Topic outline

    • Physical Features of India

      Q49. Which are the major physiographic divisions of India? Contrast the relief of the Himalayan region with that of the Peninsular plateau.

      Ans. The physical features of India can be grouped under the following physiographic divisions

      (1) The Himalayan Mountains

      (2) The Northern Plains

      (3) The Peninsular Plateau

      (4) The Indian Desert

      (5) The Coastal Plains

      (6) The Islands

       

      Himalayan region

      Peninsular plateau

      1. The Himalayas, geologically young and structurally fold mountains stretch over the northern borders of India.

      1. Peninsular Plateau constitutes one of the ancient landmasses on the earth’s surface.

      2. It was formed due to collision of the Indo-Australian plate and Eurasian Plate.

      2. It was formed due to the breaking and drifting of the Gondwana land.

      3. The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world.

      3. The plateau has broad and shallow valleys and rounded hills.

      4. It is composed of sedimentary rocks.

      4. It is composed of igneous and metamorphic rocks with gently rising hills and wide valleys.

      5. From the view point of geology, Himalayan mountains form an unstable zone.

      5. It is a stable zone.

       

      Q50. Distinguish between
      (i) Converging and diverging tectonic plates
      (ii) Bhangar and Khadar
      (iii) Western Ghats and Eastern Ghats

      Ans. (i) Converging and diverging tectonic plates

      Converging tectonic plates

      diverging tectonic plates

      1. The tectonic plates move closer to each other and form convergent boundary.

      1. The tectonic plates move away from each other and form divergent boundary.

      2. The two plates coming together may either collide and crumble, or one may slide under the other. At times, they may also move horizontally past each other and form transform boundary.

      2. The two plates drift away from each other, creating gap between the two.

      3. Convergence of plates may result into activities like earthquake.

      3. Divergence of plates may result into volcanic eruption.

      4. Formation of Himalayas is a result of convergence of tectonic plates.

      4. Formation of Great Atlantic Drift is a result of divergence of plates.

       

      (ii) Bhangar and Khadar

      Bhangar

      Khadar

      1. The largest part of the northern plain is formed of older alluvium. They lie above the flood plains of the rivers and present a terrace like feature. This part is known as bhangar.

      1. The newer, younger deposits of the flood plains are called khadar.

      2. The soil in this region contains calcareous deposits locally known as kankar. This soil is less fertile.

      2. They are renewed almost every year and so are fertile, thus, ideal for intensive agriculture.

       

      (iii) Western Ghats and Eastern Ghats

      Western Ghats

      Eastern Ghats

      1. The Western Ghats mark the western edges of the Deccan Plateau.

      1. The Eastern Ghats mark the eastern edges of the Deccan Plateau.

      2. Western Ghats lie parallel to the western coast. They are continuous and can be crossed through passes only.

      2. The Eastern Ghats are discontinuous and irregular and dissected by rivers draining into the Bay of Bengal.

      3. The Western Ghats are higher than the Eastern Ghats.

      3. The Eastern Ghats are lower than the Western Ghats.

      4. Their average elevation is 900–1600 metres.

      4. Their average elevation is 600 metres.

      5. The highest peaks in the Western Ghats are Anai Mudi and the Doda Betta.

      The highest peak in the Eastern Ghats is Mahendragiri.

       

      Q51. Write short notes on the following.
      (i) The Indian Desert
      (ii) The Central Highlands
      (iii) The Island groups of India

      Ans. (i) The Indian Desert

      Characteristics of Indian desert:

                              i.        The Indian desert lies towards the western margins of the Aravali Hills.

                             ii.        It is an undulating sandy plain covered with sand dunes.

                            iii.        This region receives very low rainfall below 150 mm per year.

                            iv.        It has arid climate with low vegetation cover.

                             v.        Streams appear during the rainy season.

                            vi.        Luni is the only large river in this region.

               vii.        Barchans (crescent shaped dunes) cover larger areas but longitudinal dunes become more prominent near the Indo-Pakistan boundary.

       

      (ii) The Central Highlands

      The part of the Peninsular plateau lying to the north of the Narmada river covering a major area of the Malwa plateau is known as the Central Highlands. The Vindhyan range is bounded by the Central Highlands on the south and the Aravalis on the northwest. The further westward extension gradually merges with the sandy and rocky desert of Rajasthan. The flow of the rivers draining this region, namely the Chambal, the Sind, the Betwa and

      Ken is from southwest to northeast, thus indicating the slope. The Central Highlands are wider in the west but narrower in the east. The eastward extensions of this plateau are locally known as the Bundelkhand and Baghelkhand. The Chotanagpur plateau marks the further eastward extension, drained by the Damodar river.

       

      (iii) The Island groups of India

      Lakshadweep Islands

      Lakshadweep Islands group lying close to the Malabar coast of Kerala. This group of islands is composed of small coral isalnds. It covers small area of 32 sq km. Kavaratti island is the administrative headquarters of Lakshadweep. This island group has great diversity of flora and fauna. The Pitti island, which is uninhabited, has a bird sanctuary.

      Andaman and Nicobar islands

      The elongated chains of islands located in the Bay of Bengal extending from north to south are called Andaman and Nicobar islands. The entire group of islands is divided into two broad categories – The Andaman in the north and the Nicobar in the south. It is believed that these islands are an elevated portion of submarine mountains. These island groups are of great strategic importance for the country. There is great diversity of flora and fauna in this group of islands too. These islands lie close to equator and experience equatorial climate and has thick forest cover.