Physiographically, India can be divided into 3 units:
- Mountains in the North
- Plains in the Northern India & the Coast
- Plateau region of the South
To these can be added the fourth, namely, the coasts and islands
Mountains of India
The Himalayas in India
Means ‘Abode of Snow’. They are one of the youngest fold mountain ranges in the world and comprise mainly sedimentary rocks.
They stretch from the Indus River in the west to the Brahmaputra River in the east. Total length is about 5000 km. The width of the Himalayas varies from 500 km in Kashmir to 200 km in Arunachal Pradesh. Their average height is 2000m.
The Eastern Himalayas – made up of Patkai Hills, Naga Hills, Mizo Hills and the Garo, Khasi and Jaintia Hills – are also known as Purvanchal.
The Pamir, popularly known as the Roof of the World, is the connecting link between the Himalayas and the high ranges of Central Asia.
Can be divided into 3 parallel or longitudinal zones, each with separate features.
The Great Himalayas or The Himadri
- Average elevation extends upto 6000m & some of the world’s highest peaks are here :
Capital Lucknow Area 2,38,566 sq. km Population 166,052,859 Sex Ratio 898 Growth Rate 25.80% Literacy 56.27% Districts 71 Language Hindi and Urdu
- There are few passes and almost all of them have a height above 4,500 m. they include Shipki La and Bara Lapcha La in Himachal Pradesh, Burzil and Zozi La in Kashmir, Niti, Lipulekh and Thag La in Uttarankhand, and Jelep La and Nathu La in Sikkim.
Lesser Himalayas or The Himachal
- Average height of mountains is 3700 – 4500 m.
- Mountains and valleys are disposed in all direction ( mountains rising to 5000 m and the valleys touching 1000 m ).
- Its important ranges are : Dhauladhar, Pir Panjal, Nag Tibba, Mussoorie.
- Important hill resorts are : Shimla, Chhail, Ranikhet, Chakrata, Mussoorie, Nainital, Almora, Darjeeling.
Outer Himalayas or The Shiwaliks
- Lowest range ( average elevation is 900 – 1200 m ).
- Forms the foothills and lies between the Lesser Himalayas and the plains. It is the newest range.
Trans – Himalayan Zone
- This range lies to the north of the Great Himalayas. It has some important ranges like Karakoram, Laddakh, Zanskar, etc. the highest peak in this region is K2 or Godwin Austin ( 8611m, in Pak occupied Kashmir ). Other high peaks are Hidden Peak ( 8068 m ), Broad Peak ( 8047 m ) and Gasherbrum II ( 8035 m ).
- The longest glacier is Siachin in the Nubra valley, which is more than 72 km long ( biggest glacier in the world ). Biafo, Baltaro, Batura, Hispar are the other important glaciers in this region.
- This area is the largest snow-field outside the Polar Regions.
- While the Himalayas are Fold Mountains, they are not.
- The Aravalli Mountains ( Rajasthan ) : World’s oldest. Guru Shikhar is the highest peak on which Mount Abu ( 1,722 m ) is situated.
- The Vindhya Mountains
- The Satpura Mountains ( highest point at Dhupgarh [1,350 m] near Pachmarhi )
- The Western Ghats or Sahyadris : Average height 1200mtrs, 1600km long. Its southern part is separated from the main Sahyadri range by Palghat Gap ( link between Tamil Nadu & Kerala ). Other passes are Thalghat ( connects Nasik to Mumbai ) and Bhorghat (connects Pune to Mumbai).
- The Eastern Ghats ( Highest peak : Mahendra Giri ( 1501 m ) ).
- The Nilgiris or The Blue Mountains : Meeting place of the Western and the Eastern Ghats. Two highest peaks are Dodda Betta and Makurti.
- The highest peak of Peninsular India is Anaimudi ( 2695 m ) in Anaimalai Hills.
- Cardamom hills or Ealaimalai is the southernmost mountain range of India.
Facts about position of states
- UP borders the maximum number of States – 8 ( Uttarakhand, HP, Haryana, Rajasthan, MP, Chhattisgarh, Jharkhand, Bihar ). After UP is Assam, which touches the border of 7 States.
- Tropic of Cancer passes through 8 States : Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, WB, Tripuro, Mizoram.
- Indian Standard Meridian passes through 5 States : UP, MP, Chhattisgarh, Orissa, AP.
- 9 States form the coast of India. They are : Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu. Andhra Pradesh, Orissa and West Bengal.
- 2 Union Territories, viz. Daman & Diu and Pondicherry are also on the coast.
- The Union Territories of Andaman and Nicobar Islands and Lakshadweep are made up of islands only.
The Plains of India
- To the south of the Himalayas and to the north of the Peninsula lies the great plains of North India. They are formed by the depositional works of three major river systems, Indus, Ganga and Brahmaputra. The vast plains of north India are alluvial in nature and the westernmost portion is occupied by the Thar Desert.
- The thickness of the alluvium is maximum in the Ganga plains and minimum in the Western Plains.
- In the Kerala plains are the backwaters or ‘Kayak’, which are the shallow lagoons or inlets of the sea, lying parallel to the coastline. The largest among these is the Vembanad Lake.
- The plains consist of four divisions:
- Bhabar : Along the foothills of Shiwaliks. Highly porous
- Tarai : Re – emergence of streams. Zone of excessive dampness
- Bhangar : Older alluvium of the plains. Studded with calcareous formations called ‘kankar’
- Khadar : New alluvium and forms the flood plains along the river banks.
Peninsular Plateau of India
- Spreads south of the Indo – Gangetic plains flanked by sea on three sides. This plateau is shaped like a triangle with its base in the north. The Eastern Ghats and the Western Ghats constitute its eastern and western boundaries, respectively.
- Narmada, which flows through a rift valley, divides the region into two parts: The Malwa Plateau in the north & the Deccan Plateau in the south.
- Most of the rocks are of the igneous type.
- Vindhya Plateau is situated south of Malwa plateau.
- Chhota Nagpur Plateau lies to the west of Bengal basin, the largest and most typical part of which is the Ranchi plateau.
- The Deccan Plateau is the largest plateau in India. It is made up of lava flows in the Cretaceous – Eocene era through the fissure eruptions.
Islands of India
- Total coastline of India : 7516 km. Longest coastline: Gujarat ( Second longest is of Andhra Pradesh ).
- Indian territorial limits include 248 islands:
The Andaman and Nicobar Group
- Andamans is a group of 204 islands of which the largest is Middle Andaman.
- The Andamans are believed to be extensions of mountains system in the N.E. part of the country.
- Saddle Peak ( 737 m ) in N.Andaman is the highest peak.
- The Nicobars is a group of 19 islands of which the largest is Great Nicobar. Most of them are volcanic in nature.
- Great Nicobar is the southernmost island and is only 147 km away from Sumatra island of Indonesia.
- Volcanic Islands: Barren and Narcondam Islands. Barren is in the process of eruption these days after lying dormant for 200 years.
The Arabian Sea Group
- All the islands in the Arabian Sea ( Total 25 ) are coral islands and are surrounded by Fringing Reefs ( North : Lakshadweep, South: Minicoy ).
- Ten Degree Channel separates Andamans from Nicobars ( Little Andaman from Car Nicobar )
- Duncan Passage lies between South Andaman and Little Andaman.
- Nine Degree Channel separates Kavaratti from Minicoy Island.
- Eight Degree Channel separates Minicoy Island ( India ) from Maldives.