11. Physiographic characteristics of the Amazonian lowland and Brazilian plateau.
AMAZON LOWLANDS. Geographical position. The main features of the nature of the Amazon are determined by its flat topography, long-term continental development and equatorial position. This largest region of equatorial climate and tropical rainforest on the planet accounts for most of the basin of the deepest river system on Earth.
The boundaries of the Amazon are clearly delineated by the slopes of the Brazilian and Guiana highlands and the eastern foot of the Andes.
Geological structure and relief. The main part of its territory is occupied by the huge alluvial plain of the Amazon, formed from the merging of vast platform syneclises filled with marine and continental sediments. The axis of the region is the Amazon, which carries its waters from the foot of the Andes to the Atlantic Ocean somewhat south of the equator and collects its tributaries from both hemispheres.
Climatic conditions. The middle and western Amazon has a typically equatorial climate, with two periods of particularly heavy rainfall from February to June and October to January. On the northern and southern edges of the Amazon, periods of heavy rainfall merge into one, corresponding to the summer of each hemisphere. The wet season there is very long; during the dry season, precipitation also falls, although its amount is noticeably reduced. Temperatures throughout the Amazon are high and uniform, with little seasonal variation.
There is no very strong heat, but even temperatures are 24... 27 °C. Rain usually falls in the form of heavy and prolonged downpours in the afternoon, and in the evening and at night it begins clear weather. These climatic features favor the development of tropical rainforests with their diverse and lush vegetation.
Zap. Amazonia . The vegetation of the high floodplains (varzea) is similar to the interfluves (ete) and includes especially many palm trees, hevea, sumaumu-ceibu, cocoa tree, etc. The vegetation of the low floodplains (igapo) is very poor. Typically there is an abundance of animals adapted to life in trees: broad-nosed monkeys, sloths, the lesser anteater; Among the terrestrial animals there are the giant armadillo, tapirs, peccaries, etc. There are many birds, reptiles, amphibians, fish, insects and ants.
East Amazonia . The forests contain a significant admixture of deciduous trees. Only strips of Varzea and Igapo on alluvial soils remain evergreen. Animals of open spaces also appear: mazama deer, the average anteater and small armadillos, many rodents, termites.
Population and environmental issues. The Amazonian lowland is very sparsely populated. The main routes of communication are rivers; along which there are small settlements and two large cities: Manaus - at the mouth of the Rio Negro and Belem - at the mouth of the river. Pair; a motorway has been built to the latter from the city of Brasilia. Manganese ores discovered in 1945 are being developed (Serra do Naviu in the territory of Amapa), deposits of iron ore have been discovered nearby, and oil deposits have been discovered in the lower reaches of Madeira (Nova Olinda).
Due to ongoing climate change and deforestation, vast areas of the Amazon rain forest may develop into a cerrado, the predominant type of arid savanna in modern Brazil. Over the past few decades, scientists have noted a 70% reduction in forests. Deforestation has negatively impacted the fragile ecological balance of the Amazon forests and led to the extinction of many species of trees, plants and animals. As was previously thought, the Amazon was home to almost a third of all living organisms on the planet, including insects and plants. Since the late 70s of the 20th century, over 70% of all tropical forests in Brazil have been destroyed. In addition, the decomposition of wood residues and other vegetation as a result of logging and burning of forests leads to increased emissions of carbon dioxide into the atmosphere, which, in turn, increases the greenhouse effect.
BRAZILIAN PLATEAU. Geographical position. Between the flat, low-lying plains of the Amazon and Parana basins in the north and west and the Atlantic Ocean in the east, a territory with elevated and dissected relief extends for approximately 5 million km 2.
Relief. Within the highlands there is a wide variety of relief, which combines areas of crystalline plateaus with island hills composed of sedimentary rocks, volcanic plateaus and blocky ridges formed as a result of Cenozoic faults and uplifts. As a result of the fragmentation and uplift of the East Brazilian shield in the Neogene, ridges or “sierras” were formed, which reach heights of more than 2000 m. They are most clearly expressed in the relief of the Serra do Mar in the southeast and the Serra do Espinhaço north of the South Tropic. The highest point of the highlands - Mount Bandeira (2890 m) - is located within the Caparao National Park. The Parana and its numerous tributaries fall from the steps of the plateau, forming rapids and waterfalls, the energy of which is now being intensively used. The most famous is the grandiose Iguazu Falls (70 m) on the Parana tributary of the same name.
Climatic conditions. Due to its location within the subequatorial and tropical zones, the Brazilian Highlands receive a lot of heat throughout the year. In the central part, annual precipitation (1500-1200 mm) falls mainly within 4-6 months. in the summer of the southern hemisphere. The average January temperature is 25...27 °C, and the average July temperature is about 24 °C.
A significant change in climatic conditions is observed towards the east. In the northeastern part of the highlands, the wet season is reduced to 3 months a year and the amount of precipitation is reduced to 1000-400 mm, with annual amounts fluctuating sharply from year to year. The southeastern trade winds leave the bulk of the moisture on the coast, and relatively dry air currents penetrate into the highlands. Equatorial air does not always reach the northeastern bulge unchanged.
Vegetation and fauna. The Brazilian Highlands are dominated by savannas and tropical woodlands. "Campos" is the common name for savannas in Brazil. Campos-limpos are characterized by a complete absence of woody vegetation. The area is a continuous sea of grass and thus vaguely resembles the steppes of the temperate zone. Among the herbs - different kinds feather grass, bearded grass, wheatgrass, as well as representatives of the families Apiaceae, Lamiaceae and legumes. All these plants burn out and turn brown during the dry period, only small cacti and agaves retain their appearance unchanged all year round.
In Campos Cerrados, trees and shrubs grow along with herbs. Trees no more than 3-5 m high usually have an umbrella-shaped crown. Grasses in the shade of trees can reach 1-2m in height and grow so densely that during the wet season the area becomes impassable. Fires are common in savannas, sometimes covering vast areas.
In the forests, even close to populated areas, there live monkeys, which cause great damage to gardens and crops; in the savannas there are armadillos, anteaters, and also a large flightless bird, the rhea, which resembles an ostrich. There is an abundance of birds everywhere, especially parrots and hummingbirds; Typical predators are pumas and jaguars; snakes and other reptiles are very common.
There are many ants in forests and savannas. Some of them settle near human habitation and cause great trouble to people. An integral feature of the savannah landscape is termite mounds.
Population and environmental problems. The most populated area is the area adjacent to the Atlantic Ocean. The largest cities are located there - Sao Paulo (population 17.7 million people in 2000) and Rio de Janeiro (10.6 million people) - and industry is developed. In many large cities, the problem of air pollution, particularly from vehicle exhaust, is so severe that some, such as São Paulo, have imposed restrictions on the use of private cars. Despite adding alcohol to gasoline and reducing carbon dioxide emissions by about 30%, no significant improvement in urban air quality has been achieved.
The Paraná basin contains the largest areas of arable land on which crops are grown. a coffee tree, tobacco, bananas, grapevines. On irrigated lands river valleys, especially in the north, rice crops are common.
In the humid north, sugar cane and oil palm are grown, and in drier areas, coffee trees are grown. In the northeast, which suffers most often from droughts, cotton is grown on irrigated lands. In internal parts The highlands occupy vast areas of savannah and secondary thickets used as pastures.
BRAZILIAN PLATEAUGH
BRAZILIAN PLATEAUGH
located on the E. South. America, south of the Amazonian lowland. It is strongly elevated along the Atlantic coast (2890 m), gently inclined to the north and southwest. It represents protrusions of the crystalline base of the South American platform (Brazilian shield), between which there are troughs filled with sedimentary deposits and lavas. Deposits of polymetals, gold, iron and manganese ores, bauxite. Elevated plains predominate, over which blocky massifs and tabletops, mainly sandstone hills, rise. B. p. lies in subeq.” tropical and subtropical climatic zones. Precipitation ranges from 500 mm in the north to 1400-2000 mm in the center. The rivers are full of water and abound with rapids and waterfalls. Evergreen and deciduous forests, with shrub savanna (camposserrados) in the center.
Concise geographical dictionary. EdwART. 2008.
Brazilian plateau
(Plateau of Brazil), continental core South America, in its east. between the Atlantic Ocean, plains and lowlands: Amazonian, Pampa And Gran Chaco (mainly sampled in Brazil and Uruguay, as well as in Paraguay and Argentina). The length both in latitude and along the meridian is more than 3200 km. Heights increase from 500 m in the west to 2000 m or more in the east. The highest point is the city of Bandeira (2890 m). High (800–900 m) plateaus with steep, rocky slopes, separated by depressions and deep (up to several hundred meters) river valleys, predominate. The highest parts of the plateau form the ridges: Serra do Mar, Serra do Espinhaço , Serra Dorada, etc. On the coast, individual mountains in the form of towers and cones (the so-called sugar loaves) are typical. The plateau has ancient crystalline rocks at its base, which in the south are covered by lava covers of Mesozoic age. Deposits of gold, iron, polymetallic, manganese ores, bauxite, rock salt and coal. Extraction of precious and ornamental stones. The plateau lies in the subequatorial, tropical and subtropical climate zones. Precipitation ranges from 500 to 2000 or more mm per year. The air temperature in January (summer) is 20–29 °C, in July (winter) 12–25 °C. On the N. and NW. evergreen and deciduous trees grow rainforests, on the NE. dry woodlands, shrub savannas in the center, mixed forests and savanna (campos limpos) in the south. Animals and birds are varied and numerous. The rivers are high-water, with waterfalls and rapids, and have large reserves of hydropower, but water supply is limited. Settlements and roads in the interior. parts are few.
Dictionary of modern geographical names. - Ekaterinburg: U-Factoria. Under the general editorship of academician. V. M. Kotlyakova. 2006 .
Brazilian plateau
in the east of South America, between the plains and lowlands: Amazonian, Pampa and Gran Chaco, ch. arr. in Brazil and Uruguay, as well as in Paraguay and Argentina. The length, both in latitude and along the meridian, is more than 3200 km. The heights increase from 500–600 m in the west to 1000–2000 m in the east near the Atlantic Ocean, to the coastal plains of which it faces the highest and steepest slopes. Max. the mark is the city of Bandeira (2897 m), composed of gneisses and located 100 km from the ocean coast. Highly elevated plateaus (800–900 m) with steep rocky slopes predominate. hundreds of meters, separated by depressions and river valleys. The most elevated parts form the ridges: Serra do Mar, Serra do Espinhaçu, Serra Dorado, etc. Near the coast, sugarloaf-shaped island mountains separated from the plateau. The plateau is formed by a protrusion of the crystalline foundation of the ancient platform (Brazilian Shield), which in the south of the plateau is covered by Mesozoic lava covers. The world's largest iron ore deposits. Deposits of rare elements (niobium, tantalum, zirconium, etc.), polymetals, gold, rare metals, manganese ores, bauxite, rock salt and coal, gold and diamonds. The length along the meridian and increasing altitudes determine climate changes from subequatorial to tropical and subtropical. The amount and regime of precipitation varies from 500 to 2000 mm per year. The air temperature in January is 20–29 °C, in July 12–25 °C. The heights of the plateau somewhat soften the climate. The rivers are numerous and high-water, with waterfalls and rapids, and have large reserves of hydroelectric power, but navigation is limited. The largest: Parana, San Francisco, Araguaia, etc. In the north and north-west. evergreen and deciduous forests, in the north-east. open forest, shrub savanna in the center, mixed forests and shrub savanna in the south.
Geography. Modern illustrated encyclopedia. - M.: Rosman. Edited by prof. A. P. Gorkina. 2006 .
See what "BRAZILIAN PLATEAU" is in other dictionaries:
Modern encyclopedia
In the east of South. America, between 3 and 35 .S. sh., mainly in Brazil. altitude 250,900 m, highest up to 2890 m (city of Bandeira). It is composed of Precambrian crystalline rocks, protruding in the form of basement plains (height 250,900 m), separate... ... Big encyclopedic Dictionary
Brazilian plateau- BRAZILIAN PLATEAU, in the east of South America, mainly in Brazil. Height 250,900 m, highest up to 2890 m (Mount Bandeira). The relief consists of elevated plains, ridges (the so-called serras), predominantly sandstone hills... ... Illustrated Encyclopedic Dictionary
In the east of South America, between 3 and 35°S. sh., mainly in Brazil. Height 250,900 m, highest up to 2890 m (Mount Bandeira). It is composed of Precambrian crystalline rocks, protruding in the form of basement plains (height 250,900 m), individual ... encyclopedic Dictionary- Brazilian Plateau on the physical map of Brazil The Brazilian Plateau (port. Planalto Brasileiro) is a vast geographical region covering a significant ... Wikipedia
Amazonia- (Amazonia) Definition of the Amazon, flora and fauna of the Amazon Information about the definition of the Amazon, flora and fauna of the Amazon Contents Contents Definition Guiana Highlands Orinoco River Angel Falls Amazon... ... Investor Encyclopedia
Southern continent of the Western Hemisphere, between Pacific Ocean in the west and the Atlantic Ocean in the east, Caribbean Sea in the north and the Strait of Magellan in the south, from 12°28 N. w. to 53°55 south w. Connected by the Isthmus of Panama to North America.… … encyclopedic Dictionary
1) capital of Brazil. New town, built specifically as the capital of the state of Brasil, received the name Brasilia, derived from the name of the state. In Russian language the name of the capital is conveyed with the ending Ia Brazil, i.e. the differences present in Portuguese ... Geographical encyclopedia
Geographical position
Natural areas and flora
Minerals
Bibliography
Geographical position
The Brazilian Plateau occupies most of eastern South America from 3 to 35° S. sh., mainly in Brazil, the south - in Uruguay, in the southwest its edge extends into Paraguay and Argentina. Strongly elevated in the east and southeast above the Atlantic coast. The highest point here above sea level is Pico da Bandeira, the highest peak of the Brazilian Plateau and Brazil. Height 2890 m (Fig. 1). It is located in the Caparao massif, between the lower reaches of the Paraiba and Rio Dosi rivers. Composed of gneisses. The slopes are covered with tropical rainforests. In the north to the Amazonian Lowland and in the southwest to the Laplata Lowland it is gently inclined; in the north-west it breaks off to the depression of the upper Paraguay.
Rice. 1 Pico da Bandeira
Geological structure
The Brazilian plateau consists of ancient crystalline shields and syneclises filled with sedimentary and volcanic rocks.
The ancient Guiano-Brazilian shield, which forms the basis of the Brazilian Plateau, is composed of Precambrian gneisses and crystalline schists, penetrated by granitoids. The shield protrudes to the surface in the form of the West Brazilian and East Brazilian protrusions of the folded basement. They are separated by the Parnaiba (Maranhao) and San Francisco basins. The East Brazilian high corresponds to the Late Proterozoic fold system (Baikalides), in places including older cores. At the beginning of the Cenozoic, the Cretaceous alignment surface here was uplifted, deformed and disrupted, which led to the formation of block mountains. The fault steps formed ledges. On the steep eastern side, they sometimes reach a height of several hundred meters and give the impression of real ridges (“serres”). From the foot of such a serra, the area to the east gradually rises, and then drops steeply down, forming a new serra.
The Brazilian plateau is low (from 250-300 to 800-900 m) and has a slightly hilly, almost flat topography. Even the highest outlier peaks are usually smoothed out. The eastern regional massifs reach the greatest heights. They form the Great Escarpment, descending in two large steps to the ocean. Among the ridges of the lower stage, Serra do Mar (1889 m) and Serra dos Organos (2070 m), located north of Gunabara Bay, stand out. The proximity to Rio de Janeiro and Sao Paulo made them favorite place holiday for wealthy Brazilians and tourists. The second, higher stage of the Great Escarpment is formed by the Serra do Mantiqueira, rising almost a full kilometer above the Serra do Mar. The highest peaks in Brazil are located here - Bandeira (Peak of the Banner), 2890 m and Agulhas Negras (Peak of the Black Eagles). Along the right bank of the river. In Sao Francisco, the sharp residual Proterozoic ridges of the Serra do Espinhaço rise to 1500-2100 m (Fig. 2). In hot humid climates rocks They quickly collapse: the softer and looser ones are washed away by showers, leaving the hard ones. Individual blocks acquired a cone-shaped shape, for which they received the name “sugarloaf” (Fig. 3). One of them adorns the picturesque bay of Rio de Janeiro. Syneclises (in the states of Maranhão and Piaui, along the rivers of São Francisco and the upper Paraná, etc.) are usually represented by stratified plains, often with erosional ledges of the cuesta type, and in the most elevated areas - remnant sandstone table plateaus with steep ledges - chapadas (they are characteristic and for a non-folded foundation cover); only the Parana depression is occupied by a stepped lava plateau.
Rice. 2 Residual Proterozoic Fig. 3 "sugarloaf" in the bay crests of Serra do Espinhaçu Rio De Janeiro
The further you go to the east, towards the humid breath of the Atlantic, the more the trees close together into a continuous cover of deciduous evergreen forests and the terrain becomes higher and rockier. The eastern edge of the Brazilian Plateau, which breaks down to the ocean, is already mountain ranges, broken into separate huge blocks, soaring steeply above tectonic depressions. The eastern edge of the Brazilian Plateau, which breaks down to the ocean, is already mountain ranges, broken into separate huge blocks, soaring steeply above tectonic depressions.
In the center and north-west, basement plateaus predominate, alternating with high plateaus - chapadas. To the west, the mountainous terrain gives way to vast plains upstream Parana River - Parana Plateau. Downstream of the Paraná there are extensive lava plateaus. The ledges of hardened lava make all the left tributaries of the Parana “jump” down, as if on steps, forming numerous rapids and waterfalls (Fig. 5). There are 56 of them on the Tieta River alone. Parana itself falls from a height of 17 m by the Senti Quedas waterfall (Fig. 4).
Rice. 4 Senti Kedas waterfall Fig. 5 waterfall of the left tributary of the Parana River
Natural areas and flora
The Brazilian plateau in the northwest and north is covered with moist evergreen and deciduous evergreen forests.
In the center are shrublands and savannas - campos cerrados, formed on red coarse soils. During the rainy season, they are overgrown with turf-grass vegetation. Campos plants are well adapted to the alternation of dry and wet seasons, which last about six months. Deciduous low-growing trees and shrubs, growing here along with evergreens, are covered with small leaves with a waxy coating. Chaparro-curatella, licheira (“emery tree”), mangabeira, the milky juice and fruits of which are used as food by local residents, seem to have fruits (Fig. 6), very rich in vitamins, as well as agaves, cacti and some types of palm trees.
Rice. 6 I show the fruits
During the dry period, everything burns out, and in some places a dense crust forms in the upper horizons of lateritic soils. In the west, the “Campos Cerrados” transition into the marshy, low-lying Pantanal plain, which is flooded during the rainy season and during drought, which is a combination of swamps and lakes with areas of forests, shrubs and meadows.
In the northeast there is xerophytic-succulent woodland - caatinga (Fig. 7).
Rice. 7 Caatinga (Portuguese caatinga, in the Tupi language - white, light forest)
Poor soils barely cover the rocks, and there is almost no grass. There are prickly shrubs and all kinds of cacti everywhere. And above them are dry-loving shrubs and trees, columnar cacti and tree-like euphorbia. At some distance from each other, like skittles, bottle trees grow (Fig. 8). These thickets are almost devoid of foliage and provide no shelter at all from the burning rays of the sun or from downpours. During the winter-spring dry period, which lasts 8-9 months, precipitation falls less than 10 mm per month. Wherein average temperature air temperature is 26-28 C. At this time, many plants shed their leaves. Life freezes until the autumn rains, when more than 300 mm of precipitation falls per month with an annual amount of 700-1000 mm. As a result of rainfall, the water level in rivers rises rapidly. Floods occur regularly, destroying houses and washing away topsoil from fields.
In the east there are humid tropical evergreen and summer green forests. There by Atlantic coast there are tropical rainforests, which in the coastal part are largely reduced to plantations of tropical crops. The eastern windward slopes and high plateaus of the Brazilian Plateau are characterized by a pronounced altitudinal zone. Tall grass evergreen forests, similar in appearance and species composition With Amazonian jungle. Higher up they give way to tree ferns (Fig. 9, 10) and bamboos, and at an altitude of 1800 m deciduous trees and coniferous araucaria appear. Above 2200-2400 m, mountain meadows begin, giving way to peat bogs, mosses and lichens
In the south there are mixed coniferous forests with evergreen deciduous and treeless savanna - campos limpos; lateritic and chestnut soils are developed under the savannas. On the arid interior plains of the highlands, composed of porous sandstone and, in some places, clayey rocks, treeless grassy savannas (prairies) are common, with gallery forests along river valleys. "Campos-Limpos" are beautiful pastures.
The western leeward slopes of the eastern ridges of the highlands are characterized by seasonally wet deciduous forests.
Fig.8 Bottle tree
Rice. 9 tree ferns
Rice. 10 tree ferns
The Brazilian plateau lies in the subequatorial, tropical and subtropical climate zones. Average temperatures in January vary from southwest to northeast from 22 to 29 °C (maximum up to 42 °C), in July - from 12 to 25 °C, minimum - 6 °C (below the tropics). The amount and regime of precipitation within the Brazilian Plateau are very different: in the north and in the center precipitation falls mainly in summer, up to 1400-2000 mm per year (in the northeast less than 500 mm, the driest region), in the east - over 2000 mm, almost without drought, and in the south 1000-1800 mm throughout the year. The low mesas adjacent to the Amazon are humid and hot. tropical climate with heavy showers and thunderstorms. No less humid climate and on the slopes of the Serres Grand Escarpment facing the South Atlantic. The annual precipitation here is about 2000 mm. On fenced off on all sides by high serras and chapadas internal areas The Brazilian plateau receives from 500 to 1000 mm of precipitation per year, and about 90% of it falls on rainy season(January June). But even at this time, cruel, devastating downpours only wash the earth. The moisture evaporates before the soil has a chance to absorb it. It is not uncommon for the dry season to last throughout the year, causing severe droughts.
The river regime usually shows a sharp decrease in flow in winter and violent floods in summer. The flow from the north and northwest of the Brazilian Plateau belongs to the basins of the right tributaries of the Amazon (tributaries of the Madeira, Tapajos, Xingu and Tocantins with Araguaia), from the northeast and east - to the basins of the Parnaiba, São Francisco and other rivers flowing into the Atlantic Ocean , from the southwest and south - to the Parana and Uruguay basins. The rivers are replete with rapids and waterfalls, creating large reserves of hydroelectric power that do not interfere with navigation.
To the west, the mountainous terrain gives way to the vast plains of the upper reaches of the Parana River - the Parana Plateau. There are excellent conditions for growing coffee: the average temperature of the coldest month is not lower than +14 degrees, sufficient rainfall is about 1500 mm. in year. In winter, there is a pronounced dry period necessary for drying grains.
Animal world The Brazilian plateau is rich and varied. Common species include the jaguar (Fig. 11), porcupine (Fig. 12), anteater (Fig. 13), and the rare bush dog (Fig. 14). The plateau is also rich in snakes, there are anacondas (Fig. 15), boa constrictors (Fig. 16), bushmaster ( poisonous snake, rice. 17). In rivers, piranhas (Fig. 18) and caimans (Fig. 19) are dangerous. The swamps are home to the capybara (the world's largest rodent, Fig. 20), long-nosed tapir, and peccaries (Fig. 21). The fauna of the Brazilian plateau is rich in many species of birds.
Rice. 11 jaguar
Rice. 12 porcupine Fig. 13 anteater
Rice. 14 bush dog
Rice. 15 anaconda Fig. 16 Boa constrictor
Rice. 17 Bushmaster Fig. 18 piranha
Rice. 19 cayman Fig. 20 capybara
Rice. 21 bakers
Minerals
In central and southeastern parts Brazilian plateau concentrated largest deposits iron ores, beryl, niobium, rock crystal, in reserves of which Brazil holds first place in the capitalist world. Deposits of manganese, bauxite, copper, rare metals (tungsten, chromium, tantalum), and rare earth elements have been discovered in different parts of the Brazilian Plateau. There are scatterings of diamonds and semi-precious stones. Carbonados, black diamonds that are distinguished by their high hardness, are especially valued. The diverse climatic conditions of the Brazilian plateau allow the cultivation of almost all known agricultural crops - cereals, potatoes, tropical fruit plants. Large areas are occupied by pastures.
2nd quarter of the 19th century. (F. King and R. Fitzroy). The English hydrographer and meteorologist Robert Fitzroy (1805-1865), vice admiral, surveyed the southern coast of South America in 1828-30. In the 19th-20th centuries. exploration of the Brazilian plateau and the Amazonian lowland intensified [German W. Eschwege (1811-1814), Frenchman E. Geoffroy Saint-Hilaire (1816-22), participants in the Austro-Bavarian expedition of 1817-20 K. Martius, ...
Rio de Janeiro. Here you can also purchase products made of stone, leather and wood, made with your own hands by talented self-taught craftsmen. 4.1 Attractions of Rio de Janeiro ("January River") - former capital, the most visited city in Brazil. There is a huge statue of Jesus Christ on Mount Corcovado (part of the Tijuca National Park, which covers an area of more than 3,000 hectares) - ...
See Colony. MIGRATIONS OF POPULATION, the movement of people from one place to another. There are external and internal M. n. External M. n. arose in ancient times, continued during the era of the Great Geographical Discoveries, and received their greatest development in the era of capitalism. Until the middle of the 20th century. The main focus of emigration (eviction) was Europe and, to a lesser extent, Asia. Foci of immigration (inhabitation) ...
BRAZIL, Federative Republic of Brazil (Republica Federativa do Brasil), the largest state in South America. Washed by the Atlantic Ocean. It borders French Guiana, Suriname, Guyana, Venezuela, Colombia, Peru, Bolivia, Paraguay, Argentina and Uruguay. Area 8.5 million km2. Population 179.383 million people (2004). Capital of Brazil. Major cities: Sao Paulo, Rio de Janeiro, Salvador, Belo Horizonte, Brazil, Recife, Porto Alegre, Manaus. Large seaports: Rio de Janeiro, Santos, Rio Grande, Paranagua, Porto Alegre, Tubaran, San Sebastian.
The administrative division of Brazil is the Presidential Federal Republic. A federation consisting of 26 states and the Federal (Capital) District. The head of state and government is the president. The legislative body is the bicameral National Congress. Consists of the Federal Senate and the Chamber of Deputies.
Population of Brazil. St. 95% of us. - Brazilians, a nation formed as a result of the mixing of Portuguese and other European settlers with the aborigines - Indians (Tupi-Guarani, etc.) and with those exported in the 16-19 centuries. from Africa by black slaves (Yoruba, Bantu, Ewe, etc.). By ethnic composition whites 54%, mulattoes 38.5% and blacks 6%. Indians (over 1 million people) inhabit mainly the interior areas of the river basin. Amazon.
The official language is Portuguese. The majority of believers are Catholics (over 72%), the rest are Protestants (22.5%), and African cults are also preserved. Average. population density 21.4 people/km2. In the northeast, southeast and south of the country (40% of the territory) St. lives. 90% of the population, including approx. 50% of the population lives on a narrow strip of the Atlantic coast, which makes up 8% of the country's territory. Urban population 78% (1995). More than half of the country's population are young people under the age of 20. People over 50 make up only 10%.
Climate of Brazil
The vast territory of Brazil is divided into two main natural areas: the equatorial forest plains of the Amazon in the north and the mosaic of tropical landscapes of the Brazilian Plateau in the remaining 2/3 of the country.
In wet equatorial forests The Amazonian lowland (Amazonian jungle) is home to over 4,000 species of trees (every fourth tree in the world grows in the Amazon basin). These forests are considered lungs of the planet. Their accelerated deforestation causes legitimate concern among environmentalists around the world. The forests are rich in fauna: broad-nosed monkeys, sloth, anteater, opossum, jaguar, puma, ocelot, peccary pigs, tapir, capybara. Snakes, reptiles, and birds are numerous. The Amazonian lowland lies in the equatorial and subequatorial climate. Temperature all year round 24 - 28 °C, precipitation falls from 3000 to 3500 mm per year, in the subequatorial climate zone there is a relatively dry period - from August to October.
Brazil statistics
(as of 2012)
The Amazon River provides about 15% of the total annual flow of all rivers globe. Together with its tributaries, it forms a gigantic water system more than 25 thousand km long. The main channel of the Amazon is navigable for 4,300 km, and ocean-going ships rise 1,690 km from the mouth to Manaus.
To the east, the selva gradually gives way to rocky open forest (caatinga). Prickly and stinging subshrubs and all kinds of cacti are characteristic; dry-loving shrubs and trees, columnar cacti and tree-like euphorbias rise above them. Bottle trees are a landmark of Caatinga. During the winter-spring dry period, less than 10 mm of precipitation falls here per month at average temperatures of 26–28 °C. In autumn, heavy downpours bring 300 mm or more in one month, with an annual precipitation of 700–1000 mm. Precipitation is extremely uneven not only throughout the year, but also from year to year. Out of 100 years, 50 are characterized by either extreme drought or catastrophic floods, when rivers flood fields and buildings and remove the already thin layer of soil. Main river Caatinga - San Francisco. In the very center of the Brazilian plateau is the kingdom of shrubby and small-tree savannas and woodlands (campos cerrados). This is the main pastoral area of the country.
To the west, south of 17–18° south latitude, lie the vast plains of the upper Parana - the Parana Plateau. There are optimal conditions for growing coffee here: the average temperature of the coldest month is not lower than 14 °C, precipitation is about 1500 mm per year, and the dry period necessary for drying the beans is well defined, but not too sharp. Humus-rich lilac-red soils (“terra rocha”) are especially favorable for the coffee bush. To the south of 24° south latitude, extensive lava plateaus come directly to the surface. The ledges of hardened lava make all the left tributaries of the Parana “jump” down, as if on steps, forming numerous rapids and waterfalls. Iguazu Falls is especially famous.
Very special natural area Brazil - Pantanal (translated from Portuguese as "swampy area") - is located in the upper reaches of the Paraguay River, almost in the center of South America. This is a vast tectonic basin lying only 50–70 m above sea level. From the north, east and southeast it is sharply limited by the cliffs of the Brazilian Plateau. For many months, the Pantanal turns into a kind of lake-swamp. And in the winter drought it is a patchy landscape of never-drying, half-overgrown marshes, lakes and barely discernible wandering river beds, salt marshes, sandbanks and grassy areas. Birds are found here in abundance: storks, herons, ibises, cormorants, ducks, roseate spoonbill. Many people fly here for the winter from northern hemisphere. 38% of the country's territory is under forest. St. 20 nat. parks (Araguaia, Jau, Iguazu, Pico da Neblina, Tapajos, Xingu, etc.); nature reserves, sanctuaries.
Rivers and lakes of Brazil
Brazil's river network is very dense and rich in water. From west to east, the country is crossed by the deepest and largest river in the world, the Amazon, which irrigates northern regions countries. It is formed outside of Brazil by the confluence of the Marañon and Ucayali rivers and has a length of 6,400 km from the source of the Marañon, and more than 7,000 km from the source of the Ucayali. Its length within the country is 3165 km. The area of the Amazon basin in Brazil is about 4.8 million square meters. km (almost 60% total area pool). The width of its channel on the border with Peru is more than 1.5 km, in the middle reaches, near the city of Manaus - 5 km, in the lower reaches - up to 20 km, and at the mouth reaches 80-150 km. The depth of the river in the middle reaches is about 70 m, near the city of Obidus - 135 m, at the mouth - from 15 to 45 m.
Numerous tributaries flow into the Amazon. The largest right tributaries are the Purus (3 thousand km), Jurua, Tapajos and Xingu (each about 2 thousand km long), Madeira (about 1.5 thousand km). Large left tributaries are the Rio Negru (more than 1.5 thousand km), Zhapura, Isa. The Amazon mode is complex and varied. Due to the fact that its tributaries are located in different hemispheres, floods occur on them different time: on the right - from October to April (summer season in the southern hemisphere), on the left - from April to October (summer season in the northern hemisphere), and seasonal fluctuations in flow in the Amazon are smoothed out. The average water flow in the lower reaches is about 220 thousand cubic meters. m/sec. The average annual flow of the river is approximately 7,000 cubic meters. km - about 15% of the annual flow of all rivers on Earth. The Amazon carries an average of more than 1 billion tons of sediment per year. Its muddy yellow waters are visible in the ocean up to 300 km from the coast. The regime of the river is also influenced by sea tidal waves, which the Tupi Indians called “Amazunu”, hence the name of the river. These waves reach 5 m in height and travel up the river for 1400 km, flooding the low floodplains of the Igapo. The Amazon has significant energy potential (about 280 million kW), which is extremely underutilized.
The second largest river in South America, the Paraná, irrigates the south and southwest of Brazil (more than 1/10 of its territory). The main tributaries of the Paraná are the Paraguay, Tieteux, Iguazu, and Paranapanema. There are many rapids and waterfalls on the Parana and its tributaries. The largest of the waterfalls are: Iguazu (height about 80 m), located on the left tributary of the same name, and the cascade of waterfalls Seti-Kedas (Guaira) (33 m) on Parana. Paraná accounts for 57% of Brazil's vast hydroelectric potential, estimated at 79.4 billion kW. The eastern part of the country belongs to the basin of the San Francisco River (more than 2900 km long), in the lower reaches of which there is a cascade of Paulo Afonso waterfalls with a total height of 84 m. The rivers are characterized by sharp fluctuations in water flow. Other significant rivers in this area are Pa-raiba, Paraguaçu, Jequitinbna, etc. All of them are full-flowing, fast-moving and have great hydroelectric potential.
The largest rivers in the northeast of Brazil - Tocantins and Parnaiba - have rapids and are characterized by variable regime, which is also typical for other rivers in the region. During the dry season, some of them dry out. The rivers of the southeast are few in number and have the most stable regime, which is explained by the relatively uniform distribution of precipitation throughout the year. The constancy of the regime of these rivers is very important for the production of hydroelectric power. Most large river- Zhakuy. There are relatively few lakes in Brazil. These are mainly lagoon lakes and floodplain oxbow lakes, widespread in the Amazon floodplain. The largest of the lagoon lakes are the shallow lakes Patus (area exceeding 10 thousand sq. km) and Lagoa Mirin, connected by a channel.
Nature of Brazil
When the conversation turns to the nature of Brazil, the tropical Atlantic coast and the Amazon immediately come to mind. And this is not without reason: the endless forests, occupying more than half of the country’s territory, attract and delight. The vast expanses of Brazilian nature also contain an extraordinary diversity of flora and fauna. For example, out of 290 thousand plant species existing on Earth, 90 thousand grow in Latin America, mainly in Brazil. Scientists claim that of the 1 million 400 thousand species of animals existing on the planet, 10% again live in Brazil.
The Amazon is unique reserve fauna, and Panta-nal - an endless kingdom of swamps inhabited by a variety of animals - is translated into Russian as “swampy area”. Pantanal - a legacy of the Quaternary period, a vast tectonic depression, remnants of inland sea(which began to dry out 65 thousand years ago), bounded by the inaccessible mountain peaks of the Serra de Maracajou to the east, the Bolivian Chaco to the west and the Serra do Roncador to the north. This territory lies in the center of the mainland, and its area is equal to France, and the lands belong to two Brazilian states - Mato Grosso and Mato Grosso do Sul, Paraguay and Bolivia, but almost half of these vast territories lie within the borders of Brazil.
The Pantanal is characterized by a constant influx of water: streams, rivers, dams, lakes, interconnected, intersect, entangling the river channels. “No Man's Land” - this is how this area was rightly dubbed, a true kingdom of ornithologists and lovers wildlife who can observe here the life of birds, crocodiles, iguanas, jaguars, fallow deer, deer, otters, giant and dwarf ants, monkeys and tapirs. The waters that feed the Pantanal come down from the surrounding mountains. They also give life to the Paraguay River, which runs south to the Atlantic Ocean. This area, whose Brazilian center is the city of Cuiaba, located on the border of the Amazon and the Pantanal, can only be visited from April to September. At other times of the year, when the rainy season begins here, it is practically inaccessible: mountain streams turn into rivers, land into islands where animals find shelter.
Gradually, the swamps turn into forests, stretching from the northeast to Paraná, a state in southern Brazil. It was here, on the shores overgrown with impenetrable forest, that the first Portuguese conquistadors landed. Over the centuries, nature in Brazil has retreated under the onslaught of large cities, the first of which was São Paulo. Groves were planted that changed the bioclimate, for example, in the area of the Ara Cruz pulp mill in the state of Espiritu Saitu, where the planting of eucalyptus trees, from the wood of which paper is made, acquired a truly industrial scale. The area is characterized by endless forests, the flora and fauna of which are extremely diverse. The most common bird species are parrots, toucans and seagulls. One of the most untouched areas lying south of Sao Paulo is a forest area of 35 thousand square meters. km, declared a national park in 1958. Another is the Jureia mountain range, which means “protruding peak” in the Tupi-Guarani language, a huge mountain range that stretches to the coast of São Paulo. This is a real paradise with 40 km of pristine beaches.
400 species of medicinal plants grow here, a large number of animals and birds. And all this is located 200 km from the chaotic metropolis of São Paulo and 130 km from Cubatán, a city notorious for dumping toxic waste. industrial waste, which entailed genetic changes in the animal and flora district. Before these areas were declared a national reserve in 1987, they risked being wiped off the face of the Earth several times. In 1980, President Joao Bautista Figueiredo ordered the development of 236 square meters. km of area for the construction of a nuclear power plant. Fortunately, the work never began: the project did not find support, including financial support. Perhaps because of these precedents, it is impossible to visit the national park today: tourist excursions are prohibited, and only scientists and researchers can get here. Other areas, such as the Amazon, the Pantanal and Mata Atlantica, offer endless natural diversity thanks to the prevailing microclimate.
For example, flora National Park Serra Duquipo in the state of Minas Gerais is famous for having the maximum plant density per square meter. m. Scientists have recorded 1,600 of their species (and they believe that there is still room for research work), which bloom throughout the year, constantly changing the landscape. Heading down to the borders of Argentina, Rio Grande do Sul is home to the Torres Reefs, a famous resort area reminiscent of Dover in the UK. Near these giant rocks there are dolphins and sea lions, sailing into these waters every year, driven by the Antarctic winter. Much further south, in the state of Bahia, other giant marine mammals, whales, come ashore each year during mating season. They occupy the coastal waters of Abro-lus, giving birth and feeding their young here. The name Ab-rolhos comes from the phrase abra os olhos - “open your eyes”, invented by seafarers who were horrified by coral reefs, which they nicknamed cabecas - “heads” - suddenly growing out of the water 20-30 m and threatening to tear the sails . In 1983, the archipelago, consisting of several islands (Santa Barbara, Suesti, Redona and Guarita), was declared a National Marine Sanctuary. Other islands of the Brazilian coast acquired the same status: Fernando de Noronha and Trindade. They are not very popular among tourists: the tours are quite expensive.
Vegetation and soil of Brazil
More than half of Brazil's territory is covered by forests on red ferrallitic soils. The vegetation of Brazil is extremely rich and diverse and has about 50 thousand species (i.e. 1/4 of all species known to scientists). Humid equatorial evergreen forests, called gilea (in Brazil - selva), occupying the western part of the Amazon, are particularly rich in species composition, density, and multi-layered nature. They grow on red-yellow, often gleyed, ferrallite soils, which quickly lose structure and fertility when forests are cleared. Forest wealth and the species composition of Amazonian forests have not yet been sufficiently studied. There are more than 4 thousand species of tree species, of which 600 are of economic importance. Hundreds of palm species grow, with the tallest (up to 60 m) characteristic of the Varzea zone, which is flooded only during high floods. The following types of palm trees are common here: ivory, pashiuba, attalea and acai-euterna, from the fruits of which a popular refreshing and tonic drink and vegetable oil are prepared in the country, and a vegetable dish is prepared from the shoots. There are such valuable species trees like cotton (sumauma-ceiba), which produces silky kapok fiber; zedrela, which is a source of valuable wood; Copafeira, which supplies Copai balsam; cocoa tree and the most valuable of the rubber plants - seringueira, or hevea, whose homeland is the Amazon (now these plants are widespread on tropical plantations around the world). Ficus and strychnos grow here, containing the strongest of the poisons, “curare,” which the Indians used to poison their arrows.
Even richer and more diverse are the forests of the unflooded “solid land” - “terra firma”, or “ete”. It contains such valuable species of trees as mogno (mahogany-glowing) and caesalpinia (or pau-brazil, which gave the name to the country), which have red wood; “milk tree” - galactodendron with a sweet milky sap that tastes like milk; “melon tree” with edible fruits; castanya-bertolecia, which produces fruits rich in protein and oil, which are exported under the name “Brazil nuts” or “Para chestnuts”, etc. The trees are densely intertwined with vines and covered with epiphytes. The forests abound with flowers, especially orchids. Vegetation is also rich on the rivers of the Amazon.
One of the most famous aquatic plants is the giant water lily Victoria regia, the leaves of which reach a diameter of 2.5 m. To the east of the mouths of the Rio Negro and Madeira rivers, the gilea gradually turns into lighter deciduous evergreen forests, under which red ferrallitic soils are developed . The species composition of these forests is less rich than the composition of the Giles. They are characterized by a significant admixture of tall trees that shed their leaves during the dry season. There are many palm trees here, and above all the babasu species, which produce valuable nuts with a very high content of edible oil. There are open forests and areas of high-grass savannahs "Campos Gerais" with groups of palm trees: acai, Mauritius, inaja, etc. The "Varzea" and "Igapo" zones are characterized by evergreen vegetation on alluvial soils.
The southern border of the natural complexes of the Amazon is very unclear. As the relief increases to the southeast and the duration of the dry period increases, there is a gradual replacement of evergreen leafy forests by bottom evergreen and ferrallite-reddish-yellow soils by red ones. South of 5° S tropical rainforests stretch along the eastern edge of the Brazilian plateau and the Atlantic coast, which in the coastal part are largely reduced to plantations of tropical crops. The eastern windward slopes and high mountain plateaus of the Brazilian Plateau are characterized by pronounced altitudinal zonation. Tall-grass evergreen forests, similar in appearance and species composition to the Amazonian jungle, are common on the slopes. Higher up they give way to tree ferns and bamboos, and at an altitude of 1800 m deciduous trees and coniferous araucaria appear. Above 2200-2400 m, mountain meadows begin, giving way to peat bogs, mosses and lichens. The western leeward slopes of the eastern ridges of the highlands are characterized by seasonally wet deciduous forests. The central part of the Brazilian plateau is occupied by subequatorial open forest and shrub savanna (“campos cerrados”), formed on red coarse soils. During the rainy season, they are overgrown with turf-grass vegetation.
Deciduous low-growing trees and shrubs, growing here along with evergreens, are covered with small leaves with a waxy coating. Chaparro-curatella, licheira (“emery tree”), mangabey-ra, the milky juice and fruits of which are used as food by local residents, seem to have fruits very rich in vitamins, as well as agaves, cacti and some types of palms. During the dry period, everything burns out, and in some places a dense crust forms in the upper horizons of lateritic soils. In the west, the “Campos Cerrados” transition into the marshy low-lying Pantanal plain, which is flooded during the rainy season and during drought, which is a combination of swamps and lakes with areas of forests, shrubs and meadows. On the arid interior plains of the highlands, composed of porous sandstone and, in some places, clayey rocks, treeless grassy savannas (prairies), the so-called “campos-limpos” on reddish-black soils, are common, with gallery forests along river valleys. "Campos-Limpos" are beautiful pastures. The driest parts of Brazil - the interior of the northeastern part of the Brazilian Plateau - are covered with thickets of low-growing thorny bushes and cactus open forests ("caatinga") on thin, gravelly red-brown and red-brown soils. The “caatinga” is characterized by a bottle tree, the trunk of which contains a reserve of moisture accumulated by the tree during the rainy season; in the gallery forests along the river valleys grows the carnauba palm, the trunk and leaves of which are covered during the dry period with plant wax found wide application in technology and is an export item. Carnauba trunks are used as building material, and the leaves are widely used by local residents in everyday life for making mats, hats, baskets, roofs, etc. The oil palm babasu is also common here.
In the lower left-bank part of the Paraná River basin, dense tropical rainforests grow, which, as they rise along the eastern edge of the Brazilian Plateau, are gradually replaced by subtropical light coniferous forests of araucaria. The low-growing mate tree grows here in abundance, the leaves of which are used to prepare a tonic drink called Paraguayan tea, very popular in South American countries. These forests have been largely converted to coffee plantations. The humus lilac-red soils formed on lavas and the natural conditions of the area are extremely favorable for the cultivation of coffee bushes. In the south of the Brazilian Plateau, forests consisting only of araucaria are common. The extreme south of the country is occupied by treeless grassy humid subtropical savannas - “campos-limpos”. Almost the entire Atlantic coast of Brazil is bordered by a strip of mangroves.
Flora and fauna of Brazil
In the Amazon basin and along the Atlantic coast there is a tropical forest with luxurious broad-leaved trees. Much of central Brazil is covered with cerrado, a type of vegetation that consists of trees and shrubs with twisted branches, hard bark and dense leaves. The north-west of the country is dominated by caatinga, which is characterized by trees and shrubs that are drought-tolerant and have the ability to shed their leaves to retain moisture.
In the south are the Mata Araucaria pine forests, occupying the Southern Plateau. The plains, located at sea level, are covered with pastures. The wetlands of Mato Grosso, covering 230,000 sq km in the west-central part of the country, are covered with tall grass, weeds and trees. During the rainy season, the soil becomes flooded.
The Amazon jungle is the largest tropical forest in the world, covering an area of 5.5 million square meters. km., of which 60% are in the Brazilian states of Acre, Amazonas, Para, Mato Grosso and Maranhao. The remaining 40% covers the territory of both Guianas, Suriname, Venezuela, Colombia, Ecuador, Peru and Bolivia.
Of the twelve types of tropical mammals found in the Western Hemisphere, eleven are found in Brazil, numbering more than 600 species. This includes several species of the cat family such as spotted jaguar, and smaller ones - puma, sucuarana, jaguarundi and ocelot. Other mammals include: sloths, anteaters, tapirs, armadillos, dolphins, capivars and 30 species of monkeys.
The Toucan bird is practically the national calling card of this amazing country.
Brazil has the world's largest diversity of birds - 1,600 different types, including parrots. There are at least 40 species of turtles, 120 lizards, 230 snakes, 5 crocodiles, 331 amphibian species and 1,500 freshwater fish species. Biologists have cataloged about 100,000 species of invertebrates, 70,000 of which are insects.
In Brazil, there are about 3,000 species of fish in the lakes and rivers of the Amazon. Among the typical fish of the region, the following stand out: pirarucu (the largest freshwater fish in the world, some specimens of which reach 2 meters in length and 125 kilograms of weight); tambaci from the family of caracids, fruit eaters, whose teeth easily chew the seeds of the rubber tree and jauari palm; and finally piranha.
Geographical position
Geological structure
Natural areas and flora
Minerals
Bibliography
Geographical position
The Brazilian Plateau occupies most of eastern South America from 3 to 35° S. sh., mainly in Brazil, the south - in Uruguay, in the southwest its edge extends into Paraguay and Argentina. Strongly elevated in the east and southeast above the Atlantic coast. The highest point here above sea level is Pico da Bandeira, the highest peak of the Brazilian Plateau and Brazil. Height 2890 m (Fig. 1). It is located in the Caparao massif, between the lower reaches of the Paraiba and Rio Dosi rivers. Composed of gneisses. The slopes are covered with tropical rainforests. In the north to the Amazonian Lowland and in the southwest to the Laplata Lowland it is gently inclined; in the north-west it breaks off to the depression of the upper Paraguay.
Rice. 1 Pico da Bandeira
Geological structure
The Brazilian plateau consists of ancient crystalline shields and syneclises filled with sedimentary and volcanic rocks.
The ancient Guiano-Brazilian shield, which forms the basis of the Brazilian Plateau, is composed of Precambrian gneisses and crystalline schists, penetrated by granitoids. The shield protrudes to the surface in the form of the West Brazilian and East Brazilian protrusions of the folded basement. They are separated by the Parnaiba (Maranhao) and San Francisco basins. The East Brazilian high corresponds to the Late Proterozoic fold system (Baikalides), in places including older cores. At the beginning of the Cenozoic, the Cretaceous alignment surface here was uplifted, deformed and disrupted, which led to the formation of block mountains. The fault steps formed ledges. On the steep eastern side, they sometimes reach a height of several hundred meters and give the impression of real ridges (“serres”). From the foot of such a serra, the area to the east gradually rises, and then drops steeply down, forming a new serra.
The Brazilian plateau is low (from 250-300 to 800-900 m) and has a slightly hilly, almost flat topography. Even the highest outlier peaks are usually smoothed out. The eastern regional massifs reach the greatest heights. They form the Great Escarpment, descending in two large steps to the ocean. Among the ridges of the lower stage, Serra do Mar (1889 m) and Serra dos Organos (2070 m), located north of Gunabara Bay, stand out. Their proximity to Rio de Janeiro and Sao Paulo has made them a favorite holiday destination for wealthy Brazilians and tourists. The second, higher stage of the Great Escarpment is formed by the Serra do Mantiqueira, rising almost a full kilometer above the Serra do Mar. The highest peaks in Brazil are located here - Bandeira (Peak of the Banner), 2890 m and Agulhas Negras (Peak of the Black Eagles). Along the right bank of the river. In Sao Francisco, the sharp residual Proterozoic ridges of the Serra do Espinhaço rise to 1500-2100 m (Fig. 2). In a hot, humid climate, rocks are quickly destroyed: softer and looser ones are washed away by rainfall, while hard ones remain. Individual blocks acquired a cone-shaped shape, for which they received the name “sugarloaf” (Fig. 3). One of them adorns the picturesque bay of Rio de Janeiro. Syneclises (in the states of Maranhão and Piaui, along the rivers of São Francisco and the upper Paraná, etc.) are usually represented by stratified plains, often with erosional ledges of the cuesta type, and in the most elevated areas - remnant sandstone table plateaus with steep ledges - chapadas (they are characteristic and for a non-folded foundation cover); only the Parana depression is occupied by a stepped lava plateau.
Rice. 2 Residual Proterozoic Fig. 3 "sugarloaf" in the bay crests of Serra do Espinhaçu Rio De Janeiro
The further you go to the east, towards the humid breath of the Atlantic, the more the trees close together into a continuous cover of deciduous evergreen forests and the terrain becomes higher and rockier. The eastern edge of the Brazilian Plateau, which breaks down to the ocean, is already mountain ranges, broken into separate huge blocks, soaring steeply above tectonic depressions. The eastern edge of the Brazilian Plateau, which breaks down to the ocean, is already mountain ranges, broken into separate huge blocks, soaring steeply above tectonic depressions.
In the center and north-west, basement plateaus predominate, alternating with high plateaus - chapadas. To the west, the mountainous terrain gives way to the vast plains of the upper reaches of the Parana River - the Parana Plateau. Downstream of the Paraná there are extensive lava plateaus. The ledges of hardened lava make all the left tributaries of the Parana “jump” down, as if on steps, forming numerous rapids and waterfalls (Fig. 5). There are 56 of them on the Tieta River alone. Parana itself falls from a height of 17 m by the Senti Quedas waterfall (Fig. 4).
Rice. 4 Senti Kedas waterfall Fig. 5 waterfall of the left tributary of the Parana River
Natural areas and flora
The Brazilian plateau in the northwest and north is covered with moist evergreen and deciduous evergreen forests.
In the center are shrublands and savannas - campos cerrados, formed on red coarse soils. During the rainy season, they are overgrown with turf-grass vegetation. Campos plants are well adapted to the alternation of dry and wet seasons, which last about six months. Deciduous low-growing trees and shrubs, growing here along with evergreens, are covered with small leaves with a waxy coating. Chaparro-curatella, licheira (“emery tree”), mangabeira, the milky juice and fruits of which are used as food by local residents, seem to have fruits (Fig. 6), very rich in vitamins, as well as agaves, cacti and some types of palm trees.
Rice. 6 I show the fruits
During the dry period, everything burns out, and in some places a dense crust forms in the upper horizons of lateritic soils. In the west, the “Campos Cerrados” transition into the marshy, low-lying Pantanal plain, which is flooded during the rainy season and during drought, which is a combination of swamps and lakes with areas of forests, shrubs and meadows.
In the northeast there is xerophytic-succulent woodland - caatinga (Fig. 7).
Rice. 7 Caatinga (Portuguese caatinga, in the Tupi language - white, light forest)
Poor soils barely cover the rocks, and there is almost no grass. There are prickly shrubs and all kinds of cacti everywhere. And above them are dry-loving shrubs and trees, columnar cacti and tree-like euphorbia. At some distance from each other, like skittles, bottle trees grow (Fig. 8). These thickets are almost devoid of foliage and provide no shelter at all from the burning rays of the sun or from downpours. During the winter-spring dry period, which lasts 8-9 months, precipitation falls less than 10 mm per month. At the same time, the average air temperature is 26-28 C. At this time, many plants shed their leaves. Life freezes until the autumn rains, when more than 300 mm of precipitation falls per month with an annual amount of 700-1000 mm. As a result of rainfall, the water level in rivers rises rapidly. Floods occur regularly, destroying houses and washing away topsoil from fields.
In the east there are humid tropical evergreen and summer green forests. There, tropical rainforests stretch along the Atlantic coast, which in the coastal part are largely reduced to plantations of tropical crops. The eastern windward slopes and high mountain plateaus of the Brazilian Plateau are characterized by pronounced altitudinal zonation. Tall-grass evergreen forests, similar in appearance and species composition to the Amazonian jungle, are common on the slopes. Higher up they give way to tree ferns (Fig. 9, 10) and bamboos, and at an altitude of 1800 m deciduous trees and coniferous araucaria appear. Above 2200-2400 m, mountain meadows begin, giving way to peat bogs, mosses and lichens
In the south there are mixed coniferous forests with evergreen deciduous and treeless savanna - campos limpos; lateritic and chestnut soils are developed under the savannas. On the arid interior plains of the highlands, composed of porous sandstone and, in some places, clayey rocks, treeless grassy savannas (prairies) are common, with gallery forests along river valleys. "Campos-Limpos" are beautiful pastures.
The western leeward slopes of the eastern ridges of the highlands are characterized by seasonally wet deciduous forests.
Fig.8 Bottle tree
Rice. 9 tree ferns
Rice. 10 tree ferns
Climate
The Brazilian plateau lies in the subequatorial, tropical and subtropical climate zones. Average temperatures in January vary from southwest to northeast from 22 to 29 °C (maximum up to 42 °C), in July - from 12 to 25 °C, minimum - 6 °C (below the tropics). The amount and regime of precipitation within the Brazilian Plateau are very different: in the north and in the center precipitation falls mainly in summer, up to 1400-2000 mm per year (in the northeast less than 500 mm, the driest region), in the east - over 2000 mm, almost without drought, and in the south 1000-1800 mm throughout the year. The low mesas adjacent to the Amazon have a humid and hot tropical climate with heavy rainfall and thunderstorms. The climate is no less humid on the slopes of the Great Escarpment, facing the South Atlantic. The annual precipitation here is about 2000 mm. In the inland areas of the Brazilian Plateau, fenced off on all sides by high serras and chapadas, from 500 to 1000 mm of precipitation falls annually, with about 90% of it falling during the rainy season (January - June). But even at this time, cruel, devastating downpours only wash the earth. The moisture evaporates before the soil has a chance to absorb it. It is not uncommon for the dry season to last throughout the year, causing severe droughts.
Loading...
