Africa Geography
Africa, part of the “Old World”. The name comes from the Romans, who named the land around Carthage after the tribe of the Afri (singular: Afer) Africa who lived there; later the name was extended to the entire southern coast of the Mediterranean, and in the Age of Discovery to the entire continent. With a total area of around 30.3 million km 2, it covers a fifth of the land area of the earth (and is roughly three times the area of Europe). A good 1.2 billion people live in Africa (2016).
Surface shape
According to COUNTRYAAH, the relief of Africa is largely determined by wide-span hull areas and tabular lands, which rise on average over 1,000 m above sea level in the south and east. Half of the area is less than 500 m above sea level, but the actual low plains are rarely represented. The coasts are mostly steep coasts, especially in the north and south, in the tropics in parts with mangrove swamps and offshore coral reefs, otherwise flat and sandy with strong surf; wide deltas form the great rivers Nile, Niger and Zambezi.
Apart from the young Atlas Mountains, which geologically belong to the Alpidic system of Europe, Africa consists of an old base, which is divided into large basins by flat thresholds (Central Saharan, Upper Guinea, Lower Guinea, Asande and Lunda waves): basins without drainage in the wide table land the Sahara, in the Sudan zone the Niger, Chad and White Nile Basins, in Central Africa the huge Congo Basin, in the south the Kalahari Basin, which is surrounded in the southeast by an ancient mountain system, the Drakensberg. The East African rift system runs through the east of Africa, from the Red Sea to the Zambezi with Lake Tanganyika and Lake Malawi; it is accompanied by volcanoes, including the highest mountains in Africa (Kilimanjaro, Mount Kenya). The largest lake in Africa is Lake Victoria in the east; the largest lake without outflow is Lake Chad. The rivers of the winter rain areas (Atlas countries, South African Cape region) periodically carry water, in the deserts there are only episodic valleys (wadis, rivers). In basins without drainage, extensive salt pans (bulkheads, sebchas) form due to the high level of evaporation. In the tropical wetland, powerful currents developed that break through the edges of the basin with cataracts and waterfalls: Nile, Congo, Zambezi and Niger.
Climate
Due to its location on both sides of the equator, Africa shows the climatic zones in an almost symmetrical arrangement. The equatorial tropical zone with rain in all seasons has rainforest (Guinea Bay, northern Congo Basin). To the north and south there are zones with two rainy seasons during the highest position of the sun, separated by a short summer and a long winter dry season. Savannahs predominate here, initially moist savannah with evergreen trees and high grass corridors; towards the peripheral tropics (Sudan Zone, Zambezi Highlands) both rainy seasons combine to form a single one (in summer), which brings ever lower amounts of precipitation with increasing distance from the equator; Dry-, then thorn savannahs in the Sahel zone finally pass into the subtropical-marginal tropical arid regions of the Sahara and in the south into the Namib and Kalahari with only episodic precipitation. Parts of the East African highlands (Kenya, Tanganyika) and especially the Horn of Africa (Somali Peninsula) are arid areas in which tropical summer rains are largely absent or too low despite being close to the equator. The coastal areas of the Mediterranean, especially the Atlas countries, the Nile Delta and parts of the Cape Country, are dry and hot in summer under the influence of high pressure situations, but receive more rainfall in cool winter and moderately warm spring. The arid areas, which are among the hottest on earth, are in the central and eastern Sahara and on the Red Sea coast. The west coast is cooler than the east coast, along which the warm Agulhas current (in the south) runs, due to cold ocean currents (Canary Current in the north, Benguela Current in the south) and cold upwelling waters (therefore often foggy). In the interior, the higher the sea level, the warmth is softened by the nocturnal cooling and becomes more bearable as a result of the greater drought. Parts of the Ethiopian highlands and the highest mountain ranges reach into the cooler altitude zone with snowfall, which only occasionally reaches the lowlands on the extreme north and south edges of the continent; only the highest peaks, Kilimanjaro, Mount Kenya and Margherita Peak (formerly: Mount Stanley) in Ruwenzori, wear firn and glacier caps. On the whole, Africa is a dry part of the world; Water shortage is one of the biggest problems in many African countries. There is much evidence to suggest that it was at times more humid in the Pleistocene (see Prehistory section). By destroying the vegetation as a result of incorrect use (e.g. overgrazing), humans contribute to the devastation (Desertification) of large areas, especially in the desert fringes (Sahel). This regularly leads to famine, especially in the Sahel region.
