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Q. What
is Glacier? Explain the various types of Glacier on the basis of location or
area of origin.
A glacier is a persistent body of dense ice that is
constantly moving under its own weight. A glacier forms where the accumulation
of snow exceeds its ablation over many years, often centuries.
- Continental Glaciers: A thick ice sheet covering vast area of land is called a continental glacier. The thickness of ice in such regions goes upto thousands of metres. Glaciers of this type build up at the centre and move outward in all directions. Continental glaciers of today are found mainly in Antarctica and Greenland. The precipitation in these regions occurs in the form of snow.
- Valley Glaciers: When a mass of ice from the high mountainous regions starts moving down into the pre-existing valleys, it is called a valley glacier or a mountain glacier. The shape of the valley glaciers depends on the valley it occupies. Where the valley is broad, the glacier spreads outwards and where the valley is narrow, the glacier contracts.
Q. What
do you mean by Plateau? Explain the economic significance of Plateau.
A plateau is an elevated area of more or less level land on
its top. It has a large area on its top and steep slope on its side.
- Storehouse of Minerals: Most of the minerals in the world are found in the plateaus. Besides, the extraction of minerals is relatively easier on plateaus. These minerals are indispensable as raw material for our industries. We get gold from the Plateau of Western Australia; copper, diamonds and gold from the Plateaus of Africa and coal, iron, manganese and mica from the Chota Nagpur Plateau in India.
- Generation of Hydel-power: Rivers falling down the edges of plateaus form water-falls. These waterfalls provide ideal sites for generating hydel-power.
- Cool Climate: Plateaus have large grassland areas suitable for animal-rearing specially sheep, goat and cattle. They provide a veriety of products such as wool, milk, meat and hides and skin. The lava plateaus as compared to all other plateau are richer in agriculture since their soil is very fertile.
Q. What
do you mean by Plains? Explain the economic significance of Plains.
Plains are the most important landforms found on the earth’s
surface. A low lying relatively flat or slightly rolling land surface with very
gentle slope and minimum local relief is called a plain.
Economic Significance of Plains
- Fertile Soil: The plains generally have deep and fertile soil. Since the plains have a flat surface, the means of irrigation are easily developed. Both these factors have made the plains agriculturally so important that they are often called ‘food baskets of the world’.
- Growth of Industries: The rich agricultural resources especially of alluvial plains have helped in the growth of agro based industries. This has given employment to millions of people and has registered a marked increase in the national production and per capita income. Since the plains are thickly populated, plenty of labour is available for the intensive cultivation and for supplying work force for industries.
- Expansion of Means of Transport: Since the plains have an even surface it favours the building of roads, airports and laying down of railway lines.
- Centres of civilization: The plains have been the centres of many modern and ancient civilizations. The major river valley civilizations of the world have flourished in the plains only. Hencs, they are aptly referred to as the cradles of civilization. For example, there are the civilization of the Indus and the Nile Valley.
- Setting-up of Cities and Towns: Easy means of transport on land, the growth of agriculture and industries in plains have resulted in the setting-up and expansion of cities and towns. The most developed trade-centres and ports of the world are found in the plains only. Rome, Tokyo, Calcutta, Yangoon (Rangoon), Varanasi, Paris and other famous cities are situated in the plains.
Q. What
do you mean by ‘food baskets of the world’?
The plains generally have deep and fertile soil. Since the
plains have a flat surface, the means of irrigation are easily developed. Both
these factors have made the plains agriculturally so important that they are
often called ‘food baskets of the world’.
Q. Explain the economic significance of Mountain.
- Storehouse of Resources: Mountains are the storehouse of natural resources. Large resources of minerals are found in mountains. The Appalachian range in the United States is well-known for coal and limestone deposits. We get timber, lac, medicinal herbs and wood for making pulp from the forests of the mountains.
- Generation of Hydro-electricity: Hydro-electricity is generated from the waters of perennial rivers in the mountain regions. The mountainous countries like Japan, Italy and Switzerland, which suffer from the shortage of coal have developed hydro-electricity.
- Abundant Sources of Water: Perennial rivers rising in the snow fed or heavily rain fed mountains are the important source of water. They help in promoting the irrigation and provide water for many other uses.
- Formation of Fertile Plains: The rivers that originate in the high mountain region bring silt along with water to the lower valleys. This helps in the formation of fertile plains. The great alluvial plain of northern India has been formed by the rivers Ganga, Sutlej and the Brahmaputra.
- Natural Political Frontiers: The mountain ranges do act as natural political frontiers between countries and protect them from invasions to some extent. The Himalaya have formed a political frontier between India and China.
- Effect on Climate: Mountainous areas have lower temperatures. They serve as climatic divide between two adjoining regions. The Himalaya for example form a barrier to the movement of cold winds from Central Asia towards the Indian subcontinent.
- Tourist Centres: The pleasant climate and the beautiful scenery of the mountains have led to their development as centres of tourist attraction. The tourist and hotel industries get an additional encouragement in such regions. Shimla, Nainital, Mussorie and Srinagar are some of the important hill stations of India which attract tourists all over the world.
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