Physiographic Division of India

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India's physical structure is a result of long and complex geological history involving various tectonic activities such as folding, faulting, volcanic eruptions, metamorphism, and sedimentation. It includes diverse landforms such as the Himalayas, plains, plateaus, deserts, coastal plains, and islands. Approximately 10.77% area is occupied by Mountains, 18.5% by Hills, 27.7% by Plateaus and 43.2% by the Plains.
The Indian landmass can be broadly divided into the 6 physiographic divisions:

 

1.     The Northern and North-eastern Mountains
2.     The Northern Plains
3.     The Peninsular Plateau
4.     The Indian Desert
5.     The Coastal Plains
6.     The Islands

The Northern and North-eastern Mountains

 

Origin and Formation of Himalayas

• Plate tectonic theory based on the concept of Sea-floor Spreading (given by Harry Hess) best describes the Origin of the Himalayas.
• Formed during the Tertiary period due to the collision of the Indian plate and the Eurasian plate.
• Indian Plate getting Sub-conducted under the Eurasian Plate.
• The upliftment of the Himalayas took place in different phases, with the Shiwalik being the newest.

 

Vertical or Latitudinal division of the Himalayas

1. Trans Himalayas
2. Greater Himalayas
3. Lesser Himalayas
4. Shiwalik Himalayas

 

1. Trans Himalayas/ Tibetan Himalayas:

• These ranges have been found from Sedimentary rocks.
• The rocks from Tertiary period to Cambrian period are found here
• Antecedent rivers like Indus, Sutlej, Brahmaputra originate from this range.
• Highest mountain peak of this range is K2 (Godwin Austen) at POK in Karakoram range.
• Trans Himalayas and Greater Himalayas are divided by ITSZ (Indo-Tsangpo-Suture-Zone)
• Karakoram, Ladakh, Zaskar, Kailash are the important ranges of this region.

 

Karakoram Range

• Highest peak of Karakoram range is K2 (Godwin Austen).
  • Siachen (76 km), Biafo (63 km), Baltoro (62 km), Hispar (61 km) are the four major Glacier in the Karakoram range.
  • Siachen is known as ‘White water in India’, located at Nubra valley.
  • K2 is also known as ‘Savage’ mountain because of its dark history and incredibly high death.
  • Rakaposhi is one of the World’s steepest mountain peak located in Karakoram range at Gilgit-Baltistan in POK.

Ladakh Range

• Highest peak of Ladakh range is Stok Kangri.

 

Zaskar Range

• Highest peak of Zaskar range is Kamet.

 

Kailash Range

• Highest peak of Kailash range is Kailash.

 

2. Greater Himalayas/ Centre Himalayas:

• Greater Himalayas known as the Inner Himalaya or Himadri.
• Great Himalayan ranges is also known as the Central Axial ranges.
• Average highest of this region is 6100 m. and width of 25 km.
• Contains major peaks of the World like, Nanga Parbat (8124 m), Nanda Devi (7816 m), Mt. Everest (8848.86 m), Kanchanjunga (8598 m), Kamet (7756 m), Namcha Barea (7765 m).
• Important Pass: The Burzil pass and Zojila pass in J&K, Bara Lacha pass and Shipkila pass in Himachal Pradesh, The Thagala pass, Niti pass and Lipu Lakh pass in Uttarakhand and the Nathula pass, Jelep La in Sikkim.
• The Great Himalayas is separated from the Lesser/Middle Himalayas by the Main Central Thrust (MCT).

 

3. Lesser Himalayas/ Middle Himalayas:

• This region known as Himachal.
• The average highest is 3000-4500 m and width/breadth 60-80 km.
• Kashmir valley and Lahul, Spiti, Kangra and Kullu Valley of Himachal Pradesh are located here. This ranges are also famous for Hill Stations like, Shimla, Almora, Nainital, Ranikhet and Darjeeling.
• Middle Himalayas and Shiwalik Himalayas are divided by the Main Boundary Thrust (MBT).
• Ranges: Pir Panjal, Dhauladhar, Nag Tibba, Mahabharat.

 

Pir Panjal Range

• Pir Panjal ranges located in Kashmir, and it is the longest and most important range of the Himalaya.
• Two famous passes present in Pir Panjal range are Burzila pass and Banihal pass.
• Karewas are alluvial deposits of different Soil and sediments such as sand, Clay, Silt, Shale, Mud, Lignite and Loess found on the slop of Pir-Panjal in J&K.
• Karewas are well known for the cultivation of Saffron called Zafron.
• Karewas are also found in the valley of Bhadarwa valley.

 

4. Shiwalik Himalayas/ Outer Himalayas:

• Shiwalik Himalayas are formed in ‘Cenozoic Era’.
• The southern and the outermost ranges of the Himalayas are known as the Shiwalik.
• Shiwalik Himalayas are the youngest mountain ranges of the Himalayas.
• Average highest 600-1200 m and breadth is about 10-50 Km.
• This ranges are composed of the unconsolidated sediments brought down by rivers from the main Himalayan ranges located fer in the north. These valleys are covered with thick gravel and Alluvium.
• Longitudinal Valleys, conical forests, and small grasslands are found between the southern slopes of the Middle Himalayas and the Shiwalik ranges, which are known as Duns in west, Duars in East, Bugyals in Uttrakhand and also known as Medos.
• The lower region of Shiwalik Himalayas is known as Terai.
• Shiwalik Himalayas are separated from the Ganga plains by Himalayan Front Fault (HFF).
• Famous Duns: Dehradun, Kotlidun, Patlidun.
• Famous Duars: Haridwar.

 

Key Facts:

• Pamir Knot: Junction of notable mountains like Tain Sham, Karakoram, Kunlun, Hindu Kush, and Himalayan Mountain range.
• Hindu Kush: Covers Afghanistan, Pakistan, Tajikistan.
• The Siwalik Himalayas are called in Arunachal Pradesh are Dhang.
• Old name of Mt. Everest- Peak (XV).
• Highest peak of India – K2 (8611 m). Located in Karakoram range (Trans Himalayas)
• Highest peak of India in Himalaya- Kanchanjunga (8598 m).
• Undisputed highest peak of India is- Nanda Devi (7817 m).
• Highest of all fold mountains of the world- Himalaya.
• Oldest fold mountain in India is Aravalli.
• Longest of all Fold mountains in the World is Andes (Chile, South America).

 

Horizontal or Longitudinal division of the Himalayas

Sir S. Burrad divided the Himalayas longitudinally into 4-sub divisions based on river valleys.

1. Kashmir Himalayas
2. Kumaon Himalayas
3. Nepal Himalayas
4. Assam Himalayas

 

1. Kashmir/ Punjab Himalayas:

• Laying between from the Indus River in the west to the Sutlej River in the east.
• This region includes the Union Territories of Jammu & Kashmir, Ladakh and Himachal Pradesh which covers Karakoram, Ladakh, Zaskar, Pir-Panjal and Dhulandhar ranges.
• Stretches for 560 Km, It the widest part of Himalayas with an extension of 250-400 Km.
• The famous glacier of south Asia like, Siachen and Baltoro are located in this range. Fresh water lake like Dal and Wular and Salt water lake like, Pangong Tso and Tso Moriri are found here.

 

2. Kumaon Himalayas:

• It has wide area of 320 Km between the Sutlej in the west and Kali River in the east in Uttrakhand.
• Highest peak of this region is Nanda Devi (7817 m).
• Western part known as Garhwal Himalayas and Eastern part known as Kumaon Himalayas. The altitude of Kumaon Himalayas is more as compared to the Kashmir/Punjab Himalayas.
• Badrinath, kedarnath, Trishul, Mana, Gangotri, Nanda Devi, Kamet etc. are the major peak of this range.
• The origins of Ganga and Yamuna rivers, Gangotri and Yamnotri glaciers are located here.
• Lakes: Nainital, Bhimtal, Sattal in Uttrakhand are located in this range.
• Passes like Mana and Niti are also located here.

 

3. Nepal Himalayas:

• It extends upto 800 km between Kali River (Sharda) in the west and Teesta River in the east.
• Nepal Himalayas is higher in altitude as compared to the Kumaon Himalayas.
• This range known as This range known as Sikkim Himalayas in Sikkim, Darjeeling Himalayas in West Bengal and Bhutan Himalayas in Bhutan.
• Highest peaks are Mt. Everest, Annapurna, Dhaulagiri, Makalu, Kanchanjunga etc.
• It is the most prominent and massive portion of the Himalayas, containing some of the highest peaks in the world; Mount Everest, Annapurna, Dhaulagiri, Makalu, Kanchanjunga etc.

 

4. Assam Himalayas:

• It extends upto 800 km between Kali River in the west and Teesta River in the east, which is less altitude as compared to the Kumaon Himalayas and Nepal Himalayas.
• It is spread in the Indian states of Assam, Arunachal Pradesh, Sikkim and Bhutan.
• Namcha Barwa is the Highest peak of this range.
• Jelep la, Bondi La, Sela, Yangyap and Karpo La are the important passes located in this section.

 

Key Facts:

• Shimla is located in Dhauladhar range.
• Kashmir Himalayas are famous for Karewas.
• The valley of Kashmir is located on a tectonic Nappe structure.
• ‘Tal’ means Lake like Nainital, Bhimtal etc.
• ‘La’ means Pass like Jelep La, Bondi La etc.
• ‘Milam’ glacier located at Pithoragarh district (Uttarakhand) in Kumaon Himalayas.
• Mount Everest also known as Sagar Matha in Nepal, which means ‘Forehead of the Sky.’
• In Tibet, Mount Everest is called Chomolungma, which means ‘Goddess Mother of the World.’
• In India (especially in traditional or religious contexts), it is sometimes referred to alongside Mount Gaurishankar, a nearby sacred peak in Nepal, but Gaurishankar is a separate mountain, not an alternate name for Everest.

 

The Eastern Himalaya or Purvanchal Hills

• The Eastern Himalayas, also referred to as the Purvanchal Hills, constitute the easternmost extension of the Himalayan Mountain system in India. This region spans across the eastern part of Arunachal Pradesh, and continues through Nagaland, Manipur, Mizoram, Tripura, and parts of Meghalaya and Assam.
• After crossing the Dihang or Brahamaputra gorge, the Himalayas take a sudden south ward turn and form a series of comparatively low hills running in the shape of a Erescent (half Moon).
• In the North, they are known as Patkai Bum, which are forms the international boundary between A.P and Myanmar.

 

Key Facts:

• Garo, Khashi, Jaintia hills were formed in the same age as Malwa Plateau.
• West to East: Garo- Khasi-Jaintia- Mikir- Naga.
• North to South: Patkai Bum- Naga- Mani- Mizo.
• Mizoram is also known as Molassis Basin.
• ‘Arakan Yoma’ is the extension of Himalayas, located in Myanmar.
• The mountain range lies between Indian and Myanmar is **Lushai hill **(Lushai hills also known as Mizo hills).
• The Blue Mountain locally known as Phawngpui is the highest peak of Mizoram, located in the Lushai Hills near the Myanmar border.

 

Important Peaks of the Himalayan Mountains

 

Table 1: Important peaks of Himalayan mountains

 

 

Major Valleys of India

A valley is a low-lying area between hills or mountains. In Geography the fertile plains of the rivers are known as the river valley.

 

• Kashmir Valley: Located in Jammu & Kashmir between the Pir Panjal and Zaskar ranges.
• Kangra Valley: Located in Himachal Pradesh between Dhauladhar and Shivalik ranges. Important cultural tourist site like Dharamshala is located in this valley.
• Kullu Valley: It is situated between Dhauladhar and Pir Panjal in Himachal Pradesh. This valley is called as the Valley of Gods.
• Spiti Valley: Located in Trans-Himalayan region in Himachal Pradesh. Tabo Monastery is situated here and it is famous for Buddhist monasteries.
• Markha Valley: It is the famous valley of Ladakh in Zanskar range.
• Sangla Valley: It is located at Kinnaur district of Himachal Pradesh, this valley also known as Baspa valley.
• Chumbi Valley: It is located in Sikkim-Bhutan-China tri-junction. Important tourist sites like Chumbi, Bharour, Dalhousie and Khajjiar are located in this valley.
• Yumthang Valley: Located in North Sikkim. This valley is also known as Valley of Flowers of Sikkim.
• Silent Valley: It is located in the Palakkad district of Kerala in Nilgiri hills of Western Ghats.

 

Peninsular Plateau

The Peninsular Plateau of India is one of the most ancient and stable landmasses in the Indian subcontinent. Geologically, it is a part of the Gondwana landmass, which drifted and collided with the Eurasian Plate to eventually form the Indian Plate. This plateau lies to the south of the Indo-Gangetic Plain and is bordered by the Western Ghats on the west and the Eastern Ghats on the east. It occupies a vast area covering most of central and southern India, including parts of Madhya Pradesh, Maharashtra, Chhattisgarh, Jharkhand, Odisha, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu, and Kerala.

 

• One of the most ancient or oldest and largest landmasses in India.
• This physical division formed during the Cretaceous period/ Eozoic Era.
• Composed mostly of Igneous rock (Granite and Basalt) and Metamorphic rocks (Gneiss).
• Average height of this division is 600-900 metre.
• Direction of average slope of this division towards North-West to South-East.
• The shape of Peninsular plateau in India is Triangular.

 

Peninsular Plateau divided into 3 parts:

1. Central Highlands.
2. Deccan Plateau.
3. Meghalaya Plateau.

 

1. Central Highlands

 

Marwar Upland:

• Lies east of the Aravallis cover eastern part of Rajasthan.
• Composed of sandy, weathered rocks gradually merging with the Thar Desert.

 

Malwa Plateau:

• Volcanic origin, composed of basaltic rocks (Deccan Trap).
• Covers South-East Rajasthan and Western part of Madhya Pradesh.
• Bounded by the Vindhyas and Aravallis.
• Rivers: Chambal, Kali Sindh, Mahi, Betwa etc.
• Soil: Fertile black soil (suitable for cotton and soybean).

 

Bundelkhand:

• Lies between the Yamuna and Betwa Rivers.
• Covers South-West Uttar Pradesh and North-West Madhya Pradesh.
• Made of granite and gneissic rocks.
• Rocky, infertile, drought-prone terrain.
• Soil: Red soil.

 

Baghelkhand:

• Lies between the Son and Mahanadi rivers.
• Covers South Uttar Pradesh and North-West Madhya Pradesh.
• Made of granite and gneissic rocks.
• Rugged terrain with uneven rock outcrops and low population density.

 

Rewa Plateau:

• Located between Kaimur hills (north) and Maikal Range (south).
• Transitional area between Bundelkhand and Chotonagpur and covers South-East Madhya Pradesh.

 

Dandakarnya Plateau:

• Covers parts of Chhattisgarh, Odisha, Telengana and Andhra Pradesh.
• Densely forested and inhabited by tribal communities.
• Formed of old crystalline rocks.

 

Chotonagpur Plateau:

• Composed of Archaeon rocks of Granite and Gneiss, covers Jharkhand and Western part of West Bengal.
• Richest mineral belt of India: coal, iron ore, mica, bauxite, uranium. Called as Store house of Minerals.
• Highest peak of this region is Pareshnath, located in Jharkhand.
• Chotonagpur Plateau is a Dissected plateau.
• Chotonagpur plateau is a Front Sloping.
• Pene plains are formed in Chotonagpur Plateau and Pat land or Monadnocks are shown in Chotonagpur plateau. Pat lands are Flat topped hills.
• This region is divided into three parts: Hazaribag hills, Ranchi hills, and Rajmahal hills.

 

2. Deccan Plateau

• Lies south of the Narmada River, forming the largest and most prominent part of the Peninsular Plateau.
• Bounded by Western ghats on the west, Eastern ghats on the east and Satpura and Vindhya ranges to the north.
• Covers major parts of Maharashtra, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu, and portions of Chhattisgarh, Odisha, Kerala, and Madhya Pradesh.
• It is the largest and oldest division of Peninsular plateau composed of Basalt rocks.
• This region associated with Deccan trap, means Stair steps. Deccan Trap formation was caused by flood basalt eruption.
• Highest peak of Deccan plateau is Anaimudi (2695 m), also the highest peak of South India, located at Kerala.

 

Maharashtra Plateau:

• Northern Deccan, formed by Deccan Traps (basaltic lava).
• Black soil (regur) suitable for cotton cultivation.
• Rivers: Godavari, Bhima, Krishna.
• Western Ghats is known as Sahyadri in Maharastra, Goa and Karnataka. It can be divided into two parts- North Sahyadri and South Sahyadri. 160N latitude divide North and South Sahyadri, which passes through Goa.

 

Karnataka Plateau:

• Also called Mysore Plateau.
• Lies between the Western Ghats and Eastern Ghats.
• Highest peak of Karnataka plateau is Mulangiri (1923 m).
• Divided into Malnad (hilly region), Maidan (erosional plains of Malnad), and coastal tracts.
• Rivers: Tungabhadra, Kaveri, Penner.

 

Telangana Plateau:

• Composed of Archaean granites and gneisses.
• Lies between Godavari and Krishna basins.
• Fertile but rocky and dissected terrain.
• Includes parts of eastern Maharashtra and western Andhra Pradesh.
• Highest peak of Telengana plateau is Armakonda (1688 m).

 

Chhattisgarh Plain (or Basin):

• Located in the northeast Deccan, enclosed by Maikal Hills, Satpura Range, and Odisha hills.
• This region is drained by Mahanadi River and its tributaries.

 

Tamil Nadu Uplands:

• Southern extension of the Deccan.
• The Western ghats meets Eastern ghats in the south at Nilgiri Hills.
• The highest peak of south India is Anaimudi (2695 m), which located on the Annamalai hills. Dodabetta (2637 m) is the second highest peak of south India.
• Dodabetta in Nilgiri hills also the highest peak of Nilgiri Hills.

 

3. Meghalaya Plateau

• The Meghalaya Plateau is a part of the Peninsular Plateau, situated in the north-eastern region of India.
• Meghalaya plateau is also known as 'Shillong Plateau'- named by S.P. Chatterjee.
• It was once a part of the Deccan Plateau, but got separated due to the formation of the Rajmahal-Garo Gap.
• Meghalaya Plateau is composed mainly of Gondwana rocks.
• The Meghalaya plateau or Shillong plateau is farther divided into 3 sub-sections hill region:

  • Garo Hills:

    • Located in the western most part of the Meghalaya Plateau.
    • Garo hills named after the indigenous Garo tribe, who predominantly inhabit in this region.
    • Highest peak of Garo hills is Nokrek peak (1,515 m).

  • Khasi Hills (Central Meghalaya):

    • Located in the central part of the Meghalaya plateau.
    • Known for heavy rainfall; Cherrapunji and Mawsynram.
    • Significant for limestone caves and karst topography
    • Highest peak of Khasi hills is Shilong (1,961 m).

  • Jaintia Hills (Eastern Meghalaya):

    • Located in the eastern part of Meghalaya plateau.
    • Named after the indigenous Jaintia tribe, a sub-group of the Khasi.
    • Known for limestone caves, coal mining, biodiversity, and living root bridges.
    • Famous for karst topography (formed by limestone erosion).

 

Key Facts:

• Highest peak of Naga hills is Saramati (3,840 m).
• Highest peak of Tripura is Belting Shib (1,000 m).
• Highest peak of Meghalaya or Meghalaya plateau is Shillong.

 

Western Ghats

• Run parallel to the western coast of India from north to south.
• Stretch through the states of Gujarat (southern tip), Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu.
• A block mountain formed by faulting during the break-up of Gondwana.
• Steep escarpment towards the Arabian Sea, gentle slope on the eastern side.
• Act as a watershed between rivers flowing east and west.
• Highest peak of Western Ghats is Anaimudi in Anaimalai hills at Kerala.
• Southern most range is Cardamom hill at the border of Kerala and Tamil Nadu.
• Western Ghats is also known as the Sahyadri Hills in Maharashtra and Goa.
• One of the eight ‘hottest hotspots’ of biodiversity in the world.
• Serve as the climatic divide between the coastal plains and the Deccan Plateau.
• The average heights of Western Ghats are 1,000 m to 1,300 m as compared to Eastern Ghats which are 600 m high.
• Western Ghats extend for a length of 1600 km from the Tapi river valley in the north to Nilgiri Hills in the South.
• The four important passes from north to south are Thalghat, Bhorghat, Palghat, and Shenocottah Gap.
  • Thal Ghat: Links Nasik to Mumbai.
  • Bhor Ghat: Links Mumbai to Pune.
  • Pal Ghat: Between Nilgiri to Anaimalai Hills.
  • Shenocottah Gap: Links Tenkasi to Kollam.
  • Charmadi Ghat: Links Mangalore to Chikmagalur.

 

Table 2: Major Peaks of Western Ghats:

 

 

Eastern Ghats

• The Eastern Ghats are a discontinuous mountain range running along the eastern coast of India.
• Unlike the Western Ghats, they are older, lower in elevation, and highly eroded.
• Average height of the Eastern Ghats is 900 - 1,000 m.
• Notified as a biodiversity-rich region, though less studied compared to the Western Ghats.
• Stretch from the Mahanadi Valley (Odisha) to the Nilgiri Hills (Tamil Nadu).
• Run parallel to the Bay of Bengal, but broken by many rivers in the middle. Discontinuous due to river erosion and tectonic activity.
• States covered: Odisha, Andhra Pradesh, Telangana (eastern parts), Parts of Karnataka, and Tamil Nadu.
• Composed of archaic crystalline and metamorphic rocks.
• Geologically older than the Western Ghats.

 

Table 3: Major Peaks of Eastern Ghats

 

 

Key Facts:

• Highest peak of Western Ghats is Anaimudi in Anaimalai hills at Kerala.
• Highest peak of Eastern Ghats is Jindhagada peak in Araku valley of Andhra Pradesh.
• Southern most range is Cardamom hill at the border of Kerala and Tamil Nadu.

 

Great Northern Plains

• The Great Northern Plains of India are an extensive alluvial plain formed by the depositional work of the three major river systems: the Indus, Ganga, and Brahmaputra.
• The great plains are located South to the Shiwalik, separated by the Himalayan Front Fault (HFF).
• Extend from the Indus River in the west (Punjab) to the Brahmaputra River in the east (Assam).
• Stretch across the states of Punjab, Haryana, Delhi, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Assam, and parts of Rajasthan.
• Slopes gently from northwest to southeast.
• This plain is formed during the Quaternary period, and is composed of deep layers of alluvium, ranging from 1,000 to 2,000 metres thick in some places.
• Geologically, they are one of the youngest landforms in India.
• Northern plain is divided into 4 parts on the basis of difference in physical characteristics. These are Bhabar, Terai, Bhangar and Khadar.

 

Bhabar:

• The flat plains along with the sub-Himalayan region in North India are called as Bhabar.
• Narrow belt (8–16 km) at the Himalayan foothills.
• Composed of coarse pebbles and sediments.
• Highly porous: rivers disappear here and reappear in the Terai.

 

Terai:

• Marshy, swampy zone south of Bhabar.
• Springs and re-emerging streams make it water-logged.
• Densely forested, highly fertile; cleared for agriculture.
• In West Bengal, the western part of Teesta river known as Terai.

 

Bhangar:

• Older alluvium, slightly elevated from river courses.
• Contains calcareous concretions known as Kankar.
• Less fertile than Khadar.

 

Khadar:

• Newer alluvium deposited by annual floods.
• Found in the active floodplains of rivers. It is found in flood plains of eastern Uttar Pradesh, Bihar and West Bengal.
• Extremely fertile, ideal for agriculture.

 

Regional Divisions of the Northern Plains

Northern plains mainly classified into 4 parts, there are-

 

The Punjab Plains

• This plain is formed by five important rivers of Indus system: Jhelum, Chenab, Ravi, Beas, Sutlej.
• Panjab means the land of five rivers, Jhelum, Chenab, Ravi, Beas and Sutlej.
• The new alluvial soil of Punjab is Bet.
• The old alluvial soil of Punjab is Dhaya.
• Doabs (land between two rivers) are a distinct feature of this region.
  • Bari Doab: Bari Doab lies between the rivers Beas (to the east) and Ravi (to the west). In India, parts of Amritsar, Gurdaspur, and Pathankot districts fall within the Bari Doab zone.
    • Bist Doab: Lies between Beas and Sutlaj river, located in the eastern part of Indian Punjab.
    • Rechna Doab: Rachna Doab lies between the Ravi River (to the east) and the Chenab River (to the west). Located to the west of the Bari Doab.
    • Chaj Doab: Chaj Doab lies between the Chenab River (to the east) and the Jhelum River (to the west).
    • Sind-Sagar Doab: The Sindh Sagar Doab lies between the Indus River (to the west) and the Jhelum River (to the east).

 

Ganga Plains

• Ganga plains is the largest unit of the Great Indian plain, extends from Yamuna River (Delhi) to Rajmahal Hills (Jharkhand–West Bengal border).
• The general slops of the entire plain are to the east and south-east.
• The only one Doab of Ganga plain is ‘Ganga-Yamuna doab’, which is the largest doab in India.
• The New alluvial soil of Ganga plains is called Khadar and Old Alluvial soil is called Bhangar.

 

Rajasthan Plains

• Occupied by the Thar or the Great Indian Desert.
• Lies west of the Aravalli Range, between the Luni River and the Indo-Pak border.
• Eastern side has many hills. Sand Dune is the prominent landforms here, locally known as Dhrian.
• New alluvial soil of Rajasthan is known as Rohi and Old alluvial soil is known as Thali.

 

Assam Plains or Brahmaputra Plains

• Found in Assam and some parts of Arunachal Pradesh.
• Formed by Brahmaputra River and its tributaries (Subansiri, Manas, Dibang etc.).
• New alluvial soil of Assam plains is known as Duars.
• The Cachar plains of Assam is formed by the Surma River (Barak River).

 

Key Facts:

• Largest Doab in India is ‘Ganga-Yamuna doab’.
• Doab means, Land between two rivers (Do = Two, Ab = Water).
• Western most boundary of Northern plains is Punjab.
• Eastern most boundary of Northern plains is Assam.
• Total area of the Great Northern plains is 7.8 lakh sq. km.

 

Indian Desert

• Lies in the north-western part of India, primarily in western Rajasthan, on the western side of the Aravallis.
• Extends into eastern Pakistan, especially into Sindh and Punjab provinces.
• Covers parts of Rajasthan (Barmer, Jaisalmer, Bikaner, Jodhpur, Churu and Nagpur), Gujarat (Kutch region), Marginal areas in Punjab and Haryana.
• It is a ripple ground covered with Sand Dunes, locally known as Dhrian.

 

Key Facts:

• ‘Mushroom rock’ can be found in Thar desert.
• Sandy soils, saline and poor in organic content.
• Area underlain by quartzite, schist, and gneiss, covered by aeolian (wind-blown) sand.

 

Coastal Plains

Coastal plains have been formed due to the erosion and deposition of the Oceanic waves and the deposition brought down by the Peninsular plateau. The Indian coastal plain is divided into two parts;

1. Western Coastal Plains.
2. Eastern Coastal Plains.

Western Coastal Plain

• Lies between the Western Ghats and the Arabian Sea.
• Extends from Rann of Kachchh (Gujarat) to Kanyakumari (Tamil Nadu).
• States covered: Gujarat, Maharashtra, Goa, Karnataka, Kerala.
• The average width of the plains is 65 km. In the mouth of the Narmada and Tapi river its width is 82 km.
• Western Coastal plain is an example of Submerged Coastal plain.
• Western Coastal plain is divided into 4 sub-divisions;
  • Kathiwar plain:
  • Konkon plain:
  • Karnataka plain:
  • Malabar plain:

 

Eastern Coastal Plains

• Lies between the Eastern Ghats and the Bay of Bengal.
• Extends from Subarnarekha River (Odisha) to Kanyakumari.
• States covered: West Bengal, Odisha, Andhra Pradesh, Tamil Nadu, Puducherry.
• The northern part is referred to as the Northern Circar ( ), while the central part is known as Golkunda the southern part is known as the Coromondal Coast.
• Eastern coastal plain is an example of Emergent coastal plain.
• Eastern Coastal plain is divided into 3 sub-divisions;
  • Utkal Plain:
  • Andhra Plain:
  • Coromondal Plain:

 

Key Facts:

• Total coastal states are 9.
• The coastal state with plains is 8 (West Bengal has no coastal plain).
• Malabar Coast is compound coast that showing evidence of both Submergence and Emergence coast.

 

Islands of India

India has more than 1,200 islands, mostly grouped into two major archipelagos, one is Andaman and Nicobar Islands in the Bay of Bengal and another is Lakshadweep Islands in the Arabian Sea. Other significant island groups and isolated islands are located along the eastern and western coasts and near river mouths.

 

Andaman and Nicobar Islands

• Andaman and Nicobar Island were formed due to collision between Indian plate and Burma minor plate. (Part of Eurrasian plate).
• Located in the Bay of Bengal, extending from 6°N to 14°N latitude to 92°E to 94°E longitude.
• This Archipelago is composed of 223 big and small Island (204 Andaman Island + 19 Nicobar Island).
• Andaman and Nicobar Islands is a Union Territory with three districts: North & Middle Andaman, South Andaman, Nicobar.
• Andaman Island consist of 4 major Islands called North Andaman, Middle Andaman, South Andaman, and Little Andaman. (North Andaman, Middle Andaman, and South Andaman together called as Great Andaman)
• Capital: Sri Vijaya Puram (previously known as Port Blair), located in South Andaman.
• Andaman and Nicobar Islands are separated by the 10° Channel. (Between Little Andaman and Car Nicobar).
• Andaman Island is the home to India’s only active Volcano: Barren Island is the only active volcano in India, located on Andaman Sea. Another Island, Narcondam Island is made up of volcanic eruption, located in North Andaman Sea.
• Nicobar Island consist of 3 major Islands called Great Nicobar, Car Nicobar, and Little Nicobar.
• Indira Point (Great Nicobar) is the southernmost tip of India (6°45'N).
• Highest peak of Andaman and Nicobar Island is Saddle Peak (738 m), located at North Andaman.
• Duncan Pass: Connect South Andaman and Little Andaman.

 

Key Facts:

• Andaman & Nicobar Island is a example of Archipelago Island or Volcanic Island.
• Coco Channel: Between North Andaman and Coco Islands (Myanmar).
• Official Language of Andaman and Nicobar Island is Bengali and English.
• Greatest Island of Andaman is Middle Andaman.
• Smallest Island of Andaman is Ross Island (Currently known as Netaji Subhas Chandra Bose Island).
• Greatest Island of Nicobar is Great Nicobar.
• Smallest Island of Nicobar is Pillomillo Island.
• Havelock Island, part of the Andaman & Nicobar Islands, was officially renamed as Swaraj Dweep in December 2018.
• Neil Island renamed as Shaheed Dweep.

 

Lakshadweep Islands

• Located in the Arabian Sea, between 8°N and 12°N latitude.
• Formed by coral atolls and reefs (not volcanic). Surrounded by lagoons and fringing reefs, flat terrain, no hills or streams.
• Lakshadweep means, Hundred Thousand Islands.
• Capital: Kavaratti Island.
• Total islands: 36 (11 inhabited).
• Largest Island of Lakshadweep is Andrott.
• Smallest Island of Lakshadweep is Bitra.
• The 8° Channel is a marine channel located in the Arabian Sea; it lies between Minicoy Island (southernmost island of Lakshadweep) and Maldives. The 8° Channel acts as a maritime boundary between India and the Maldives.

 

Islands in the Bay of Bengal (besides Andaman–Nicobar)

• Sagar Island (West Bengal): Mouth of Hooghly River; site of Gangasagar Mela.
• Sriharikota (Andhra Pradesh): ISRO’s Satish Dhawan Space Centre.
• Wheeler Island (Odisha): Now called APJ Abdul Kalam Island; missile testing.

 

Islands in the Arabian Sea (besides Lakshadweep)

• Diu (part of Dadra & Nagar Haveli and Daman & Diu UT).
• Elephanta Island (Maharashtra): UNESCO World Heritage site (cave temples).
• Salsette Island: Contains Mumbai and Thane.
• Pirotan Island (Gujarat): Marine National Park.

 

Indian Maritime Border with Sri Lanka and Maldives (Adjoining Islands)

 

Indian Maritime Border – Sri Lanka

• India shares a maritime boundary with Sri Lanka in the Palk Strait, Gulf of Mannar, and the Indian Ocean.
• The two countries are separated by a narrow sea stretch of 32 km at the closest point between Dhanushkodi and Talaimannar.
• Pamban Island (India): Connected to mainland Tamil Nadu via the Pamban Bridge.
• Dhanushkodi: Eastern tip of Pamban Island; origin of Ram Setu / Adam’s Bridge.
• Adam’s bridge/Ram Setu: connected Dhanushkodi and Talaimannar.
• Pamban Island is associated with India.
• Manner Island is associated with Srilanka.

 

Indian Maritime Border – Maldives

• India shares its maritime boundary with the Maldives in the southern Arabian Sea.
• Minicoy Island (southernmost in Lakshadweep) lies close to the Maldives. The 8° Channel (or Eight Degree Channel) forms the international marine boundary between India and Maldives.
• Though geographically close, Minicoy is part of India, and its culture shares linguistic and ethnic ties with the Maldives.