PHYSICAL FEAURES OF INDIA'

1. 1} THEORY OF PLATE TECTONICS

1.1. The movement of the plates results in building up of stress within the plates and the continental rocks above leading to Folding, Faulting and Volcanic activity.

1.2. These plate movements are classified into three types:

1.2.1. CONVERGING PLATES The tectonic plates move closer to each-other in convergent plate boundaries. The two platescoming together may either collide or may slide under the other Convergence of plates, may result in activities like an earthquake. Formation of Himalayas is a result of convergence of plates

1.2.2. DIVERGING PLATES Tectonic plates move away from each other in divergent plate boundaries. The two plates drift away from each other creating gap between the two. The divergence of plates may result into a volcanic eruption. Formation of Great Atlantic drift is a result of the divergence of plates.

1.2.3. TRANSFORM BOUNDARY In the event of two plates coming together they 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. Such movements have influenced the evolution of present landforms of India

1.3. According to this theory, the crust of the Earth has been formed out of seven major and some minor plates.

2. 4} MAJOR PHYSIOGRAPHIC DIVISIONS

2.1. THE HIMALYAN MOUNTAINS

2.1.1. LONGITUDINAL EXTENT

2.1.1.1. HIMADRI

2.1.1.1.1. H=6000 m

2.1.1.1.2. continuous range

2.1.1.1.3. prominent and loftiest peaks

2.1.1.1.4. asymmetrical

2.1.1.1.5. composed of granite

2.1.1.1.6. snow bound and many glaciers decend from it

2.1.1.2. HIMACHAL

2.1.1.2.1. COMPOSED OF HIGHLY COMRESSED AND ALTERED ROCKS

2.1.1.2.2. h=3700-4500m

2.1.1.2.3. width=50Km

2.1.1.2.4. PIR PANJAL (THE LONGEST RANGE) .DHAULA DHAR AND MAHABHARTA RANGE ARE ALSO PROMINENT ONES

2.1.1.2.5. VALLEY-FAMOUS VALLEY OF KASHMIR,THE KANGRA AND KULLU VALLEY IN HIMACHAL PRADESH

2.1.1.2.6. WELL KNOWN FOR IT'S HILL STATION

2.1.1.3. SHIWALIKS

2.1.1.3.1. WIDTH-10-50Km

2.1.1.3.2. h=900-1100m

2.1.1.3.3. composed of unconsolidated sediments brought down by riversfrom the main himalyan ranges

2.1.1.3.4. its valleys are covered with gravel and alluvium

2.1.1.3.5. the longitudinal valley lying between himachal and shiwaliks are known as duns .EG:DEHRA DUN , KOTLI DUN AND PATLI DUN.

2.1.2. LATITUDINAL EXTENT

2.1.2.1. Punjab Himalayas:- This part lies between the Indus and Sutlej.

2.1.2.2. Kumaon Himalayas: This part lies between Sutlej and Kali rivers.

2.1.2.3. Nepal Himalayas: This part lies between the Kali and Tista rivers.

2.1.2.4. Assam Himalayas: This part lies between the Tista and Dihang rivers .

2.1.3. PURVANCHAL

2.1.3.1. Beyond the Dihang gorge, Himalayas bends sharply to the south

2.1.3.2. spread along the eastern boundary

2.1.3.3. They are mostly composed of strong sandstones which are sedimentary rocks.

2.1.3.4. They form a natural frontier between India and Myanmar.

2.1.3.5. They are covered with dense forest and mostly run as parallel range.

2.1.3.6. It is comprised of Patkai Hills, Naga Hills, Manipur hills, and Mizo hills.

2.2. THE NORTHERN PLAINS

2.2.1. The Northern Plains of India are one of the most important features of physiography of India.

2.2.2. Himalayan and peninsular rivers have made up this vast Plain by depositing alluvial soil.

2.2.3. It has been formed by the three major rivers systems-the Indus, the Ganga and the brahmaputra

2.2.4. It is the most densely populated physiography division. Agriculturally, It is the most

2.2.5. It is the most productive area because of rich soil combined with adequate water supply and favourable climate.

2.2.6. The Northern Plain is broadly divided into three sections:

2.2.6.1. (a) The Punjab Plain - It is the western part of the Northern Plain formed by the Indus and its tributaries. This section is dominated by the Doabs.

2.2.6.2. (b) The Ganga Plain - It is the largest part of the Northern Plain and extends between Ghaggar and Teesta rivers.

2.2.6.3. (c) The Brahmaputra Plain - It forms the eastern part of the Northern Plain by the river Brahmaputra and its tributaries. It is narrower than the Ganga Plain, and it is a floodprone area. In the south-east side of the Northern Plain lays the Ganga-Brahmaputra delta which is the largest delta of the world.

2.2.7. The difference in relief has led the North Indian Plains to be divided into four zones :

2.2.7.1. • Bhabar— lying at the foot of Shivalik, a narrow 8 to 16 km wide belt of pebbles.

2.2.7.2. • Terai— lying next to Bhabar, a wet and marshy area with wildlife and forests.

2.2.7.3. • Bhangar— Older alluvium plain which rises above the level of the flood plains.

2.2.7.4. • Khadar— Younger alluvium of the flood plains.

2.3. THE PENINSULAR PLATEAU

2.3.1. • Peninsular plateau is a tableland,composed of the old crystalline Igneous and metamorphic rocks.

2.3.2. • It is formed due to the breaking and drifting of the Gondwanaland.

2.3.3. • The plateau has broad and shallow valleys and rounded hills.

2.3.4. • The plateau consists of two broad divisions, namely the Central Highlands and Deccan Plateau.

2.3.5. WESTERN GHATS

2.3.5.1. Mark the western boundary of the peninsular plateau, stretching from Gujarat to Kerala.

2.3.5.2. It is a regular stretch of highland

2.3.5.3. The Western Ghats are comparatively more in height, i.e. from 900-1600m.

2.3.5.4. The Western Ghats receive more rainfall due to orographic rainfall.

2.3.5.5. The highest peak of Western Ghats is AnaiMudi, followed by Doda Betta.

2.3.6. EASTERN GHATS

2.3.6.1. Mark the eastern boundary of the peninsular plateau, stretching from Orissa to Kerala.

2.3.6.2. They are dissected and irregular because of the major rivers flowing through them.

2.3.6.3. Height of Eastern Ghats is comparatively less than western Ghats ranging from 600-900m.

2.3.6.4. Rainfall received is comparatively less because The monsoon winds move parallel to the Eastern Ghats

2.3.6.5. Highest peak of Eastern Ghats is Mahendragiri.

2.4. THE COASTAL PLAINS

2.4.1. WESTERN COASTAL PLAINS

2.4.1.1. Western Coastal Plains is a belt of the plainregion lying towards west between the Western Ghats and the Arabian Sea.

2.4.1.2. This belt of plains is narrow.

2.4.1.3. Western coastal plains are less fertile because no major river is engaged in sediment Deposition.

2.4.1.4. Western plains receive more rainfall.

2.4.1.5. From North to South, Western Coastal plains are divided into Konkan Coast, Kannada Coast and Malabar Coast

2.4.2. EASTERN COASTAL PLAINS

2.4.2.1. Eastern Coastal Plains is a belt of plain region lying towards the east between Eastern Ghats and Bay of Bengal

2.4.2.2. Eastern Coastal Plains are comparatively wider.

2.4.2.3. Eastern coastal plains are very fertile because rivers like Mahanadi, Godavari, Krishna, Kaveri deposit their sediments during delta formation

2.4.2.4. Eastern plains receive comparatively lesser rainfall.

2.4.2.5. From North to South, Eastern Coastal plains are divided into Northern Circars and Coromandel Coast.

2.5. THE ISLANDS

2.5.1. India has vast mainland. Beside this the country also has two groups of islands:

2.5.1.1. ANDAMAN AND NICOBAR ISLANDS

2.5.1.1.1. These island groups are located in Bay of Bengal extending from north to south.

2.5.1.1.2. It is believed that these islands are elevated portions of sub marine mountains.

2.5.1.1.3. Andaman and Nicobar is an elongated chain of islands

2.5.1.1.4. These island groups are far away from the mainland.

2.5.1.1.5. Administrative unit is Port Blair.

2.5.1.1.6. There is a great diversity of flora & fauna here too. It has thick forest cover.

2.5.1.2. LAKSHADWEEP ISLANDS

2.5.1.2.1. These islands are located in the Arabian Sea. lying close to the Malabar coast of Kerala.

2.5.1.2.2. They are formed because of coral deposition.

2.5.1.2.3. Lakshadweep is a cluster of islands.

2.5.1.2.4. This island group is closer to the mainland

2.5.1.2.5. Administrative unit is Kavaratti.

2.5.1.2.6. This island group has great diversity of flora and fauna Pitti island here is uninhabited & has a bird sanctuary.

2.6. THE INDIAN DESERTS

2.6.1. It lies towards the western margins of Aravalli’s

2.6.2. Indian desert is an undulating sandy plain covered with dunes.

2.6.3. The region receives very low rainfall below 150mm per year.

2.6.4. The region has an arid climate with low vegetation cover.

2.6.5. Barchans (crescent-shaped dunes) and dunes cover a large area of the desert.

2.6.6. Luni is the only major seasonal river in this region.

3. 2} FORMATION OF HIMALYAS

3.1. Its northern part was the Angara land, and the southern part was the Gondwana land.

3.2. The oldest landmass the (Peninsular plateau) was a part of this Gondwana land. The Gondwana land included India, Australia, South-Africa, South America & Antarctica as one single landmass

3.3. The convectional currents split the crust into some pieces, thus leading to the drifting of the IndoAustralian plate after being separated from the Gondwana land, towards the north.

3.4. The northward drift resulted in the collision of the plate with the much larger Eurasian Plate.

4. 3} FORMATION OF NORTHERN PLAINS

4.1. After the formation of the Himalayas out of the Tethys Sea, the large basin was formed at the foothills of the Himalayas.

4.2. There after, the deposition of alluvium in the large basin was done for the millions of years. This deposition was done mainly by the three river systems – Indus, Ganga, and the Brahmaputra.

4.3. Aflat land of extensive alluvium deposits led to the formation of the Northern Plains of India

5. 5} HOW DOES THE LAND OF INDIA DISPLAYS GREAT PHYSICAL VARIATIONS?

5.1. The Peninsular Plateau constitutes one of The Ancient- Landmasses On The Earth’s Surface.

5.2. The Himalayas & the Northern Plains are the most recent landforms.

5.3. The whole mountain system of Himalayas represents a very youthful topography.

5.4. The Northern Plains are formed of alluvium deposits.

5.5. The peninsular plateau is composed of igneous & metamorphic rocks with gently rising hills & wide valleys

6. 6} THE DIVERSE PHYSICAL FEATURES OF INDIA MAKES THE COUNTRY RICHER IN ITS NATURALRESOURCES

6.1. -The northern mountains are the major source of water and forest wealth.

6.2. -The northern plains provide us with a number of crops.

6.3. -The plateau is the storehouse of the minerals which is highly important for the industrialisation of the country.

6.4. -The coastal region and island groups provide sites for fishing and port activities.

6.5. Thus, we can say that the diverse Physical features of India make the country richer in its natural resources that can be helpful for future development.