Ch- physical features of India

1. what do you mean by the theory of plate tectonics?

Ans  Earth scientists have explained the formation of physical features with the help of some theories and one such theory is the ‘Theory of plate tectonics’  according to this theory , the crust of the earth has been formed out of seven major and some minor plates . The movement of these plates resulted in building up of stresses within the plates, leading to folding, faulting and volcanic activities.

2. what are the three types of plate movement on the earth?

Ans  (1) coverage boundary: When some plates come towards each other, they form a coverage boundary. It may also be cold folding movements

(2) Divergent boundary: when some plates move away from each other they form a divergent boundary. It is also called faulting movements.

(3) Transform boundary: In the event of two plates coming together, they may either collide and crumpled or may slide under each other and formed the transform boundary.

3. Name the major physiographic divisions of India.

Ans The major physiographic divisions of India are:

(1)   Himalayan Mountains

(2)   The Northern Plains

(3)   The peninsular Plateau

(4)   The Indian Desert

(5)   The Coastal Plains

(6)   The Islands

4.Give a brief description of the Himalayan mountains.

Ans  The Himalayas, geologically young and structurally fold mountains stretch over the northern borders of India These mountains ranges run in a west-east directin frm Indus t Brahmaputra .The Himalayas are lofiest and one of the most rugged mountain barriers of the world.They  form an arc ,which covers a distance of 2,400 kilometers.

5.Describe the three parallel ranges of the Himalayas.

Ans.(a)  Himadri (Great or Inner  Himalayas)The northern most range is known as the Great or Inner Himalayas or the ‘Himadri’. It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres. It contains all the prominent Himalayan peaks. It remains snowcovered throughout the year, resulting in to the formation of glaciers and some perennial rivers.

(b)Himachal (Lesser Himalayas)- The range lying to the south of the Himadri forms the most rugged mountain system and is known as Himachal or lesser Himalaya. Theranges are mainly composed of highly compressed and altered rocks. The altitudevaries between 3,700 and 4,500 metres the Pir Panjal range forms the longest and the most important range, the Dhaula Dhar and the Mahabharat ranges are also prominent ones.This range consists of the famous valley of Kashmir, the Kangra and Kullu Valley in Himachal Pradesh. This region is well known

for its hill stations.

(c)Shiwaliks (Outer Himalayas)- The outer most range of the Himalayas is

called the Shiwaliks. They extend over a width

of 10-50 Km and have an altitude varying

between 900 and 1100 metres. These ranges

are composed of unconsolidated rock material , so these ranges are prone to earthquake and landslides

6.Classify the Himalayas on th basis of regions from West to East.

Ans -These divisions have been demarcated by river valleys

(a)Punjab Himalayas: This  part of Himalayas lying between Indus and Satluj has been traditionally

known as Punjab Himalaya but it is also known regionally as Kashmir and Himachal

Himalaya

Kumaon Himalayas-This part of the Himalayas lying between Satluj and Kali rivers.

Nepal Himalayas- This part of the Himalayas lying between Kali and Tista rivers

Assam Himalays- This part lying between Tista and Dihang rivers is known as Assam Himalayas.

7.Why are  the Shiwalik ranges are prone to earthquakes ?

Ans- The Shiwalik ranges are still in the process of folding. This is the youngest range of the Himalayas formed by unconsolidated rock material .Therefore, these ranges are prone to earthquake and landslides.

8.What do you know about ‘Purvanchal’?

Ans- The Eastern Hills are collectively known as Purvanchal.

These hills running through the north-eastern states are mostly composed of strong sandstones which

are sedimentary rocks. Covered with dense forests, they mostly run as parallel ranges and valleys. The Purvanchal comprises the Patkai hills, the Naga hills, Manipur hills and the Mizo hills

9.How are rivrine islands formed?
Ans- The rivers coming from the northern mountains carry alluvium with them and do the depositional work . In the lower course, due to gentle slope, the velocity of river decreases which results in formation of riverine islands.

10.Classify the northern plains on the basis of its location.

The Northern Plain is broadly divided into three sections.

Punjab Plains.- The Western part of the Northern Plain is referred to as the Punjab Plains.Formed by the Indus and its tributaries, the larger part of this plain lies in Pakistan. The Indus and its tributaries–the Jhelum, the Chenab, the Ravi, the Beas and the Satluj originate in the Himalaya.

Ganga plain- The Ganga plain extends between Ghaggar and Teesta rivers. It is spread over the states of North India, Haryana, Delhi, U.P., Bihar, partly Jharkhand and West Bengal

Brahmaputra plain-To the east of Ganga plains lies the Brahmaputra plain .They cover the areas of Assam and Arunachal Pradesh.

11.Classify the northern plains on the basis of the varitions in the relief features.
Ans According to the variations in relief features, the Northern plains can be divided into four regions.
Bhabar- The rivers, after descending from the mountains deposit pebbles in a narrow belt of about 8 to 16 km in width lying parallel to the slopes of the Shiwaliks. It is known as bhabar.

Terai-To the South of  bhabar belt, the streams and rivers re-emerge and create a wet, swampy and marshy region known as terai. This was a thickly forested region full of wildlife. The forests have been cleared to create agricultural land and to settle migrants from Pakistan after partition.

 Bhangar-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.

Khadar-The newer, younger deposits of the flood plains are called khadar. They are renewed almost every year and so are fertile, thus, ideal for intensive agriculture.

12- Give main characteristics of the divison of great peninsular plateau.

The great Peninsular Plateau is the oldest landmass of the Indian subconitent.It is divided into two parts.
1. The Central Highlands
2.The Deccan Plateau
1. The Central Highlands-

(i)These highlands are made up of hard igneous and metamorphic rocks.
(ii)The old Aravali range borders it in the north west.
(iii)The eastward extension of the Malwa Plateau is Known as Bundelkhand and Baghelkhand in southern U.P and northern M.P.
(v)The Malwa Plateau is drained by the southern tributaries of the Yamuna and the Ganga .Damodar river drains the Chotanagpur  plateau.
2.The Deccan Plateau-

(i) The Deccan Plateau extends from river Narmada to southern tip of Peninsular India
(ii) It is one of the oldest earth blocks and made up of hard igneous and metamorphic rocks
(iii)The Satpura ,Mahadev hills, Maikal hills etc form its northern edge.
(iv) The western Ghats form its western edge which is much steeper and higher than the eastern one. The plateau slopes  gently towards the east.
(v) The Eastern edge is marked by Eastern ghats which are broken in to small hills by rivers.

13 What are the  characteristics  of  coastal plains of india?

Ans-

Western coastal plain-

(i) The Peninsular plateau is flanked by stretch of narrow coastal strips, running along the Arabian Sea on the west and the Bay of Bengal on the east.

(ii) The western coast, sandwiched between the Western Ghats and the Arabian Sea, is a narrow plain. It consists of three sections.

(iii)The northern part of the coast is called the Konkan (Mumbai – Goa), the central stretch is called the Kannad Plain while the southern stretch is referred to as the Malabar coast.

Eastern coastal plain-

(i)The plain along the Bay of Bengal are wide and level. In the northern part, it is referred to as the Northern Circar, while the southern part is known as the Coromandal Coast.

(ii)Large rivers such as the Mahanadi, the Godavari, the Krishna and the Kaveri have farmed extensive delta on this coast.

(iii) Lake Chilika is an important feature along the eastern coast

14.Prepare a short note on Indian desert .

Ans-The Indian desest lies towards the western margins of the Aravali Hills. It is an undulating sandy plain covered with sand dunes. This region receives very low rainfall below 150 mm per year. It has arid climate with low vegetatin cover. Streams appear during the rainy season. Soon after they disappear into the sand as they do not have enough water to reach the sea. Luni is the only large river in this region.

Barchans (crescent shaped dunes) cover larger areas but longitudinal dunes become more promiment near the Indo-Pakistan boundary. If you visit Jaisalmer, you may go to see a group of barchans.

15.State the differences between 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. Earlier they were known as Laccadive, Minicoy and Amindive. In 1973 these were named as Lakshadweep. 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 Pitli island, which is uninhabited, has a bird sanctuary.

 Andaman and Nicobar islands- They are bigger in size and are more numerous and scattered. 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 starategic 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.