Contour and topography
Wallace G. Mills Hist. 316 1 Geography
Contour and topography
- this diagram gives an indication of what most of Africa (fromSouth Africa through central Africa to north Africa—westAfrica is a bit of an exception which we shall look at in a minute)might look like in a cross-section. There are relatively narrowcoastal plains, often only 100-300 miles wide; then there aresteep escarpments leading to a rather high central plateau.
- this topography has had a number of very important historicalramifications; it sharply inhibited penetration of much of Africaby outsiders. It prevented navigation very far inland becauselarge rivers were disrupted by large, sometimes spectacular fallsand rapids (Stanley Falls on the Congo River and Victoria Fallson the Zambesi River).
- the coastal plains have been rife with diseases harmful to people (especially those who have not built up immunity during childhood) and draft animals (malaria & sleeping sickness especially). The result is that people in the interior of Africa were not subjected to invasion by whites for a long time after Africa began to be circumnavigated by the Portuguese late in the 15th C, not until the second half of the 19th C.
- as a result, it was not until late in the 19th C that technological and medical advances made it possible for Europeans to penetrate into the interior of Africa and to carry out conquest.
- the great height of the plateau has also tended to moderatethe temperatures, and provide a temperate climate, even in areasathwart the equator. This is true even of Uganda and the highlandsarea of Kenya even though the equator passes through them. Hereare some comparisons with North America, including the Canadianprairies:
- the temperate highland areas in South Africa, in Zimbabwe (formerly called Rhodesia) and in Kenya attracted substantial numbers of white settlers in the 19th and 20th Cs.
- as noted earlier, west Africa is a partial exception in thatelevations are less and the gradients are much more gradual. Asa result, the Niger River is navigable for very substantial distancesas is its major tributary, the Benue River. However, althoughthe Niger River was known to Europeans for a long time throughIslamic sources and travelers from the Mediterranean area, themouth of the Niger R. was unknown to Europeans until the early19th C. There were a couple of reasons for this: one early sourceincorrectly stated that the Niger flowed from east to west andsearchers kept looking much farther west for the mouth; the actualmouth of the Niger is in a maze of lagoons and small rivuletswhich were known as the Oil Rivers. The mystery was not clearedup until Mungo Park made his famous journey overland to the Nigerand down it in 1805-6. He died before reaching the mouth. Theactual mouth was not known for certain until 1830.
- however, even this discovery did not have much practical advantageas navigation by sail was limited and real navigation requiredsteamships. Even more significantly, the disease barrier had tobe overcome. This was proven very vividly by the Niger Expeditionof 1841. Although the prophylactic benefits of quinine againstmalaria had been discovered, the discovery was not known or itsvalidity was not accepted by many doctors. The expedition failedbecause of severe losses of life. However, using quinine, anotherexpedition in 1854 was successful and finally opened this areaof west Africa to penetration by Europeans.
- South Africa is also an exception. The Cape Province area ofSouth Africa is free of the diseases which provided such a barrierfarther north; the southern reach of malaria ends in Natal andthe north east corner of the Transvaal and the tsetse fly doesnot extend down into South Africa. This enabled the establishmentof a settlement of whites at Cape Town; people and animals spreadeastwards over what became the Cape Colony. As well, the gradientsfrom the south in the Cape Colony into the high veld interiorare more gradual. This allowed land-hungry, Afrikaans-speakingmigrants (known as Trekboers) to penetrate into the high veldinterior of the Orange Free State and the Transvaal in the 1830s& 40s in a series of migrations known as the Great Trek
Rainfall and Vegetation
- rainfall is a crucial element; lack of rain has producedthe largest desert area in the world, the Sahara. The Kalahariand Namibian deserts in southern Africa are also large.
- additional large areas of land are dry to semi-dry as a resultof limited rainfall (see rainfall map).Other areas have very heavy rainfall; this variation in rainfallgives rise to very different types and patterns of vegetation.We shall look at the different types from dry to wet. (See
- of course, the line between one type and another is not clearlydrawn as it is on the map representation as there is a shadingfrom one type to another and even within a type; e.g., withinsavanna, there is considerable variation in the amount of treesfrom dry areas where trees are rare and often isolated (exceptin river valleys) to higher rainfall areas where trees and shrubsmay be quite heavy.
- another factor should be noted; much of African soils are acidic.This means that organic materials tend to break down thus rapidlydepleting fiber from the soil under cultivation. Thus, productivitytends to drop off relatively quickly. (It also tends to make archeologya bit frustrating because most materials other than metal breakdown; even bones tend to disappear more quickly and completely.)
- traditionally, Africans solved this problem with shifting agriculture, often in what was called ‘slash and burn’. In this approach, each year some new land would be cleared for cultivation, often using fire; at the same time, land that had been under cultivation for several years and was losing its fertility (the time would vary from 5 years to perhaps 10-12) would be allowed to go fallow and reoccupied by natural vegetation. Only after 15-20 years would this land again be brought under cultivation.
- this approach meant that only a small portion of the total land was under cultivation at any one time. Thus, many whites who came late in the 19th C and after declared that this approach was ‘primitive’ and ‘inefficient’. However, techniques brought by whites, including ‘scientific’ ones, have not solved the problem very well either.
- this solution also meant that the population was relatively small as food supplies put an upper limit on population with the natural regulators—disease, pestilence and even war when provoked by drought, insects, etc.—restraining population.
- populations have increased dramatically during the colonial period and since independence while productivity of the land (especially since independence) has been static or even declining.
- even in coastal West Africa where high rainfall made more intensive agriculture possible, the land had to be allowed to revert to fallow periodically as a way to restore productivity. New monocultures (peanuts, cocoa etc.) as well as population pressures have reduced or eliminated this with serious effects.
Crop Distributions
- the accompanying maps show the distribution of some of themajor food crops in Africa.
- it should be noted that maize (corn as we call it or mealiesas it is known in South Africa) is relatively recent having beenintroduced by the Portuguese in the 15th and 16th Cs. However,it quickly became a staple in many areas of southern and centralAfrica. It produces more (although it depletes the soil more quicklyalso) and is less vulnerable to birds than the cereal staplesit replaced—millet and sorghum. Its introduction and spreadmay be a major explanation for the population explosion in Natalduring the late 18th and early 19th Cs which led to the creationof warring kingdoms out of which the Zulu Kingdom emerged withincredible consequences; millions of people died or had theirlives disrupted seriously not only in southern Africa but alsoup through central Africa all the way to southern Tanzania.
Mineralisation
- South Africa is certainly the most richly endowed area inAfrica in this regard—gold, coal, uranium, diamonds, platinum,manganese, iron, etc. etc.
- other areas are much less endowed, much less in most instancesthan many of the proponents of empire were predicting in the 19thC when they were urging the occupation and conquest of Africain what historians call the ‘scramble’.
- however, there are large copper deposits in central Africa (Zaireand Zambia), some coal in a few areas, uranium in Zaire, and bauxitein West Africa. Gold was mined in Zimbabwe but most of that wasmined out by the 18th C. West Africa provided substantial quantitiesof gold for hundreds of years going back to the time of the RomanEmpire; however, its recovery was done on a small scale over widelyscattered areas. It continues to be produced up to the presentbut only by traditional, small-scale methods; it rarely has beenpossible to exploit economically using large scale mining technology.However, there are some small Canadian gold mining companies activeor trying to start operations in Ghana especially. Diamonds aresaid to be fueling the terrible civil war in Sierra Leone.
- considerable amounts of oil have been found in Nigeria and Angola.
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