home international passport South Africa. Plains in Africa Desert on the South African plateau

South Africa. Plains in Africa Desert on the South African plateau

East Africa - a subcontinent located in the east of the mainland, unites two physiographic countries: the Ethiopian Highlands and the Somali Peninsula and the East African Highlands (plateau). The region is elongated in a submeridional direction (between 18° north and south latitude). It begins in the north at the southeastern margin of the Sahara, in the west it has fairly clear orographically determined boundaries with the regions of North and Central Africa, in the south it is separated by a system of faults from similar structures in South Africa, reaching the tectonic valley of the lower reaches of the river. Zambezi. In the east, the subcontinent faces the Indian Ocean and its seas.

The subcontinent is located in the most tectonically active part of the African Platform in the development zone of a grandiose complex system of continental rifts, which is unparalleled both in length and amplitude of vertical movements.

East African rift zones occupy a special place in shaping the nature of the region. They are associated with relief features, predominantly mountainous and flat-mountainous, the widespread development of volcanism, including modern, and increased seismicity. Rifts are expressed by grabens, the bottoms of which are often occupied by lakes.

The region is located in the zone of action of the equatorial monsoons of both hemispheres. Characteristic its climates - extreme differentiation of moistening conditions not only by seasons, but also within the territory. To a large extent, this depends on the fragmentation of the relief and configuration. coastline.

East Africa is distinguished by a large variety of soil and vegetation cover - from evergreen wet rainforest on the windward mountain slopes to the desert landscapes of the Afar depression.
Large areas are occupied by savannas of various types. Altitude zonality is expressed in the mountains.
East Africa is the main watershed of the mainland. From here the rivers of the basins originate indian ocean, mediterranean sea and the river system of the Congo, carrying to the Atlantic.
Animal world The subcontinent is very rich and diverse: all the main representatives of the fauna of the African savannas live here.
East Africa is an area of fairly dense settlement and long-standing agricultural land use.
The subcontinent has large reserves of minerals. In connection with human activities, the nature of the subcontinent has been significantly changed.
East Africa is regarded as the ancestral home of man. Perhaps it was here that the species Homo sapiens arose as a result of the evolution of ancient primates.

Ethiopian Highlands and Somali Plateau

This physiographic country includes the Ethiopian highlands, the Afar depression, the plateau and the coastal lowland of the Somali peninsula. In the west, the region borders on the White Nile basin, in the south - on the East African Highlands, in the north and east it goes to the Red Sea, the Gulf of Aden and directly to the Indian Ocean. Ethiopia, Somalia and Djibouti are located on its territory, in 1993 Eritrea separated from Ethiopia.

As a result of active tectonic movements, a very diverse and even contrasting relief was formed here. The main part of the region is occupied by the Ethiopian Highlands, which is a highly elevated block of the African Platform within the Eritrean anteclise (Nubian-Arabian arch), almost bounded by faults on all sides.

Height reaches 3000-4000 meters, highest point- Ras Dashan (4623 meters). The steep stepped slopes of the highlands make it difficult to access, which is why it is often called a bastion massif. Fissure eruptions of trachyte and basalt lavas occurred along the fault lines. Covers were formed, having in some places a thickness of up to 2000 meters. Stepped lava plateaus - ambas are typical for the relief of the highlands. Cut in all directions by deep erosive-tectonic valleys-canyons, the ambas look like flat-topped remnants with separate volcanoes. Some of them have been active in historical times. Faults define the lines of the coasts of the Red Sea and the Gulf of Aden, limit the subsidence zone - the Afar depression. Its bottom, covered with lavas, is a low plateau with isolated volcanic cones. Separate basins lie below sea level. Lake Assal is the lowest place on the African continent (-153 meters). The Ethiopian graben in the south separates the highlands from the plateau of the Somali Peninsula, they descend in steps to the southeast to the Indian Ocean. The lower step is a wide, low-lying coastal plain. The eastern margin of the peninsula is also bounded by a fault, along which the ocean floor subsided.

In general, the climate of the country is subequatorial, variable humid, but the fragmentation of the relief determines the diversity and contrast climatic conditions region. Local factors of climate formation play here no less a role than general regularities.

Precipitation is mainly associated with the summer equatorial monsoon of the southwest direction. Most of the moisture (1000 mm per year or more) is received by the windward southwestern and western slopes of the Ethiopian highlands. northern slopes are influenced by tropical air. They are dry. Most of the Somali peninsula receives little rainfall (250-500 mm per year). Even on the coast of the Indian Ocean, the climate is arid, as the flow of the southwest monsoon moves along the coastline here. The driest areas are the Ethiopian graben, the coasts of the Red Sea and the Gulf of Aden, and especially the Afar depression. The entire region, except for mountainous areas, is characterized by high air temperatures: average monthly temperatures are not lower than 20°C, maximum temperatures are up to 40-50°C. The Afar depression is one of the hottest places: the average January there is 24 ° C, the average July is 36 ° C. The Ethiopian highlands are much cooler. Altitude climatic zonality is traced here:

colla belt (hot) - up to a height of 1500-1800 meters; average monthly temperatures - 20°C and above, the amount of precipitation on the windward slopes - 1000-1500 mm per year;
war-degas belt (moderate) - up to a height of 2400-2500 meters; small seasonal temperature fluctuations: in December - not lower than 13°С, in April (the warmest month) - not higher than 16-18°С; precipitation - 1500-2000 mm per year;
degas belt (cold) - on high mountain ranges; average monthly temperatures do not exceed 16°C, in winter there are severe frosts, snow falls; however, there are no glaciers.

Thus, the region combines dry and hot climates of low plains, humid and cool climates of highlands and plateaus, humid and hot climates of the Kolla mountain belt and adjacent flat areas.

The river network is well developed in the Ethiopian highlands. Here originate one of the sources of the Nile - the Blue Nile, the right tributaries of the White Nile - Sobat and the Nile - Atbara, Omo. The Blue Nile carries twice as much water into the main river as the White Nile. Its runoff is regulated by Lake Tana. There are small lakes at the bottom of the Ethiopian graben. On the Somali Peninsula, the river network is poorly developed, most of the rivers dry up, and in the Afar depression there is practically no surface runoff, there are only a few small salt lakes. The river flows into one of them. Avash flowing down from the highlands.

The complex structure of the relief and the contrasts of climatic conditions determine the diversity of the vegetation cover of the Ethiopian-Somali region. In the Ethiopian Highlands, altitudinal zonation is exceptionally pronounced.

Dense evergreens grow on the damp western slopes in the colla belt and in deep valleys with good moisture. rainforests, which are close to equatorial in species composition and structure. The watershed plateaus are occupied by savannahs. Thickets of thorny bushes and xerophytic light forests dominate on dry leeward slopes. The War-Dega belt was once dominated by forests of cedars and yews, which have been largely cut down. The thickets of tree-like juniper and woodlands of deciduous trees - wild olive and fig tree - are better preserved. The main part of the belt is now occupied by a mountain savanna with candelabra-like spurges, umbrella acacias, giant sycamore trees and a rich grass cover of cereals. Coniferous forests of junipers, podocarpus, etc. grow in the lower part of the degas belt. Above, mountain meadows - grasslands with groves of the kusso tree and individual tree-like junipers predominate. Thickets of giant St. John's wort, tree-like heathers, and communities of xerophytic bush grasses appear even higher. The uppermost parts of the mountains are covered with rocky placers, which are covered with snow in winter. In the Afar depression and on the coasts of the Red Sea, the Gulf of Aden and the Indian Ocean, semi-desert and desert vegetation is developed. The interior plateaus of the Somali peninsula are dominated by landscapes of deserted savannahs.

The fauna is common for the savannas and tropical forests of Africa, including mountainous ones.

In the War-Dega belt, there are monkeys that cannot tolerate constant heat - hamadryas, Gverets, Geladas. The fauna of the region has a relatively high degree of preservation even outside protected areas. So, elephants live in the forests of the lower belt of mountains, and this is one of the few places where they do not live in reserves.

The Ethiopian highlands have significant agro-climatic and land resources. Its territory as a whole receives sufficient Agriculture the amount of precipitation. Particularly favorable conditions for the cultivation of valuable crops and for the life of people in the war-degas belt with its relatively cool, constantly humid climate and fertile dark red and chernozem-like soils.

Most of the Ethiopian population lives here. This is one of the ancient centers of agriculture. They grow cereals, tobacco, oilseeds, citrus fruits, and grapes. The name of the belt, translated from the language of local peoples, means "grape zone". This belt is considered the birthplace of the coffee tree. In the south and southwest, coffee plantations rise up to 2000 meters. Some cereals also come from here - durum wheat, rye, barley, etc. Only some flat valleys are waterlogged, swampy and unfavorable for life. In the Kolla belt with a hot, humid climate, the population is sparse, but in some places there are plantations of coffee, cotton, and sugar cane. Cattle breeding is developed in dry regions. Cattle breeding (zebu, sheep, goats) is also carried out by the inhabitants of the degas - the cold zone, and only in its lower part, up to a height of 2800 meters, they grow the local teff cereal. At the lower boundary of this belt at an altitude of 2440 m is the capital of Ethiopia - Addis Ababa.

The arid territories of the Somali peninsula are not very suitable for agriculture. The population is concentrated in the river valleys and oases, where commercial tropical crops are grown on irrigated lands: bananas, sugar cane, cotton, date palm, and for own consumption - cereals and legumes. Most of the population is engaged in cattle breeding. In many places in Afar, desert coasts, the interior of the Somali plateau, even in wells, the water is brackish. There is practically no settled population. In the arid regions of this region, well-preserved bone remains of animals have been found, including ancient primates, which are considered human ancestors.

Large reserves of ore minerals are concentrated in the bowels of the region. There is gold, platinum, ores of copper, nickel, manganese, iron, niobium, uranium and thorium. There are also deposits of piezoquartz, potassium and table salts, native sulfur, mica, and gypsum. But only a small part of this wealth is used.

The main problem in the region is the lack of water in many parts of it. There are severe droughts that cause famine. Drought in the 70s 20th century in Somalia led to a huge reduction in the number of livestock and the death of a large number of people. Drought control is one of the most acute problems in the region. Despite the fairly good preservation of the fauna, many species of animals have been severely exterminated and are even on the verge of extinction. For their protection, several national parks and reserves have been created in Ethiopia and reserves in Somalia. They protect not only animals, but also typical and interesting landscapes, for example, in the Awash Park, where there are manifestations of volcanic activity. Palm forests around hot springs and riverine gallery forests are subject to protection.

East African Highlands

Most of this physiographic country is located in the Southern Hemisphere. In the north, the East African Highlands borders on the Ethiopian along the faults in the area of Lake Rudolf, to the south it extends to the valley of the river. Zambezi. The western border with the Congo basin runs along the watershed between the rivers of the Congo basin and the African Great Lakes. In the east, the region faces the Indian Ocean. Within its boundaries are Kenya, Uganda, Rwanda, Burundi, Malawi, Tanzania and northern Mozambique. In many features of nature, this physiographic country is similar to the Ethiopian highlands. Tectonic mobility, fragmentation of the relief, manifestations of ancient and modern volcanism, a subequatorial climate with sharp internal differences, and a variety of landscapes dominated by savannah formations determine the similarity of these regions. The rift zones of the East African Highlands are genetically related to the Ethiopian graben, which, in fact, is their continuation to the north. However, the region has a number of natural features that distinguish it from the Ethiopian-Somali country.

With no less tectonic mobility than in the Ethiopian Highlands, the areas of lava covers are not so large in the East African Highlands. There are volcanic massifs, often of considerable height: Kilimanjaro (Kibo peak - 5895 meters, the highest point of the mainland), Kenya (5199 meters), Meru (4567 meters), Karisimbi (4507 meters), Elgon (4322 meters), etc. Among the large and there are many active small volcanoes.

The highlands are located within the anteclise of the ancient African platform with outcrops of crystalline rocks, in some places overlain by continental sediments and lava sheets. In the Cenozoic, the rising dome of the anteclise was broken by rift faults. There are three branches of continental rifts. The western rift runs along the entire western margin of the highlands. Within its limits, a system of grabens is formed - from the graben occupied by the valley of the river. Albert Nile, in the north, to the tectonic valley of the lower reaches of the river. Zambezi. Most of them are a chain of narrow, long and deep lake basins (the bottom of Lake Tanganyika lies more than 600 meters below sea level). Between them and along the sides of the grabens there are horst and arched uplifts with an average height of 1000-3000 meters. As a rule, active volcanoes are associated with them. Between lakes Albert and Eduard rises the Rwenzori massif ( moon mountains), reaching at its highest point - the peak of Margherita - 5109 meters. The entire area is highly seismic. The central rift begins in the north with the basin of Lake Rudolf and in the south in the basin of Lake Nyasa merges with the western branch. Here, a flat-bottomed valley (the Great Valley, or Rift Valley) with steep slopes (“rift shoulders”) was formed in the graben. At the bottom of it are many small salt lakes. Within this zone eruptions of lavas occurred, and then the central type was formed, which, including the highest massifs of the highlands, rise along tectonic fissures. Calderas are also characteristic of this zone, including the famous Ngorongoro Crater with a diameter of 22 km. The eastern fault zone descends in fault steps towards the Indian Ocean and defines the rectilinear outlines of the coastline. The spaces between the rift zones are dominated by a flat-mountainous relief, more or less leveled, with remnant mountains and uplands.

The subequatorial climate of the highlands has its own characteristics.

In the southern part, winds with an eastern component dominate throughout the year, since the northeastern winter monsoon of the Northern Hemisphere does not change direction when crossing the equator, dragging into the South African baric minimum. In the north, the southwest monsoon dominates in summer. Winter precipitation is orographic, so only the windward slopes of the mountains are irrigated. Humidification of different regions within the highlands is not the same. The highest amount of precipitation (up to 2000-3000 mm per year) is received by high mountain ranges. In the north-west and south-west of the country and on the mountainous coast south of 5 ° S. sh. falls 1000-1500 mm. In the rest of the highlands, the annual precipitation is 700-1000 mm, and in closed depressions and in the extreme northeast - no more than 500 mm. Due to the general high hypsometric level of the East African Highlands, in most of its territory, air temperatures are relatively low (monthly averages are not higher than 19-20 ° C). Only at low altitudes, mainly on the coast, they rise to 23-28°C. Annual amplitudes of average monthly temperatures are up to 5-6°C. There are frosts in the mountains above 2000 meters, snow falls at an altitude of 3500 meters, the highest peaks (Kilimanjaro, Kenya, Rwenzori) have ice caps.

The East African Highlands - the "roof of Africa" - is the highest region of the mainland and the main watershed of the basins of the Indian, Atlantic Oceans and the Mediterranean Sea. This is where the river starts. Nile, numerous tributaries of the river flow from here. Congo (Lualaba), r. Zambezi, a large number of rivers flowing into the Indian Ocean. The highlands are distinguished by one of the largest clusters of lakes on Earth. Great African lakes, occupying grabens in the Western Rift Zone, have an elongated shape and great depths (Tanganyika - up to 1435 meters). They are usually flowing and fresh. In a vast tectonic basin outside the rift zones lies the second largest freshwater reservoir in the world - Lake Victoria. Large masses of water in large lakes have a significant impact on local climates. There are many salt lakes on the bottoms of the grabens in the Central Rift - Natron, Nakuru, etc.

Most of the highlands are occupied by typical savannahs and light forests.

In the most arid northeastern regions, the same plant groups are common as on the Somali Peninsula (desert savannas). Drainage basins of salt lakes are surrounded by salt marshes with halophytic vegetation. In the western regions with a humid climate, the lower slopes of the mountains and the coasts of lakes were occupied by hylaea, which are now replaced in large areas by mixed forests with an admixture of deciduous species and tall grass savannahs. Altitude zonality is expressed in the mountains. Among the belts, the “belt of fogs” with mountain hylaea (2300-2500 meters) and the belt of mountain meadows with giant lobelia and tree-like crossworts stand out. The nival belt starts at a height of 4,800 meters.

Nowhere in the world is there such a variety of large animals, especially the inhabitants of the savannas.

Antelopes, buffaloes, zebras, giraffes and other herbivores once densely populated the highlands. They were hunted by large predators (lions, leopards, cheetahs, etc.). There were many elephants, rhinos, hippos, various monkeys. Prolonged extermination caused a strong decrease in the number of animals, some of the species are on the verge of extinction. Numerous National parks and reserves in which the number of animals is regulated. Among the world-famous parks are Virunga, Kagera, Mount Kenya, Kilimanjaro, Serengeti, Ngorongoro (a natural "aviary" bounded by the slopes of the caldera), Nakuru, where 370 species of birds live near the lake, including giant flamingo colonies. Mountain gorillas live in the southern protected part of the Kivu Park.

Scientific research is being carried out in protected areas. The countries of the region receive substantial income from foreign tourists who are attracted here by exotic fauna and flora, unusual landscapes, the possibility of sport hunting under licenses

In addition to land, agro-climatic and biological resources, the East African Highlands has unique reserves fresh water, concentrated in the African Great Lakes, which are used both for water supply, and as transport routes, and as a source of fish. The subsoil of the region is rich: there is gold, diamonds, various ores, salts are mined, including sodium carbonate - natron.

The region is densely populated, but unevenly populated. Most people live on the shores of fresh lakes. Maasai pastoralists roam the savannahs of Kenya and Tanzania. Almost all landscapes of the East African Highlands have undergone anthropogenic changes.

That is why mountain-building processes on the mainland are very poorly developed - young mountains grow only in the north of the continent.

More than 4/5 of Africa is occupied by plateaus. Lowlands on the mainland are virtually absent. Not only the mainland is located on the African-Arabian platform, but also Madagascar, Seychelles and the Arabian Peninsula.

The African Highlands are located in the southeastern part of the mainland. The average heights here exceed 1000 m above sea level. In this region, the African-Arabian platform rises somewhat.

The Ethiopian highlands are located in southeastern Africa. This part of the mainland is called High Africa, it is here that the highest peak of the continent, Mount Kilimanjaro, is located.

These areas are characterized frequent earthquakes, which provoke the eruptions of the volcanoes Karisimbi and Cameroon. Highlands are also found in the Sahara desert, the highest of them being the Tibesti and Ahaggar highlands.

Mountains of Africa

On the coast of the Indian Ocean are the Cape and Dragon Mountains - their height decreases towards the center of the mainland. The Cape Mountains formed during the Upper Paleozoic.

The region of the Cape Mountains is characterized by a Mediterranean type of climate. The Cape Mountains are a vivid example of the revived mountains that were formed on the ancient destroyed mountain systems and inherited from them the folded structure that can be traced in the modern relief.

The highest peak of the Cape Mountains is Mount Compasberg, whose height reaches 2500 m. In the north of the mainland, as a result of the displacement of the spirit of the lithospheric plates, young Atlas Mountains were formed.

These mountains are a continuation of the young mountains of Europe, which are located in the Gibraltar region. The length of the mountain ranges of the Atlas Mountains is 2500 km: they originate in the north of Morocco and stretch to Tunisia.

The highest peak of the Atlas Mountains is Mount Toubkal (4100m). Due to tectonic faults, earthquakes often occur in the Atlas Mountains region.

Lowlands of Africa

The lowlands of Africa occupy only 9% of its territory. The lowest point on the continent salt Lake Assal, which is located on the territory of the state of Djibouti (Red Sea coast). Lowlands are also common in some countries of Central Africa.

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Africa is part of the world. Geography of African countries

Mining regions of Africa

Over the past decades, Africa has become one of the largest producers of mineral raw materials.

Its share in the world mining industry is approximately 1/7, but in the production of diamonds, gold, cobalt, manganese ores, chromites, uranium concentrates, phosphorites, it is much larger. Much copper and iron ore, bauxite, oil and natural gas are also mined.

Let us add that Africa dominates the market of such "metals of the 20th century" as vanadium, lithium, beryllium, tantalum, niobium, and germanium. Almost all of the extracted raw materials and fuel are exported from Africa to economically developed countries, which makes its economy very dependent on the world market.

In particular, this applies to countries such as Algeria, Libya, Guinea, Zambia, Botswana, where the mining industry provides more than 9/10 of all exports.

For the development of the mining industry, Africa has very favorable natural preconditions.

Its minerals are genetically related, firstly, to the outcrops of the folded basement of the African Platform, secondly, to the sedimentary deposits of the cover of this platform, thirdly, to the areas of Paleozoic, Mesozoic and Cenozoic (Alpine) folding, fourthly, to the sedimentary deposits of foothill and intermountain troughs, fifthly, with lateritic weathering crusts, and, finally, sixthly, with intrusions of igneous rocks.

In this case, for example, deposits of iron and copper ores can occur both in the outcrops of the crystalline basement and in the cover of sedimentary deposits, and iron ore can also be found in the lateritic weathering crust.

It must also be borne in mind that the bowels of Africa have not yet been studied enough. In recent decades, prospecting and exploration activities have been expanded and have led to a significant increase in the reserves of most minerals.

But nevertheless, many, especially deep, horizons in this sense still remain "terra incognita", which opens up prospects for new great geological discoveries - just as it happened in the 1950s-1960s. with African oil.

In total, in Africa, one can distinguish seven major mining regions.

Three of them are in North Africa and four in sub-Saharan Africa (Figure 149).

Two of the North African mining regions predate World War II and have been further developed in recent decades.

This is the region of the Atlas Mountains, where rather large deposits of iron, manganese, and polymetallic ores are associated with mineralization processes that took place during the Hercynian folding period.

But the main wealth of this region is the world's largest phosphorite-bearing belt, stretching along the southern slopes of the Atlas through the territory of Morocco, Algeria and Tunisia. The thickness of the phosphorite suite here reaches 80-100 m, and the total reserves of phosphorites (in terms of P205) amount to 22 billion tons, of which 21 billion are in Morocco. In terms of phosphorite mining, this country is second only to the United States and China, and in terms of their export it ranks first in the world.

The second mining region of North Africa is located in Egypt. Here, deposits of oil and natural gas, iron, titanium and other ores, phosphorites, rock salt and other fossil raw materials are connected with the sedimentary cover of the Nubian-Arabian massif and with the rift basins of the Red Sea. .

Rice. 149.

Mining areas in Africa

But, of course, the main mining region of North Africa is the youngest of them, located within the Algerian and Libyan parts of the Sahara desert.

The territorial combination of mineral resources in it is much more limited and is actually represented only by oil and natural gas, but in terms of the size of their reserves, production and the overall role of the region in the world economy, it is far ahead.

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Physical and geographical characteristics of South Africa.

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High Africa. South Africa occupies a high part of the mainland south of the watershed plateau between the Congo and Zambezi river basins. The relief is dominated by plateaus and plateaus. The country is distinguished by a wide variety of landscapes due to the sharp contrasts in moisture and the relief of individual areas.

The main part is occupied by the South African Plateau, to which the Cape Mountains adjoin from the south. A special natural area forms the island of Madagascar.

South African plateau lies within the Precambrian African Platform, occupying the Kalahari and Karoo syneclises. The Precambrian basement in the Kalahari syneclise is shallow and in some places comes to the surface, forming ledges and uplifts; the sedimentary cover is represented by horizontal Upper Cretaceous and Cenozoic continental deposits, mainly sandstones and sands (Kalahari Formation).

The Karoo syneclise is a piedmont trough of the platform, which arose in connection with the formation of the Cape mountain system; within its limits, the crystalline basement is deeply lowered and hidden under a thick layer of Permian-Triassic lagoonal sediments, mainly sandstones and shales (Karru Formation); in some places these rocks are intruded by lavas.

The deposits of the Karoo Formation make up the southern and southeastern plateaus.

In terms of surface structure, the South African Plateau has much in common with the Congo Basin, but is located much higher. The central part of the plateau is occupied by plains kalahari basins, lying at an altitude of 900-1000 m; here, red and white sands are common on the surface, hilly into low dunes.

The Kalahari Basin is surrounded on all sides by marginal plateaus and uplands with numerous insular remnant massifs and mountains.

They gradually rise towards the outskirts up to 1200-2500 m and more. The greatest width of the plateau is reached in the east and south of the region.

To the east are the Matabele and Weld Plateaus, and to the south the Upper Karoo Plateau.

Matabele Plateau lies between the Zambezi and Limpopo rivers. The plateau is composed of crystalline rocks; its surface is slightly hilly, there are separate insular mountains. The marginal parts of the plateau are strongly dissected by river erosion and stand out sharply above the neighboring plains.

South of the Limpopo River is located Weld plateau. It is a series of stepped plateaus (High, Middle, Shrub, and Low Weld) descending towards the Kalahari Basin and the Limpopo River Valley.

The plateaus are composed of sandstones, shales and conglomerates of the karru formation, in places intrusive and volcanic rocks.

Upper Karoo, located south of the Orange River, closes the Kalahari Basin in the south, descending to it in several steps.

The plateau is composed of horizontally occurring sandstones and shales, penetrated by numerous intrusions, forming remnant elevations, sometimes sharp peaks.

In the west of the plateau, the strip of marginal plateaus narrows. Plateaus are composed of crystalline rocks and continental deposits. They are crowned with insular mountains and remnant massifs, reaching their highest height in the Comas Plateau, where dislocated slates and quartzites are exposed.

The ledge reaches its highest height in the east, in dragon mountains Oh. The southern part of the mountains - the Basuto Highlands, which has basalt lavas - is the highest massif of the Kalahari ring frame. Its peak Thabana-Ntlenyana (3482 m) is the highest in South Africa.

The marginal plateaus in the east are adjoined by a vast Mozambique lowlands.

It is composed of Cretaceous and Tertiary deposits and is broken up by tectonic fissures in the northern part. In the west, the plateaus of the marginal plateaus break off to the coastal plain. Its section between the rivers Kunene and Orange is the Namib Desert. The desert stretches from north to south for more than 1500 km, occupying a narrow strip of ancient crystalline peneplain, crushed by faults.

The plateau lies in the subequatorial, tropical and subtropical climatic zones.

However, tropical climate types predominate. In the summer of the Southern Hemisphere, a local baric depression forms over the Kalahari.

The north of the region (up to the middle reaches of the Zambezi) is irrigated by the summer equatorial monsoon. The entire eastern part is influenced by the southeast trade wind, which brings moist tropical air from the Indian Ocean, heated over the warm Mozambique Current.

Abundant precipitation falls on the Mozambique lowlands, the slopes of the Great Escarpment and the eastern marginal plateaus. To the west of the Great Ledge and the marginal plateaus, marine tropical air quickly transforms into continental air and the amount of precipitation decreases.

The west coast is under the influence of the South Atlantic High, which is intensified by the powerful cold Benguela Current. Atlantic air warms up over the surface of the mainland and emits almost no precipitation.

On the western marginal plateaus there is a front between the maritime Atlantic and continental tropical air; here the amount of precipitation increases slightly.

In the winter of the Southern Hemisphere, a local anticyclone forms over the plateau, merging with the South Atlantic and South Indian baric maxima. Downward currents of air determine the dry season; precipitation does not fall.

The South African Plateau is an area of relatively high temperatures, significant daily and annual fluctuations. But on the plateau temperatures are moderated by a considerable height. Over most of the plateau, summer temperatures are + 20- * + 25 ° C, not rising above + 40 ° C; winter temperatures are +10 - + 16°С.

On the Upper Karoo Plateau, frosts occur in winter, and snow falls on the Basuto Highlands.

Precipitation is brought here by the southeast summer trade wind (more than 1000 mm per year, and on the slopes of the Basuto highlands - over 2000 mm). The most frequent and heavy rains fall from November to April. On the eastern marginal plateaus, precipitation decreases on the Weld Plateau (750-500) and Matabele (750-1000 mm). The summer maximum precipitation is also preserved in the interior regions, but their annual amounts are decreasing.

On the central Kalahari plains, the rainy season is reduced to 5-6 months, the annual precipitation does not exceed 500 mm. To the southwest, the amount of precipitation decreases to 125 mm per year. The driest part of the region is the coastal Namib desert (less than 100 mm of precipitation per year). Little precipitation will fall on the western marginal plateaus (up to 300 mm per year).

The river network on the plateau is poorly developed.

Most of the channels of the Kalahari, the western and southern marginal plateaus do not have permanent watercourses. The largest river is the Zambezi.

The large rivers of the region - the Orange and the Limpopo collect their waters from the Matabele plateau and the High Weld. The Okovango River is the main internal water system of the Kalahari Basin. During rains, the Okovango basin sometimes overflows with water, its excess being directed from Okovango to the Zambezi and the Makarikari salt marsh.

Big sizes South African plateau, differences in relief and climate create a variety of landscapes.

Almost all landscapes of the mainland are represented in South Africa..

Along with zonal differences, there are also sectoral differences.

The eastern humid oceanic, mid-continental and western relatively cool desert oceanic sectors are well expressed in the region. In the eastern sector, where there is a lot of precipitation, zones of seasonally humid forests change from north to south: subequatorial (up to 20 ° S), tropical (20-30 ° S) and subtropical monsoon.

On the slopes of the Dragon Mountains, altitudinal zonality of the forest-meadow type is well expressed. Seasonally humid forests occupy the windward slopes up to a height of 800-1000 m. Above, shrub thickets and mountain-valley, mainly coniferous forests, meadows, and rocky placers appear; similar vegetation is characteristic of the Basuto Highlands (thickets of bushes, individual trees, meadows and stony placers).

In the middle continental sector (Kalahari Basin and marginal plateaus), natural areas savannahs, woodlands and shrubs of the subequatorial and tropical zones, tropical and subtropical semi-deserts, subtropical mountain steppes.

However, semi-desert landscapes dominate.

Lowlands, plains, plateaus

Rare vegetation consists of xerophytic herbs, shrubs and individual acacias, spurges, aloe. The Kalahari is characterized by wild watermelons, the stems of which cover large areas.

In the western oceanic sector is the tropical desert of Nami b. In its southern part, along the valleys of dry channels and in places where groundwater is shallow, rather dense vegetation of succulent shrubs and semi-shrubs, stunted acacias and hard grasses is developed.

The most interesting plant of the northern part of the desert is an ancient relic of velvichia.

The South African plateau, with its inherent variety of landscapes, has a rich and varied fauna.

But the number of wild animals is now markedly reduced, and many of their species are disappearing. The number of herbivorous animals - antelopes, zebras, giraffes - has especially decreased, and predators have also been greatly exterminated. Lions, leopards, wild cats have almost completely disappeared, hyenas and jackals are more common. The largest nature reserve in the region - national park Kruger in South Africa. Almost all African animals are collected here.

cape mountains located in the extreme southwest and south of the mainland, between the mouth of the Olifants River in the west and the city of Port Elizabeth in the east.

They stretch along the coast for 800 km, their average height is 1500 m. They are separated from the Great Ledge of the South African Plateau by the Big Karoo depression.

Fold-forming processes here took place from the second half of the Carboniferous to the second half of the Triassic, which includes their main phases.

Therefore, the age of the Cape Mountains is somewhat younger than typical Hercynian structures. Subsequently, they were destroyed and smoothed, and then rejuvenated by later uplifts.

The Cape Mountains consist of several anticline ridges that have a blocky character. The ridges are separated by wide longitudinal synclinal valleys and narrow transverse gorges.

The main part of the Cape Mountains is the southern system of latitudinal ranges.

Here are the highest (up to 2324 m) and long mountains Zwartberg (Small and Big) and Langeberg, between which lies the intermountain plateau of the Little Karoo. To the east, the ridges decrease and break into the sea with rocky capes. In the extreme south, they break up into small isolated ridges and massifs rising among the coastal plain. Another system of ridges is extended along Atlantic Ocean in a north-northwest direction.

In the southwest and south, the mountains come at an angle to the coast, indented with convenient bays.

The climate of the Cape Mountains is subtropical. In the southwest, it is of the Mediterranean type, with rainy, warm winters and dry, hot summers. Temperatures are tempered by altitude and sea. In Cape Town average temperature January + 21 ° С, July + 12 ° С. Rains begin in April, are heavy from June to September, and then stop as moist westerly winds give way to subtropical anticyclone winds.

In winter, snow falls on the tops of the mountains. In the western part of the mountains, on their windward slopes, the greatest amount of precipitation falls (up to 1800 mm per year). To the east, their number decreases to 800 mm. East of 22° E. in the precipitation regime, the typical features of the Mediterranean climate disappear, and the summer maximum begins to predominate due to the penetration of humid oceanic monsoons onto the mainland.

There is little precipitation on the coastal plain (in Cape Town - 650 mm per year). The climate of the inner parts of the mountains is subtropical continental.

The Cape Mountains are covered mainly with vegetation of the Mediterranean type, with a predominance of evergreen hard-leaved shrubs and herbaceous perennials.

Here the landscapes have much in common with the Atlas Mountains. They are also characterized by brown (typical and leached) and mountain forest brown soils.

However, the floristic composition of vegetation is different, specific to the Cape flora. very typical times

personal heathers, proteas, pelargoniums, mesembryanthemums, aloe, cactus-like spurges, crassula, etc. Interesting Cape nightshade with yellow poisonous fruits, silver tree with silvery fluffy leaves, Cape water lily with red flowers, wild watermelon, etc.

There are few trees among the Cape flora. Species of evergreen shrubs and perennial grasses predominate.

Thickets of evergreen hard-leaved shrubs form the fynbosh formation (an analogue of the Mediterranean maquis), which arose on the site of reduced forests that previously covered mountain slopes.

The composition of the fynbos includes representatives of the Proteaceae family (including the silver tree), heather, legumes, bellflowers and rue.

Forests have survived only on inaccessible, well-moistened mountain slopes.

In the west, in deep and inaccessible valleys, you can find a few groves of southern conifers (podo-carpus, etc.), in the east, on the slopes of the mountains, there are dense monsoon mixed forests, consisting of coniferous and evergreen deciduous trees (olive laurel, Cape beech, etc. .) trees. Palm groves grow on the coastal lowlands.

Vast areas in the Cape Mountains are covered with herbs with a predominance of bulbous, tuberous and rhizomatous forms from the amaryllid, iris, orchid and labiate families.

Immortelle, cineraria and other Compositae are characteristic. Semi-desert landscapes with succulent shrubs and semi-shrubs are developed on especially dry and hot lee slopes and in hollows. Thickets of acacia and aloe are common along the rivers in the Small Karru depression, in other parts the vegetation is represented by rare shrubs.

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These are humid forests with a dense network of full-flowing rivers. The eastern part stands out as sublime, the southern - boundless.

North Africa- the largest part of the continent. It is based on the plate of the African-Arabian ancient platform. The relief of plateaus and hills 300-400 m high prevails. Between them rise the rocky highlands of Ahaggar, Tibesti, Darfur, Jos, formed on the crystalline shields of the ancient platform. In the northwest, the folded Atlas Mountains adjoin the platform.

atlas mountains- a mountainous country, consisting of a system of mountain ranges, intermountain plateaus and depressions. Here on the coastal plains and windward slopes of the mountains with dry, hot summers and mild, wet winters, and on the intermountain plateaus and inner slopes of the ridges, it is dry and severe due to the high altitude. The nature of the Atlas has been greatly altered by man.

The largest tropical desert in the world, its length is 6000 km from west to east and 2000 km from north to south. It owes its existence to the continental tropical climate with precipitation less than 50 mm per year and high temperatures.

Due to the different composition of the rocks, different types deserts: rocky-gravelly, pebbly, sandy, clayey. sandy deserts with dune relief occupy only about 20% of the area of the Sahara.

There is almost no surface water in the Sahara. The only large one that crosses receives food outside of it.

Sudanese plains lie south of the Sahara. They are located in the subequatorial climate zone. The duration of the rainy season decreases from south to north from 10 to 2 months. There are many rivers in the western and eastern parts of the Sudanese plains. The largest of them is the White Nile,. The central part of the plains is an area in the lake, which changes its size and shape depending on the precipitation.

The natural conditions of the Sudanese plains are the most favorable for human life. The population has long been involved in cattle breeding here.

Central Africa covers the coast of the Gulf of Guinea and the basin. The equatorial climate dominates here, there is a dense network of full-flowing rivers.

The northern coast of the Gulf of Guinea is formed by uplands and plateaus, descending in steps to the coastal lowlands. An active volcano (4100 m) is located in the east of the region. On its slopes facing the bay, a record amount of precipitation for Africa falls - 9000 mm per year. The largest river Niger forms a large delta at its confluence with the Gulf of Guinea. Nature has been heavily modified by man, since the area has a long history of development and a high population density.

The central part of the Congo Basin is occupied by moist equatorial forests. They consist of hundreds of species of trees, vines, shrubs and herbs. The animal world is also diverse: dwarf giraffes okapi, water deer, elephants, hippos, various monkeys, birds. Along the coast of the Gulf of Guinea, forest areas have been greatly reduced due to logging and burning, giving way to light forests and savannahs or plantations of tropical crops.

South Africa located south of the watershed of the Congo and Zambezi rivers. divided into three natural regions.

The South African Plateau is a system of plateaus formed by the protrusions of the platform foundation. The plateau rises to the outskirts of the mainland, and there are depressions in the inner parts. Among them, the largest -. In the southeast, the Dragon Mountains adjoin the plateau. The plateau is located in, but the temperatures here, due to the significant height, are not as high as in North Africa. Natural areas in accordance with the decrease in precipitation are replaced from east to west. Tall grass savannas are common in the east. These are beautiful pastures and fertile plains. Acacias, aloe, spurges, herbs with powerful rhizomes grow here, blooming brightly during the rainy period. To the west, desert savannas predominate, occupying most of the Kalahari. In the Kalahari there are barren rocky areas. On the coast washed by the cold current is the Namib Desert.

There are few rivers with a constant flow, only navigable. On it is located the majestic. The South African plateau has a rich wildlife. In many areas, hunting is the main occupation of the population.

cape mountains- These are low and medium-height ranges, suitable in the south-west of the mainland to the coast, indented with convenient bays. Subtropical and shrubs with a large number of endemic species grew here in the past. From here, a variety of ornamental plants spread throughout the world. However, the natural vegetation is almost not preserved.

Madagascar- an island region, the relief and climate of which have much in common with the relief and climate of neighboring regions of the mainland. The organic world is characterized by great originality due to the long development in conditions of isolation. Among wild animals there are almost no ungulates and predators, poisonous snakes,

East Africa- the highest part of the continent, called the "roof of Africa". There are two natural areas -

East Africa is an area of dense settlement, and the land for agriculture has been used for a long time. On the Ethiopian highlands, the belt of mountain savannahs up to a height of 2.5 km is most favorable for human life. This belt is considered the birthplace of the coffee tree, durum wheat, rye, barley and some other cultivated plants.

Nowhere in the world is there such a variety of large animals as in East Africa. However, long-term extermination caused a decrease in their number, so national parks have been created in many countries. Kagera, Mnunt-Kenya, Serengeti, Kivu are world famous. The exotic nature and the possibility of sport hunting attract a large number of foreign tourists to the parks, which brings income to the countries of this region.

The East African Plateau is located on both sides of the equator, between the Congo Basin in the west and the Indian Ocean in the east, Eastern Sudan, the Ethiopian Highlands, the Somali Peninsula in the north and the lower reaches of the Zambezi in the south and covers a space from 5 e. sh. to 17°S sh.

The plateau is a mobile, tectonically active part of the African platform. The greatest system of rifts and the greatest heights of the mainland are concentrated here. It is composed of Precambrian crystalline rocks, among which granites are widely developed. The ancient basement is covered in places by Paleozoic and Mesozoic, mainly continental deposits.

The plateau has long been an elevated area. In the Cenozoic, grandiose tectonic faults and rifts arose. They continue the grabens of the Red Sea and the Ethiopian Highlands and branch south of Lake Rudolf, forming the western, central, and eastern fault systems. Rifts are expressed in the relief as narrow depressions with steep stepped slopes; high mountain ranges rise along their edges (the Rwenzori massif, the volcanoes of Kilimanjaro, Kenya, Elgon, etc.). Volcanic activity along the faults has not ended at the present time. The areas not affected by faults have the appearance of a typical peneplain with insular mountains. There are also extensive basins on the plateau (Lake Victoria).

Western fault system runs along the western edge of the plateau and includes deep grabens occupied by the Albert Nile river valley, Albert lakes (Mobutu-Sese-Seko), Edward, Kivu, Tanganyika. From Lake Tanganyika, it stretches through the basin with the endorheic Lake Rukva, the tectonic basin of Lake Nyasa, the valley of the Shire River and the lower reaches of the Zambezi. Fault tectonics is especially pronounced here. This is one of the most seismic zones of the mainland and the arena of modern volcanism.

The grabens of the Albert and Eduard lakes are separated by the Rwenzori horst massif, the most high peak Africa (5119 m) after Kilimanjaro (5895 m) and Kenya (5199 m). The massif is composed of gneisses, crystalline schists and intrusions of basic rocks, has glacial forms of Quaternary and modern glaciation (kars, cirques, trough valleys, terminal moraines), giving an alpine character to the topography of its peaks.

Between the grabens of Lakes Eduard and Kivu is located Virunga volcanic region(seven volcanoes). Here, in addition to active volcanoes new volcanic cones are also formed. Ancient lavas cover the tectonic trough between the basins of the Kivu and Tanganyika lakes.

Adjoins the northern segment of the western fault system from the east lake plateau(Uganda Plateau), located between lakes Edward, Albert, Victoria and the White Nile basin. The plateau has a wavy surface, is composed mainly of crystalline rocks and reaches a height of 1000 to 1500 m. The central part of the plateau is occupied by a swampy plain with Lake Kyoga. The plateau breaks off with stepped slopes to the East Sudan Basin, in the east it merges with the volcanic plateau of Kenya.

Central fault system serves as a continuation of the Ethiopian graben, runs in the meridional direction from Lake Rudolf in the north to Lake Nyasa in the south, where it merges with the western fault system.

In the northern part of the central faults, within the volcanic plateau of Kenya, the volcanic relief is especially pronounced. Extinct volcanoes Kilimanjaro, Kenya, Elgon and a group of giant craters rise along tectonic cracks, the edges of which are covered with basalts and tuffs. In a group of giant craters, the Ngorongoro volcano stands out with a huge caldera.

Between the western and central fault system, on the one hand, and Lakes Victoria and Nyasa, on the other, is located Unyamwezi plateau. It is composed of granites and is heavily swamped. To the east are the Nyasa and Masai plateaus. These are peneplains on a granite base, broken by faults and crowned with rounded crystalline remnant peaks.

Eastern fault system represented mainly by unilateral faults. From the west, they limit by ledges a narrow coastal lowland, composed mainly of permeable Tertiary sandstones and limestones.

The climate of the East African Plateau is subequatorial, hot, variable-humid, with a pronounced climatic zonality on high mountain ranges. Only in the vicinity of Lake Victoria, on the Lake Plateau, does it approach the equatorial one both in terms of the amount and regime of precipitation, and in the even course of temperatures, which, however, due to the high altitude of the area, are 3-5 ° C lower than the average monthly temperatures of the equatorial strip in the Congo Basin.

Trade winds and equatorial monsoons dominate within the plateau. In the winter months of the Northern Hemisphere, the northeast trade wind, without changing its direction, is drawn into a baric depression over the Kalahari. Passing over the ocean from Southeast Asia to Africa, it is moistened and releases a small amount of precipitation, mainly orographic. In the summer of the Northern Hemisphere, the south trade wind (southeast wind) intensifies; passing through the equator, it acquires the character of a southwest monsoon. The main wet period is also associated with them; most of the precipitation falls on the windward slopes of the mountains.

High temperatures are observed only at low altitudes, especially on the coast of the Indian Ocean. In Dar es Salaam, for example, the average temperature of the warmest month (January) is +28 °C, the coldest (August) is +23 °C. It becomes cooler with height, although the annual course remains uniform. In the mountains at an altitude of more than 2000 m, the temperature is below 0 ° C, above 3500 m snow falls, and on the highest massifs - Rwenzori, Kilimanjaro and Kenya, there are small glaciers.

Humidification of various parts of the East African Plateau is not the same. The greatest amount of precipitation (up to 2000-3000 mm and more) is received by high mountain ranges. From 1000 mm to 1500 mm of precipitation falls in the northwest and southwest of the country, as well as on the coast of the Indian Ocean south of 4 ° S. sh., where the mountainous meridional coast delays moist winds from the Indian Ocean. In the rest of the plateau, 750-1000 mm of precipitation falls annually, falling in the extreme northeast and in closed depressions to 500 mm or less. Kenya is the driest region of the plateau, with a long rainless period of 7 to 9 months.

For territories located between 5 ° with. sh. and 5°S sh., the equatorial precipitation regime is characteristic, with two rainy seasons (March-May and November-December), separated by two periods of their relative decrease. To the south, they merge into one rainy season (from October-November to March-April), followed by a dry period.

The East African Plateau occupies a watershed position between the basins of the Atlantic, Indian Oceans and the Mediterranean Sea. In the north-west of the region, the Nile originates, to the system of which the lakes Victoria, Kyoga, Albert and Edward belong. Lakes Tanganyika and Kivu belong to the Congo river system; Lake Nyasa drains into the Zambezi. In the central part of the plateau there are drainless lakes (Rudolf, Ruk-va, Baringo, etc.). In terms of size, depth, impact on runoff and climate, the plateau lakes are comparable to the Great Lakes of North America.

The tectonic fragmentation of the plateau, the variety of relief and climatic conditions determine the diversity and variety of landscapes. The interior is dominated by typical savannahs with rather large tracts of light forests and shrubs that shed their leaves during the dry season. The vegetation consists of grasses, acacias, mimosas, baobabs, tamarisks, milkweeds, etc. Red-brown soils are developed on the plains under typical savannahs and light forests, black tropical soils are developed in poorly drained relief depressions, and young brown tropical soils are on the main volcanic rocks.

In arid northeastern regions (the plateau of Kenya, north of 2°-3° N), on red-brown soils, deserted savannas and thickets of thorny shrubs of xerophytic, leafless acacias are developed for most of the year, in places turning into semi-desert. Similar and more arid landscapes are characteristic of deep depressions of the central fault system, where drainless lakes are half-filled with sand, covered with a crust of salts, and surrounded by solonchaks with halophytic vegetation.

The northern part of the coastal lowland near the coast of the Indian Ocean also has a sparse, semi-desert vegetation cover. In the southern part of the lowland, semi-deserts are replaced by savannahs, red-brown soils give way to red ones; mixed deciduous-evergreen forests appear along the rivers and on the windward slopes of the mountains. Mangroves are developed along the coast.

In abundantly humid areas, moist equatorial forests on red-yellow soils and mixed deciduous-evergreen forests on red soils are common. They are mostly cut down and replaced by secondary formations - wet tall grass savannahs. Evergreen and mixed forests are found mainly in the west (Lake Plateau), where they merge with the hylaea of the Congo Basin, as well as on the windward wet slopes of high mountain ranges.

On the high massifs of the country, altitudinal landscape zonation is well expressed. On the slopes of Kilimanjaro and in other mountains, up to a height of 2100-2800 m, evergreen equatorial forests and mountain hyleys with lianas and epiphytes grow. There is a lot of precipitation here. Trees are represented by coniferous and deciduous species. In the undergrowth, tree-like ferns and heathers form a continuous bowl. Lots of lichens and mosses. Mountain forests at altitudes of 1100-2000 s have been greatly altered by man and have given way to park landscapes, where grassy spaces alternate with groves. Above the mountain hyla (up to 3100-3900 m) there are thickets of bamboo and tree-like juniper, giving way to mountain high-grass meadows with giant tree-like ragworts (senecio) and lobelia. Starting from a height of 4200-4500 m, sparse lichen vegetation grows on stony placers and rocks. The peaks of Kilimanjaro, Kenya, Rwenzori with 4800 m are covered with eternal snows and glaciers.

The fauna of the plateau is rich and varied. Monkeys, elephants, giraffes, rhinos, buffaloes, zebras, antelopes (kudu, eland, etc.) find rich food in savannahs, woodlands and forests. From predators there are lions, leopards. In the river and lake thickets and reservoirs there are hippos, crocodiles, birds nest. The avifauna is richly represented: guinea fowl, marabou, secretary bird, African ostrich, shoebill, etc. Dryer places are inhabited by lizards and snakes. On the plateau are world-famous national parks and reserves. In the Kivu National Park (Zaire), which includes mountain range Rwenzori, protected landscapes and rich wildlife of forests, savannas, volcanic areas, including mountain gorillas. The national parks of Kagera in Rwanda, Serengeti, Ngorongoro in Tanzania and others are world famous.

South Africa

South Africa occupies a high part of the mainland south of the watershed plateau between the Congo and Zambezi river basins. The relief is dominated by plateaus and plateaus. The country is distinguished by a wide variety of landscapes due to the sharp contrasts in moisture and the relief of individual areas. The main part is occupied by the South African Plateau, to which the Cape Mountains adjoin from the south. A special natural area forms the island of Madagascar.

South African plateau lies within the Precambrian African Platform, occupying the Kalahari and Karra syneclises. The Precambrian basement in the Kalahari syneclise is shallow and in some places comes to the surface, forming ledges and uplifts; the sedimentary cover is represented by horizontal Upper Cretaceous and Cenozoic continental deposits, mainly sandstones and sands (Kalahari Formation). The blue-clise of the Karoo is a foothill foredeep of the platform, which arose in connection with the formation of the Cape mountain system; within its limits, the crystalline basement is deeply lowered and hidden under a thick layer of lagoonal sediments; Permian-Triassic age, mainly sandstones and shales (karoo formation); in some places these rocks are intruded by lavas. The deposits of the Karoo Formation make up the southern and southeastern plateaus.

The Kalahari Basin is surrounded on all sides by marginal plateaus and uplands with numerous insular remnant massifs and mountains. They gradually rise towards the outskirts up to 1200-2500 m and more. The greatest width of the plateau is reached in the east and south of the region. To the east are the Matabele and Weld Plateaus, and to the south the Upper Karoo Plateau.

South of the Limpopo River is located Weld plateau. It is a series of stepped plateaus (High, Middle, Shrub, and Low Weld) descending towards the Kalahari Basin and the Limpopo River Valley. The plateaus are composed of sandstones, shales and conglomerates of the karru formation, in places intrusive and volcanic rocks.

Upper Karoo, located south of the Orange River, closes the Kalahari Basin in the south, descending to it in several steps. The plateau is composed of horizontally occurring sandstones and shales, penetrated by numerous intrusions, forming remnant elevations, sometimes sharp peaks.

The marginal plateaus of the South African Plateau in the west, east and south drop off steeply to the coastal plains and depression Big Karoo by the Great Ledge, the outer slopes of which are deeply dissected by river erosion. The Ledge reaches its highest height in the east, in the Dragon Mountains. The southern part of the mountains - the Basuto Highlands, which has basalt lavas - is the highest massif of the Kalahari ring frame. Its peak Thabana-Ntlenyana (3482 m) is the highest in South Africa.

The marginal plateaus in the east are adjoined by a vast Mozambique lowlands. It is composed of Cretaceous and Tertiary deposits and is broken up by tectonic fissures in the northern part. In the west, the plateaus of the marginal plateaus break off to the coastal plain. Its section between the rivers Kunene and Orange is the Namib Desert. The desert stretches from north to south for more than 1500 km, occupying a narrow strip of ancient crystalline peneplain, crushed by faults.

The plateau lies in the subequatorial, tropical and subtropical climatic zones. However, tropical climate types predominate. In the summer of the Southern Hemisphere, a local baric depression forms over the Kalahari. The north of the region (up to the middle reaches of the Zambezi) is irrigated by the summer equatorial monsoon. The entire eastern part is influenced by the southeast trade wind, which brings humid tropical air from the Indian Ocean, heated over the warm Mozambican current. Abundant precipitation falls on the Mozambique lowlands, the slopes of the Great Escarpment and the eastern marginal plateaus. To the west of the Great Ledge and the marginal plateaus, marine tropical air quickly transforms into continental air and the amount of precipitation decreases. The western coast is under the influence of the South Atlantic High, which is intensified by the powerful cold Benguela Current. Atlantic air warms up over the surface of the mainland and emits almost no precipitation. On the western marginal plateaus there is a front between the maritime Atlantic and continental tropical air; here the amount of precipitation increases slightly. In the winter of the Southern Hemisphere, a local anticyclone forms over the plateau, merging with the South Atlantic and South Indian baric maxima. Downward currents of air determine the dry season; precipitation does not fall.

The South African Plateau is an area of relatively high temperatures, significant daily and annual fluctuations. But on the plateau temperatures are moderated by a considerable height. Over most of the plateau, summer temperatures are + 20 - ^ - + 25 ° С, not rising above +40 ° С; winter temperatures are +10 - + 16°С. On the Upper Karoo Plateau, frosts occur in winter, and snow falls on the Basuto Highlands.

The plateau is an area of predominantly meager precipitation, which is distributed very unevenly over its territory. Their number decreases when moving from east and north to west and south. In the north of the region, up to 1500 mm of moisture falls annually; here the rainy season brought by the equatorial monsoons lasts up to 7 months. A lot of precipitation falls on the east coast, where the barrier role of the Great Ledge is especially pronounced. Precipitation is brought here by the southeast summer trade wind (more than 1000 mm per year, and on the slopes of the Basuto highlands - over 2000 mm). The most frequent and heavy rains fall from November to April. On the eastern marginal plateaus, precipitation decreases on the Weld Plateau (750-500) and Matabele (750-1000 mm). The summer maximum precipitation is also preserved in the interior regions, but their annual amounts are decreasing. On the central Kalahari plains, the rainy season is reduced to 5-6 months, the annual precipitation does not exceed 500 mm. To the southwest, the amount of precipitation decreases to 125 mm per year. The driest part of the region is the coastal Namib desert (less than 100 mm of precipitation per year). Little precipitation will fall on the western marginal plateaus (up to 300 mm per year).

The river network on the plateau is poorly developed. Most of the channels of the Kalahari, the western and southern marginal plateaus do not have permanent watercourses. The largest river is the Zambezi. The large rivers of the region - the Orange and the Limpopo collect their waters from the Matabele plateau and the High Weld. The Okovango River is the main internal water system of the Kalahari Basin. During rains, the Okovango basin sometimes overflows with water, its excess being directed from Okovango to the Zambezi and the Makarikari salt marsh.

The large size of the South African plateau, differences in relief and climate create a variety of landscapes.

Almost all landscapes of the mainland are represented in South Africa.

Along with zonal differences, there are also sectoral differences. The eastern humid oceanic, mid-continental and western relatively cool desert oceanic sectors are well expressed in the region.

In the eastern sector, where there is a lot of precipitation, zones of seasonally humid forests change from north to south: subequatorial (up to 20 ° S), tropical (20-30 ° S), and subtropical monsoon. On the slopes of the Dragon Mountains, altitudinal zonality of the forest-meadow type is well expressed. Seasonally humid forests occupy the windward slopes up to a height of 800-1000 m. Above, shrub thickets and mountain-valley, mainly coniferous forests, meadows, and rocky placers appear; similar vegetation is characteristic of the Basuto Highlands (thickets of bushes, individual trees, meadows and stony placers).

In the middle continental sector (Kalahari Basin and marginal plateaus), natural zones of savannas, woodlands and shrubs of the subequatorial and tropical belts, tropical and subtropical semi-deserts, and subtropical mountain steppes are developed. However, semi-desert landscapes dominate. Rare vegetation consists of xerophytic herbs, shrubs and individual acacias, spurges, aloe. The Kalahari is characterized by wild watermelons, the stems of which cover large areas.

In the western oceanic sector is the tropical Namib Desert. In its southern part, along the valleys of dry channels and in places where groundwater is shallow, rather dense vegetation of succulent shrubs and semi-shrubs, low-growing acacias and hard grasses is developed. The most interesting plant of the northern part of the desert is an ancient relic of velvichia.

The South African plateau, with its inherent variety of landscapes, has a rich and varied fauna. But the number of wild animals is now markedly reduced, and many of their species are disappearing. The number of herbivorous animals - antelopes, zebras, giraffes - has especially decreased, and predators have also been greatly exterminated. Lions, leopards, wild cats have almost completely disappeared, hyenas and jackals are more common. The largest reserve in the region is the Kruger National Park in South Africa. Almost all African animals are collected here.

cape mountains located in the extreme southwest and south of the mainland, between the mouth of the Olifants River in the west and the city of Port Elizabeth in the east. They stretch along the coast for 800 km, their average height is 1500 m. They are separated from the Great Ledge of the South African Plateau by the Big Karoo depression.

Fold-forming processes here took place from the second half of the Carboniferous to the second half of the Triassic, which includes their main phases. Therefore, the age of the Cape Mountains is somewhat younger than typical Hercynian structures. Subsequently, they were destroyed and smoothed, and then rejuvenated by later uplifts.

The Cape Mountains consist of several anticline ridges that have a blocky character. The ridges are separated by wide longitudinal synclinal valleys and narrow transverse gorges.

The main part of the Cape Mountains is the southern system of latitudinal ranges. Here are the highest (up to 2324 m) and long mountains Zwartberg (Small and Big) and Langeberg, between which lies the intermountain plateau of the Little Karoo. To the east, the ridges decrease and break into the sea with rocky capes. In the extreme south, they break up into small isolated ridges and massifs rising among the coastal plain. Another system of ridges is extended along the Atlantic Ocean in a north-north-west direction. In the southwest and south, the mountains come at an angle to the coast, indented with convenient bays.

\ The climate of the Cape Mountains is subtropical. In the southwest, it is of the Mediterranean type, with rainy, warm winters and dry, hot summers. Temperatures are tempered by altitude and sea. In Cape Town, the average temperature in January is + 21 ° С, in July + 12 ° С. Rains begin in April, are heavy from June to September, and then stop as moist westerly winds give way to subtropical anticyclone winds. In winter, snow falls on the tops of the mountains. In the western part of the mountains, on their windward slopes, the greatest amount of precipitation falls (up to 1800 mm per year). To the east, their number decreases to 800 mm. East of 22° E. in the precipitation regime, the typical features of the Mediterranean climate disappear, and the summer maximum begins to predominate due to the penetration of humid oceanic monsoons onto the mainland. There is little precipitation on the coastal plain (in Cape Town - 650 mm per year). The climate of the inner parts of the mountains is subtropical continental.

The Cape Mountains are covered mainly with vegetation of the Mediterranean type, with a predominance of evergreen hard-leaved shrubs and herbaceous perennials. Here the landscapes have much in common with the Atlas Mountains. They are also characterized by brown (typical and leached) and mountain forest brown soils. However, the floristic composition of vegetation is different, specific to the Cape flora. Various heathers, proteas, pelargoniums, mesembryanthemums, aloe, cactus-like spurges, crassula, etc. are very characteristic. Cape nightshade with yellow poisonous fruits, a silver tree with silvery fluffy leaves, a Cape water lily with red flowers, wild watermelon, etc. are interesting. flora few trees. Species of evergreen shrubs and perennial grasses predominate.

Thickets of evergreen hard-leaved shrubs form the fynbosh formation (an analogue of the Mediterranean maquis), which arose on the site of reduced forests that previously covered mountain slopes. The composition of the fynbos includes representatives of the Proteaceae family (including the silver tree), heather, legumes, bellflowers and rue.

Forests have survived only on inaccessible, well-moistened mountain slopes. In the west, in deep and inaccessible valleys, you can find a few groves of southern conifers (podo-carpus, etc.), in the east, on the slopes of the mountains, there are dense monsoon mixed forests, consisting of coniferous and evergreen deciduous trees (olive laurel, Cape beech, etc. .) trees. Palm groves grow on the coastal lowlands.

Vast areas in the Cape Mountains are covered with herbs with a predominance of bulbous, tuberous and rhizomatous forms from the amaryllid, iris, orchid and labiate families. Immortelle, cineraria and other Compositae are characteristic. Semi-desert landscapes with succulent shrubs and semi-shrubs are developed on especially dry and hot lee slopes and in hollows. Thickets of acacias and aloe are widespread along the rivers in the Small Karru depression, in other parts the vegetation is represented by rare shrubs.

Madagascar - one of the largest islands of the Earth (590 thousand km 2). In size, it is second only to Greenland, New Guinea and Kalimantan.

Madagascar is an ancient crystalline, obliquely placed block of the African platform, separated from the mainland in the Mesozoic. The relief of the island is asymmetrical. All of it eastern part occupies a high Central plateau. It is composed mainly of crystalline (granites, diabases) and metamorphic (mica stanzas, gneisses and quartzites) rocks broken through and overlapped in places by volcanic formations. The surface of the plateau is an ancient peneplain, gently inclined from east to west and dissected by faults and rivers into isolated plateaus, remnant hills and massifs, between which there are depressions and wide valleys with a flat bottom, partially occupied by lakes and swamps. The prevailing heights of the Central Plateau are 800-1200 m, near the eastern outskirts - up to 1500 m. The highest heights are in the middle part (Ankaratra massif, 2644 m) and in the north (Tsa-ratanana volcanic massif, 2880 m, the highest point of the island).

In the east, the Central Plateau descends in two fault ledges, deeply dissected rivers to a narrow (10–20 km) coastal lowland composed of Quaternary deposits. From the west, it is adjoined by relatively low plateaus (less than 800 m high) and a wide strip of hilly lowland, on the ancient foundation of which Cretaceous and Cenozoic marine deposits lie.

The climate of Madagascar is mostly tropical and hot. In the north, the average temperature of the coldest month (July) is +20 °С, the warmest (January) is +27 °С. In the south, the average July temperature drops to + 13°C, the average January temperature drops to + 33°C. On the plateau, the climate is temperate, with temperatures decreasing with altitude. In Antananarivo at an altitude of 1400 m, the average January temperature is below + 20 °C, the average July temperature is +12 - + 13 °C. The amount of precipitation in different parts of the island is not the same. The main mass of precipitation is brought by the southeast trade wind from the Indian Ocean. Therefore, on east coast(lowlands and slopes of the plateau) rainfall is almost uniform throughout the year and the amount of precipitation reaches 3000 mm per year. On the eastern plateaus, the amount of precipitation decreases, but exceeds 1500 mm. In the west of the island there are rainy and dry periods. The amount of precipitation decreases from 1000 to 500 mm per year. In the extreme southwest, inaccessible to humid air currents, less than 400 mm of moisture falls annually.

Most of Madagascar is covered by a dense network of high-water rivers. major rivers are located in the western part. They start on the Central Plateau and flow into the Mozambique Channel. There are rapids in the rivers where they cross the ledges of the plateau. Rivers are high in summer (November-April) and low in winter. Many of them dry up in winter.

The flora and fauna of Madagascar is poorer than on the mainland, and is characterized by high endemism. This is the result of the long isolation of the island. Over 6,700 species of endemic angiosperms are known here. There are almost no ungulates, higher predators and real monkeys on the island.

The vegetation cover of the island has undergone great changes. The natural vegetation on 4/5 of the area of Madagascar has been brought down by man. Previously, the island was covered with moist evergreen forests in the east and dry deciduous forests and savannahs in the west. Now no more than 13% of the island's surface is occupied by forests.

Moist evergreen forests are now preserved only in small areas in the eastern part of the island (valuable iron, black, rosewood trees, many gum, rubber, traveler's tree).

The western part of the island is dominated by low-grass savannas with baobabs, palms and tamarinds. Tropical light forests are found only in small areas (most often in the form of gallery forests along the banks of rivers) and consist of rocks with foliage falling in the dry season. The southwestern outskirts of Madagascar are occupied by semi-desert landscapes. Prickly bushes and hard grasses grow here. Especially numerous are aloe, candelabra-like euphorbia, and various bulbous ones.

The fauna of the island is very peculiar. It has been preserved since the separation of Madagascar from the mainland. Lemurs (35 species) are widespread here. In other parts the globe they are absent or few (represented by one or two species). On the island there are representatives of primitive predators - civet; there are ferret cats, wild boars, endemic representatives of insectivores - tenrecs, some species of bats. The avifauna is rich, and it contains many endemic species, genera and even families (almost half of all birds are endemic). Reptiles are diverse, including chameleons, geckos, turtles, two types of crocodiles. Insects are numerous and varied.

see also photos of the nature of the South African plateau(with geographical and biological captions for photographs) from the section Natural landscapes of the world:

On the gentle slopes of the eastern plateaus, facing the interior of the continent, there is still quite a lot of precipitation; treeless terrain prevails there with a dense cover of tall grasses (). Such a landscape in South Africa is called "weld".

As we move to the west, the amount of precipitation decreases and the vegetation takes on an increasingly xerophytic appearance. It consists of various bulbs that turn green and bloom only during a short period of rains, low-growing thorny acacias, numerous types of aloe. In the Kalahari there are completely barren rocky areas where plants do not form a continuous cover (). Wild watermelons are very characteristic of the Kalahari, the lashes of which cover large areas. Apparently, all known cultivated types of watermelons originate from here. With a large lack of moisture, watermelons with their water reserves save people and animals from thirst.

The vegetation of the Namib Desert is even poorer, where there are only individual specimens of velvichia, fixed on the sands with powerful roots, and undersized thorny shrubs ().

The shores of drying lakes and swamps in the Kalahari depressions and the upper reaches of the Zambezi are covered with more moisture-loving vegetation (), which serves as a refuge for wild animals.