Key Concepts - Physical Features of India Notes | Study Social Studies (SST) Class 9 - Class 9

Location

1. India has all major physical features of the Earth, i.e. mountains, plains, deserts, plateaus and islands.
2. In India the soil color varies from place to place as it is formed from different types of rocks.
3. India has varied physical features whose formation can be explained on the basis of the ‘Theory of Plate Tectonics’.
4. According to the theory of Plate Tectonics the seven major and minor plates that form the Earth’s crust keep moving, causing stress and thus leading to folding, faulting and volcanic activity.
5. The physical features of India can be grouped under the following physiographic divisions :
   (i) The Himalayan Mountains.
   (ii) The Northern Plains
   (iii) The Peninsular Plateau
   (iv) The Indian Desert
   (v) The Coastal Plains
   (vi) The Islands

Fig. Physiographic divisions of India

The Himalayan Mountains

1. The Himalayas are young-fold mountains which are the loftiest and one of the most rugged mountain barriers of the world.
2. The Himalayas are 2400 km long, 400 km to 150 km wide from Kashmir to Arunachal Pradesh respectively.
3. The Himalayas have three parallel ranges in the longitudinal extent namely :
   — Great or Inner Himalayas also called Himadri.
   — Middle Himalayas or Himachal.
   — Outer Himalayas or Shivalik.
4. The Himalayas can be divided into four sections :
   — Punjab Himalayas — between Indus and Satluj.
   — Kumaon Himalayas — between Satluj and Kali.
   — Nepal Himalayas — between Kali and the Tista.
   — Assam Himalayas (Eastern Himalayas) — Between Tista and the Dibang (Tsangpo). 

Fig. Himalayas

The Northern Plains

1. The Northern Plains spread over an area of 7 lakh sq. km, 240 km long and 240 km to 320 km broad.
2. The rivers that flow to the plains from the mountains are involved in depositional work.
3. Difference in relief causes the Northern Plain to have four regions.
   — Bhabar — laying at the foot of Shivalik, a narrow 8 to 16 km wide belt of pebbles.
   — Terai — lying next to Bhabar, a wet and marshy area with wildlife and forests.
   — Bangar — Older alluvium plain which rises above the level of the flood plains.
   — Khadar — Younger alluvium of the flood plains.

The Peninsular Plateau

1. The Peninsular Plateau is the tableland formed due to the breaking and drifting of the Gondwanaland.
2. The plateau consists of two broad divisions, namely, the Central Highlands and the Deccan Plateau.
3. The eastward extensions of Peninsular Plateau are locally known as Bundelkhand and Baghelkhand. The Chhota Nagpur Plateau marks the further eastward extension drained by the Damodar river.
4. The Deccan Plateau, a triangular mass, lies to the south of the river Narmada.
5. The western and eastern edges of the Deccan Plateau are marked by the Western Ghats and the Eastern Ghats respectively.
6. The Western Ghats are higher than the Eastern Ghats.
7. A distinct feature of the peninsular plateau is the black soil area known as Deccan Trap.

The Indian Desert

1. The undulating sandy plain covered with sand dunes towards the western margins of the Aravalli Hills is the Indian Desert.
2. Crescent shaped dunes called barchans cover large parts of the Indian Desert.
3. Luni is the only large river in this region.

Fig. Indian Desert

 The Coastal Plains

1. The narrow coastal strips flank the Peninsular Plateau.
2. On the west the coastal strips are divided into Konkan (Mumbai-Goa), Kannad Plain and the Malabar coast from northern to southern part.
3. On the east the coastal strip is divided into Northern Circars and the Coromandal Coast from northern to southern part.

The IslandsFig. Islands

1. The Lakshadweep Islands group in the Arabian Sea is close to Kerala.
2. The Lakshadweep Islands were formerly known as Laccadive, Minicoy and Amindive.
3. The Andaman and Nicobar Islands are an elongated chain of islands located in the Bay of Bengal.
4. The Andamans and Nicobar Islands are an elevated portion of submarine mountains.