MOUNTAINS

MOUNTAINS

Broadly, we can group different landforms depending on elevation and slope as mountains, plateaus, and plains.

A hill is a land surface that rises higher than the surrounding area. Generally, a steep hill with an elevation of more than 600 meters is termed as a mountain. A mountain is any natural elevation of the earth's surface. The mountains may have a small summit and a broad base. It is considerably higher than in the surrounding area. Some mountains are even higher than the clouds. As you go higher, the climate becomes colder.

In some mountains, there are permanently frozen rivers of ice. They are called glaciers. There are some mountains you cannot see as they are under the sea. Because of the harsh climate, fewer people live in mountain areas. Since the slopes are steep, less land is available for farming.

Mountains may be arranged in a line known as the range. Many mountain systems consist of a series of parallel ranges extending over hundreds of kilometers. The

Himalayas, the Alps, and the Andes are mountain ranges of Asia, Europe, and South America, respectively (Figure 5.1). Mountains vary in their heights and shape. 

There are three types of mountains - Fold Mountains, Block Mountains, and the Volcanic Mountains.

Fold Mountains

The Himalayan Mountains and the Alps are young fold mountains with rugged relief and high conical peaks. The Aravali range in India is one of the oldest fold mountain systems in the world. The range has considerably worn down due to the processes of erosion. The Appala chians in North America and the Ural mountains in Russia have rounded features and low elevation. They are very old fold mountains.

Block Mountains

Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. The Rhine valley and the Vosges mountain in Europe are examples of such mountain systems.

Locate them on the world map in the atlas and find out some more examples of this type of landform.

Volcanic Mountains.

Volcanic mountains are formed due to volcanic activity. Mt.Kilimanjaro in Africa and Mt.Fujiyama in Japan are examples of such mountains.

Mountains are very useful. The mountains are a storehouse of water. Many rivers have their source in the glaciers in the mountains. Reservoirs are made and the water is harnessed for the use of people. Water from the mountains is also used for irrigation and the generation of hydro-electricity. The river valleys and terraces are ideal for the cultivation of crops. Mountains have a rich variety of flora and fauna. The forests provide fuel, fodder, shelter, and other products like gum, raisins, etc. Mountains provide an idyllic site for tourists. They visit the mountains for their scenic beauty. Several sports like paragliding, hang gliding, river rafting and skiing are popular in the mountains. Can you name some places in the Himalayas associated with these sports?

Do you know?

Mauna Kea (Hawaii) in the Pacific Ocean is an undersea mountain. It is higher than Mount Everest being 10,205 meters high. Name some mountains with a height of

more than 8,000 meters.

Activity:

Let’s Do

Making of a Mountain:

1.All you require is a pile of paper.

2.Put the papers on your table.

3.Push the papers from both sides by your hands.

4.The sheet will be folded and rise to a peak.

You have made a mountain. In the same process, our Himalayas and the Alps were formed!

Source: This Topic is taken from NCERT TEXTBOOK.

PLATEAUS

PLATEAUS

A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area. A plateau may have one or more sides with steep slopes. The height of plateaus often varies from a few hundred meters to several thousand meters. Plateaus, like mountains, may be young or old. The Deccan plateau in India is one of the oldest plateaus. The East African Plateau in Kenya, Tanzania, and Uganda, and the Western plateau of Australia are other examples. The Tibet plateau is the highest plateau in the world with a height of 4,000 to 6,000 meters above the mean sea level.

Plateaus are very useful because they are rich in mineral deposits. As a result, many of the mining areas in the world are located in the plateau areas. The African plateau is famous for gold and diamond mining. In India, huge reserves of iron, coal, and manganese are found in the Chhotanagpur plateau.

In the plateau areas, there may be several waterfalls as the river falls from a great height. In India, the Hundru falls in the Chhotanagpur plateau on the river Subarnarekha and the Jog falls in Karnataka are examples of such waterfalls. The lava plateaus are rich in black soil that are fertile and good for cultivation. Many plateaus have scenic spots and are of great attraction to tourists.

Source: This Topic is taken from NCERT TEXTBOOK.

PLAINS

PLAINS

Plains are large stretches of flat land. They are, generally, not more than 200 meters above mean sea level. Some plains are extremely level. Others may be slightly rolling and undulating. Most of the plains are formed by rivers and their tributaries. The rivers flow down the slopes of mountains and erode them. They carry forward the eroded material. Then they deposit their load consisting of stones, sand, and silt along with their courses and in their valleys. It is from these deposits that plains are formed.

Generally, plains are very fertile. Construction of the transport network is easy. Thus, these plains are very thickly-populated regions of the world. Some of the largest plains made by the rivers are found in Asia and North America. For example, in Asia, these plains are formed by the Ganga and the Brahmaputra in India and the Yangtze in China.

Plains are the most useful areas for human habitation. There is a great concentration of people as more flat land is available for building houses, as well as for cultivation. Because of fertile soil, the land is highly productive for cultivation. In India too, the Indo-Gangetic plains are the most densely populated regions of the country.

Source: This Topic is taken from NCERT TEXTBOOK.