Chapter 10 Topic A General Introduction And Physical Environment Of South America Long Answer Questions
Question 1. Discuss the geographical location and size of South America.
Answer: The geographical location and size of South America are discussed below-
Geographical location:
South America lies to the south of the North. America is surrounded by the Atlantic Ocean in the east, the Pacific Ocean in the west and the Antarctic Ocean in the south.
Class 8 Geography WBBSE
The continent has a triangular shape. The location of South America can be discussed under the following heads-
1. Latitudinal:
South America extends from 12°28′ N to 55°59′ S. This implies that the Equator (0°) and the Tropic of Capricorn (23°30’S) pass through the continent.
2. Longitudinal:
South America extends from 34°50′ W in the east to 81°20′ W in the west.
3. Hemisphere:
About 85 per cent of the continent lies in the southern hemisphere. South America is often referred to as a continent of the southern hemisphere.
4. Boundaries:
This continent is flanked by seas And oceans-Panama Canal and the Caribbean Sea in the north, the Pacific Ocean in the west, the Atlantic Ocean in the east and the Antarctic Ocean in the south.
Size:
WBBSE Class 8 South America Physical Environment
In terms of size, South America is the fourth largest continent in the world (17,840,000 sq. km area). South America is about twice the size of Europe and five times that of India.
Question 2. Give a brief description of the topography of South America.
Answer:
Topography Of South America:-
The topography of South America is classified into four categories based on the features of the landforms-
- The Western Mountain Region,
- Narrow Coastal Plains of the west,
- Eastern Highland Region,
- The extensive Central Plain.
1. The Western Mountain Region:
The mountain region in the west of South America covers the Andes Mountain ranges. The Andes Range is the longest Coastal Plain of a continuous chain of mountains in the world. It extends from Panama in the north to Cape Horn in the south.
It is the second-highest mountain range in the world. The Andes is a chain of young fold mountains and hence is geologically active. This leads to frequent earthquakes and volcanic eruptions.
The entire region of the Andes is part of the Pacific Ring of Fire: Mt. Chimborazo (6272 m) and Cotopaxi (5896 m) are the first and second highest active volcanoes on Earth respectively.
The highest mountain peak in the Andes is the Aconcagua (6960m). World’s highest lake, Titicaca (3810m) is located in this area.
2. Narrow Coastal Plains of the West:
Besides the Central Plains, there are narrow stretches of plain lands lying along the western, eastern and northern coasts of South America. In the western part, the Andes descend abruptly into the ocean.
WBBSE Class 8 Geography Long Answer Questions
Thus, it can be said that the coastlines barely exist here. Atacama desert, about 1100 km long lies in the middle of this region. This is one of the most driest and drought-prone areas of the world.
On the other hand, the coastal plains are quite extensive in the eastern as well as the northern parts, near the Amazon and the La Plata river basins.
3. Eastern Highland Region:
The Eastern Highlands consist of the Guiana Highlands (average height 800 m) in the north, the Brazilian Highlands (average height 1000m) in the east and the Patagonian Plateau region in the south.
The Amazon separates the Guiana Highlands from the Brazilian Highlands. The Mato Grosso plateau exists between Brazilian Highlands and the Andes.
This area acts as a watershed between Amazon and La Plata rivers. The Angel Falls in Venezuela is in the Guiana Highlands. It is the world’s highest waterfall (979 m) and is situated on a tributary of the river Orinoco.
Roraima (2769 m) is the highest peak of the Guiana Highlands. The Brazilian Highlands extend over a larger area and are higher than the Guiana Highlands. The Brazilian Highlands cover the eastern part of South America.
The central parts of the Brazilian Highlands are occupied by the Campos grasslands. Pico-da-Banderia is the highest peak of this region located along the coastal zone of the Atlantic Ocean in the south-eastern margin of this highland.
The rivers San Francisco and the Parana flow through these highlands. The Patagonian Plateau is situated close to the southern part of the Andes and the western part of Argentina. This region gradually slopes down to the Atlantic Ocean.
The climatic condition in the plateau region is arid. Patagonia is a large cold desert and experiences an average temperature of 3°C.
4. The extensive Central Plain:
These plains consist of three large river basins-the Orinoco river basin, the Amazon river basin and the La Plata river basin. The Central Plains refer to the vast stretch of plainland that lies between the Andes and the Eastern Highlands.
The Orinoco river originates in the Guiana Highlands and after travelling through Venezuela and Colombia, meets the Atlantic Ocean. The Orinoco River basin covers the northern region of South America.
Physical Features of South America for Class 8
Question Answer
The World’s largest river in terms of water discharge, is the Amazon. The rainforest formed along the Amazon River basin is the largest in the world.
The Amazon originates in the Andes and after travelling through Peru, Ecuador, Colombia and Brazil, it drains into the Atlantic Ocean. The La Plata basin consists of three major rivers-the Parana, Paraguay and Uruguay.
These rivers originate in the Brazilian Highlands and join the Atlantic Ocean. The river basin is in the southern part of the continent.
Question 3. What are the major rivers in South America? Give a brief account of these rivers.
Answer:
Rivers of South America:
The major rivers in South America are the Amazon, the Orinoco, the La Plata and the Sao Francisco. Most of the rivers in South America originate either in the Mato Grosso Plateau region or in the western parts of the Andes and then flow into the Atlantic Ocean in the east.
Overview of the rivers of South America:
An overview of the rivers is given below-
Question 4. Describe the topography of the northern and eastern highlands or plateaus.
Answer:
Topography of the Highland:
The plateaus that extend over a considerable area in the north of South America are of residual type. Various forms of erosion over the years have led to a reduction in the height of these plateaus.
The plateau region that stretches across Venezuela, Guyana, Surinam, French Guiana and Brazil are called the Guiana Highlands.
However, since these highlands rise to considerable heights in Venezuela, some mountain ranges have also developed here. Roraima (2769 m) is the highest peak in this upland.
Class 8 Geography South America Topic A Solutions
Topography of the Eastern Highland:
The eastern highlands of South America are called the Brazilian Highlands, while the central highlands are called the Mato Grosso Plateau region. This plateau actually connects the Brazilian Highlands in the east with the Andes in the west.
The sharp edges of the Brazilian Highlands abruptly descend to the Atlantic Ocean in the east. On the other hand, in the west, these highlands gradually become sloping and blend with the central plain lands.
A major area of the Brazilian Highlands is occupied by the Campos grassland. The average elevation of the highlands is 1000 metres and the highest mountain peak in this region is this Pico-da-Bandeira.
Question 5. What are the determinants of the climatic diversity prevailing in South America? Or, Discuss the factors affecting the climatic characteristics of South America.
Answer: The main determinants of the climatic characteristics of South America are-
1. Shape of the continent:
The continent has a wide and extensive northern part and a southern part that gradually tapers. So, South America appears triangular in shape. That is why no maritime effects are seen in the interior of the northern parts of this continent.
Most of South America lies to the south of the equator, while a considerably small part in the north of the continent lies to the north of the equator.
As a result, the northern and the southern parts of South America experience opposite seasons during the same time.
2. Latitudinal extent:
The maximum portion of South America is in the tropical zone because it extends from 55°59′ S to 12°28′ N latitudes. The areas in the equatorial zone experience is extremely hot climates.
However, places located at high latitudes in the southern hemisphere experience comparatively cooler climates.
3. Distance from the sea:
The southern part of the continent is narrow. Some regions in this part are only 250 km away from the sea. Hence, these regions experience a maritime climate (moderate).
On the other hand, the regions in the north experience a continental type of climate (extreme) because of their huge distance from the sea.
4. Effect of the Equator and the Tropic of Capricorn:
The equator passes through the Amazon river basin in the north, which causes an equatorial type of climates to prevail in these regions. On the other hand, the Tropic of Capricorn passes through the central part of the southern region.
This leads to hot tropical climate in the north and cool temperate climate in the south. Actually, 70% area of this continent lies in the torrid zone, 20% in the warm temperate zone and 10% in the cold temperate zone.
Understanding South America’s Physical Environment
5. Location of the Andes:
The Andes mountain range occupies the western part of South America and it extends from the north to south in a long, continuous chain.
The Andes acts as a barrier to the moist winds, as a result of which very little rainfall is experienced on the leeward side of the mountain. This leads to the formation of a rainshadow region here.
6. Ocean currents:
The cold Humboldt Current or the Peru Current that moves across the southwestern coast leads to a cold and dry climate in these regions.
Similarly, the warm Brazil Current that moves along the eastern coast leads to the development of hot and humid climate in these regions.
7. Constant flow of trade winds:
The northeast trade winds blowing from the north and the southeast trade winds blowing from the south lead to heavy rainfall in these regions throughout the year. The northwest westerlies also cause heavy rainfall in the southern parts of Chile.
8. Elevation of land:
The higher regions of the Andes experience a pleasant and cool climate due to their high altitude. The Brazilian and the Guiana Highlands also experience cool climates due to their comparatively high altitudes, in spite of being located in the torrid zone.
Detailed Study of South America’s Geography
Question 6. Write about the various climatic regions of South America.
Answer:
Various Climatic Regions Of South America:-
The climatic regions of South America can be classified into the following nine categories based on temperature, rainfall, air pressure, etc. These are discussed in the following table-
Question 7. Write about the characteristic features of the topography and rivers of the Amazon river basin.
Answer:
Characteristic features topography of the Amazon River basin:
The topographic characteristics of the Amazon River basin are as follows-
- The central region of the Amazon River basin is almost plain.
- From this central region, the land has gradually elevated in three sides-the Guiana Highlands in the north, the Brazilian Highlands in the south and the Andes mountain range in the west.
- The river does not form any delta at its mouth and flows uninterruptedly towards the east into the Atlantic Ocean. Hence, the shape of the river basin is like a funnel.
- This region naturally slopes from west to east.
- The river basin has developed as a result of silt deposition by the Amazon and its tributaries.
- The Amazon has a wide mouth and some islands have developed there. Among these, Marajo is the largest fluvial island in the world.
- The Amazon River basin consists of flood plains, ox-bow lakes, swamps and islands.
Characteristic features of the rivers of the Amazon basin:
WBBSE Class 8 Geography South America Notes
The characteristic features of the rivers of the Amazon River basin are as follows-
1. Amazon:
The Amazon is the largest river in the world, in terms of the volume of water it carries and the area of the river basin. It is the longest river in South America.
It originates in the Mismi mountain peak in the Andes. Then it travels first across the north and then across the east to join the Atlantic Ocean. The Amazon River basin is located in the equatorial region that receives heavy rainfall.
So, a large volume of rainwater, collected by several tributaries, gets accumulated in the Amazon river. From the origin to the mouth, the length of the river is 6437 km.
The left bank tributaries of the river are-Napo, Negro, Japure, etc., and the right bank tributaries are Jurua, Purus, Madeira, Tapajos, Xingu, etc.
2. Other rivers:
Most of the other rivers that flow through the Amazon River basin are its tributaries. Among these, the main rivers are Madeira, Tapajos, Xingu, Jurua, Negro, Japura, etc.
The Madeira (3250 km) carries a large volume of water and discharges into the Amazon. It is the largest tributary of the Amazon River.