NCERT Book Class 6 Civics Major Landforms Of The Earth

Chapter 6

MAJOR LANDFORMS OF THE EARTH

You must have seen some of the landform features as shown in the Figure 6.1 below. You will notice that the surface of the earth is not the same everywhere. The earth has an infinite variety of landforms. Some parts of the lithosphere may be rugged and some flat. These landforms are a result of two processes. You will be amazed to know that the ground you are standing on is slowly moving. Within the earth, a continuous movement is taking place. The first, or the internal process leads to the upliftment and sinking of the earth’s surface at several places.

The second, or the external process is the continuous wearing down and rebuilding of the land surface. The wearing away of the earth’s surface is called erosion. The surface is being lowered by the process of erosion and rebuilt by the process of deposition. These two processes are carried out by running water, ice and wind. Broadly, we can group different landforms depending on elevation and slope as mountains, plateaus and plains.

MOUNTAINS

A mountain is any natural elevation of the earth surface. The mountains may have a small summit and a broad base. It is considerably higher than 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 frozenrivers of ice. They are called glaciers. There are some mountains you cannot see as they are under the sea.

Because of harsh climate, less people live in the mountain areas. Since the slopes are steep, less land is available for farming. Mountains may be arranged in a line known as range. Many mountain systems consist of a series of parallel ranges extending over hundreds of kilometres. 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. 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 Appalachians in North America and the Ural mountains in Russia (Figure 5.1) have rounded features and low elevation. They are very old fold 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 landforms. 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 generation of hydro-electricity. The river valleys and terraces are ideal for 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?

EXERCISE

1. Answer the following questions briefly.

(a) What are the major landforms?

(b) What is the difference between a mountain and a plateau?

(c) What are the different types of mountains?

(d) How are mountains useful to man?

(e) How are plains formed?

(f) Why are the river plains thickly populated?

(g) Why are mountains thinly populated?

2. Tick the correct answers.

(a) The mountains differ from the hills in terms of

(i) elevation    (ii) slope    (iii) aspect

(b) Glaciers are found in

(i) the mountains    (ii) the plains    (iii) the plateaus

(c) The Deccan Plateau is located in

(i) Kenya    (ii) Australia     (iii) India

(d) The river Yangtze flows in

(i) the South America     (ii) Australia    (iii) China

(e) An important mountain range of Europe is

(i) the Andes    (ii) the Alps     (iii) the Rockies

Please refer to attached file for NCERT Class 6 Civics Major Landforms Of The Earth