intensively cultivated. The
volcano of Kilimanjaro, the highest mountain in Africa, sits on the northern border of Tanzania.
Western Angola, DR Congo and much of Zambia are dominated by tropical Ferralsols under rainforest
(see page 75). While the region is home to the Congo and Limpopo river basins and several large lakes
(e.g. Lake Victoria - Africa’s largest lake by area and the largest tropical lake in the world), the huge delta
of the Limpopo is highlighted as a large expanse of Fluvisols.
The large expanse of Gleysols on the Angola/Zambia border denotes the Barotse wetlands in the
Zambezi floodplain. Almost due south in Botswana are the peatlands of the Okavango Delta.
Key issues affecting soils in the SADC region are restricted water-holding capacity, soil erosion and surface
crusting, large expanses of inherently saline, acid and/or nutrient poor soils and droughts in combination
with organic matter and nutrient depletion through unsustainable cultivation practices.
The large expanse of Gleysols in the centre of the
adjacent map denotes the swampy wetlands that are the
source of the Zambezi, one of Africa’s greatest rivers.
The image above was acquired by a sensor onboard
NASA’s Earth Observing-1 (EO-1) satellite and shows
a flood on the eastern tip of the Caprivi Strip in 2010.
This striking true-color image shows the stark boundary
between the southern and eastern edge of the floodplain
(which is higher land and dry) while to the north, the
land is flooded. Deep blue channels wind among green,
shallowly flooded plains. This area corresponds to the
zone of Fluvisols on the borders of the Caprivi Strip with
Botswana, Zambia and Zimbabwe. (NASA)
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Soil maps | Soil Atlas of Africa