The Great Indian Desert is also known as the Thar Desert.
It is one of the major physiographic divisions of India.
A desert is an arid or semi-arid region where rainfall is very low, evaporation is high, and vegetation is sparse.
In Indian geography, a desert is also called Marusthal, meaning a dry or dead land.
The Thar Desert forms the westernmost part of India’s great plains and lies mainly in Rajasthan.
Table of Contents
Location Of The Thar Desert
The Great Indian Desert is located to the north-west of the Aravalli Hills.
In India, it is mostly spread across Rajasthan, but it is also present in parts of:
- Gujarat
- Punjab
- Haryana
A part of the desert also extends into Pakistan.
The chapter states that about 85 per cent of the Thar Desert lies in India, while the remaining part lies in Pakistan.
Global Position Of Thar Desert
The Thar Desert is:
- The 17th largest desert in the world.
- The 9th largest hot subtropical desert in the world.
This makes it an important desert region not only in India but also in world geography.
Size And Extent
The Thar Desert stretches approximately:
- 650 Km in length.
- 250 to 300 Km in width.
Its eastern segment extends up to the Aravalli range and forms a semi-arid plain known as the Rajasthan Bagar region.
Climate Of The Thar Desert
The Thar Desert has an arid and semi-arid climate.
It receives only about 150 mm rainfall in a year.
Due to low rainfall and high evaporation, vegetation cover is very low.
This is why the region is known as Marusthali.
Main Climatic Features
- Very low rainfall.
- High evaporation.
- Sparse vegetation.
- Dry winds.
- High temperature during summer.
- Water scarcity.
Topography Of The Thar Desert
The Thar Desert has an undulating topography.
It is dotted with:
- Longitudinal dunes.
- Barchan dunes.
- Sandy plains.
- Playas.
- Saline lakes.
- Seasonal streams.
- Mushroom rocks.
Most of the desert surface is covered by sand plains and sand dunes.
Bagar Region
The semi-arid region of the Thar Desert is called Bagar.
It lies mainly along the eastern part of the desert, close to the Aravalli region.
Features Of Bagar
- It is semi-arid.
- It receives slightly better rainfall than the core desert.
- It has short seasonal streams.
- It supports agriculture in some fertile patches.
- It acts as a transition between the desert and more fertile plains.
Seasonal Streams In Bagar
The Bagar region has many short seasonal streams.
These streams usually originate from the Aravalli region.
Because rainfall is low and the land is sandy, most streams do not reach the sea.
They either disappear into the sand or drain into lakes and playas.
Rohi
Some fertile lands are found in the Bagar region.
These fertile patches are called Rohi.
Rohi areas are important because they support limited agriculture in an otherwise dry region.
Importance Of Rohi
- It supports cultivation in semi-arid areas.
- It is associated with seasonal streams.
- It provides local agricultural value.
- It helps sustain rural settlement in the desert margins.
Luni River
The Luni River is the only large river in this region.
Most other rivers are small and seasonal.
The Luni is important because it represents the main drainage feature of the Thar Desert region.
Inland Drainage
Due to low rainfall and sandy terrain, many streams in the Thar Desert disappear before reaching the sea.
This is called inland drainage.
In this system, water may drain into:
- Lakes.
- Playas.
- Saline depressions.
- Sandy basins.
The lakes and playas often contain brackish water.
They are also important sources of salt.
Playas In The Thar Desert
Playas are flat, dry lake beds found in arid and semi-arid regions.
They form when temporary lakes are filled by occasional rainfall.
Since evaporation is very high in deserts, the water quickly evaporates.
After evaporation, fine sediments such as salt, sand and mud are left behind.
Features Of Playas
- Flat and dry lake beds.
- Found in arid and semi-arid areas.
- Formed by temporary lakes.
- Water evaporates quickly.
- Fine sediments remain after evaporation.
- Salt deposits may form a hard crust.
The salt crust formed after evaporation is sometimes called an alkali flat.
Saline Lakes In The Thar Region
The eastern edge of the Thar Desert has several saline lakes.
Important examples include:
- Sambhar
- Didwana
- Degana / Degara
- Kuchaman
- Sargol
- Khatu
These lakes are important for salt production and local geography.
Geomorphic Landforms In The Thar Desert
The Thar Desert has several important geomorphic landforms formed mainly by wind action and physical weathering.
Important landforms include:
- Barchan dunes.
- Longitudinal dunes.
- Mushroom rocks.
- Sand plains.
- Playas.
- Oasis.
Sand Dunes
Most of the Thar Desert is covered by sand plains and sand dunes.
Sand dunes are formed by the action of wind.
There are two main types of sand dunes mentioned in the chapter:
- Barchan dunes.
- Longitudinal dunes.
Barchan Dunes
Barchan dunes are crescent-shaped or half-crescent-shaped sand dunes.
They are found in large areas of the Thar Desert.
These dunes are formed where wind blows mainly from one direction and sand supply is limited.
Longitudinal Dunes
Longitudinal dunes are long, narrow sand ridges.
They are mostly found along the India-Pakistan border.
These dunes are aligned with the direction of the prevailing wind.
Dhriyan
The shifting sand dunes of the Thar Desert are locally known as Dhriyan.
This is an important term for exams.
Mushroom Rocks
Chhatra or mushroom rocks are important geomorphological features of the Thar Desert.
They are formed by wind erosion.
The lower part of the rock is eroded more strongly by sand-laden winds, while the upper part remains broader.
This gives the rock a mushroom-like shape.
Oasis
An oasis is also found in the southern part of the Thar Desert.
An oasis is a fertile patch in a desert where water is available.
It supports vegetation and settlement in an otherwise dry region.
Flora Of The Great Indian Desert
The flora of the Thar Desert consists mainly of drought-resistant plants.
These plants can survive with very little water.
Important desert plants include:
- Khejri
- Acacia
- Cacti
- Dhok
- Ronj
- Salai
- Sewan grass
These plants are adapted to dry conditions through deep roots, small leaves, thorny structures and water conservation.
Importance Of Desert Flora
Desert plants are important because they:
- Prevent soil erosion.
- Provide fodder.
- Support local wildlife.
- Help stabilise sand dunes.
- Support desert ecology.
Fauna Of The Great Indian Desert
The Thar Desert supports many animals adapted to arid conditions.
Important animals include:
- Blackbuck
- Chinkara
- Indian wild ass
- Great Indian Bustard
The Great Indian Bustard is critically endangered and is one of the most important species of the desert ecosystem.
Desert National Park
The Desert National Park is an important protected area in the Thar Desert.
It supports a wide range of desert plants and animals.
It is especially significant for:
- Birds.
- Reptiles.
- Desert mammals.
- Great Indian Bustard habitat.
Mineral And Resource Importance
The chapter describes the Thar Desert as a very resource-rich desert.
It mentions minerals such as:
- Gypsum
- Kaolin
- Lignite coal resources
The desert houses one of the world’s large lignite coal resources.
This makes the region important not only physically but also economically.
Geological History Of The Thar Desert
The underlying rock structure of the Thar Desert is part of the Peninsular Plateau.
However, due to extreme arid conditions, the surface features have been shaped mainly by:
- Physical weathering.
- Wind action.
- Desert erosion.
- Sand deposition.
Marine Past Of The Thar Desert
During the Mesozoic Era, the landmass of the Thar Desert was under the sea.
Evidence of this marine submergence includes:
- Wood fossils at Aakal.
- Marine deposits around Brahmsar near Jaisalmer.
These show that the region has a long and complex geological history.
Age Of The Thar Desert
The origin of the Thar Desert is debated.
Some scholars consider it to be approximately 4,000 to 10,000 years old.
Others consider its origin to be around 1500 to 2000 BC.
This shows that the present desert landscape is relatively recent in geological terms.
Slope And Orientation Of The Thar Desert
On the basis of slope, the Thar Desert can be divided into two parts:
- Northern part.
- Southern part.
Northern Slope
The northern part of the Indian desert slopes towards Sindh.
Southern Slope
The southern part of the Indian desert slopes towards the Rann of Kutch.
This slope pattern influences drainage, surface water movement and the formation of salt lakes and playas.
Thali Or Sandy Plain
The area north of the Luni River is called Thali or the sandy plain.
This area is dominated by sand and desert landforms.
It forms an important part of the western desert landscape.
Transition Towards Punjab And Haryana Plains
To the east and north-east of the Great Indian Desert lie the fertile plains of Punjab and Haryana.
The eastern boundary of this plain in Haryana is marked by the Yamuna River.
Some parts of the plain show flat to slightly convex topography due to the subsurface Delhi-Aravalli ridge.
Importance Of The Great Indian Desert
The Thar Desert is important in Indian geography for several reasons.
- It forms a major arid region of India.
- It shows classic desert landforms such as dunes, playas and mushroom rocks.
- It supports drought-resistant vegetation.
- It has unique desert wildlife.
- It contains saline lakes and salt-producing areas.
- It has mineral and lignite resources.
- It influences settlement, agriculture and water use in western India.
- It forms an important border landscape between India and Pakistan.
Important Facts At A Glance
| Topic | Fact |
|---|---|
| Other name | Thar Desert |
| Indian term | Marusthal |
| Global rank | 17th largest desert |
| Hot subtropical desert rank | 9th largest |
| Location | North-west of Aravalli Hills |
| Main Indian state | Rajasthan |
| Also present in | Gujarat, Punjab and Haryana |
| Share in India | About 85 per cent |
| Annual rainfall | About 150 mm |
| Semi-arid region | Bagar |
| Fertile patches | Rohi |
| Only large river | Luni |
| Area north of Luni | Thali or sandy plain |
| Main drainage type | Inland drainage |
| Important landforms | Dunes, playas, mushroom rocks, oasis |
| Barchan dunes | Crescent-shaped dunes |
| Longitudinal dunes | Common near India-Pakistan border |
| Shifting dunes | Dhriyan |
| Important flora | Khejri, acacia, cacti, dhok, ronj, salai, sewan grass |
| Important fauna | Blackbuck, chinkara, Indian wild ass, Great Indian Bustard |
| Protected area | Desert National Park |
| Geological base | Part of Peninsular Plateau |
| Marine evidence | Aakal wood fossils and Brahmsar marine deposits |
| Northern slope | Towards Sindh |
| Southern slope | Towards Rann of Kutch |
FAQs On The Great Indian Desert
What is the Great Indian Desert?
The Great Indian Desert is the Thar Desert, an arid and semi-arid desert region mainly located in western Rajasthan.
What is another name of the Great Indian Desert?
The Great Indian Desert is also called the Thar Desert.
Where is the Thar Desert located?
The Thar Desert is located to the north-west of the Aravalli Hills, mainly in Rajasthan, with extensions into Gujarat, Punjab and Haryana.
How much of the Thar Desert lies in India?
About 85 per cent of the Thar Desert lies in India.
Which country contains the remaining part of the Thar Desert?
The remaining part of the Thar Desert lies in Pakistan.
What is Marusthal?
Marusthal means desert or dead land. It is used for arid and semi-arid regions such as the Thar Desert.
What is the annual rainfall of the Thar Desert?
The Thar Desert receives about 150 mm rainfall in a year.
Why is vegetation sparse in the Thar Desert?
Vegetation is sparse because rainfall is low and evaporation is high.
What is Bagar?
Bagar is the semi-arid region of the Thar Desert.
What is Rohi?
Rohi refers to fertile patches found in the Bagar region.
Which is the only large river in the Thar Desert region?
The Luni River is the only large river in this region.
What is inland drainage?
Inland drainage means water does not reach the sea. Instead, it disappears into sand or drains into lakes, playas or saline depressions.
What are playas?
Playas are flat, dry lake beds found in arid and semi-arid regions. They form when temporary lakes dry up after evaporation.
Which are important saline lakes of the Thar region?
Important saline lakes include Sambhar, Didwana, Degana, Kuchaman, Sargol and Khatu.
What are Barchan dunes?
Barchan dunes are crescent-shaped or half-crescent-shaped sand dunes.
Where are longitudinal dunes mostly found in the Thar Desert?
Longitudinal dunes are mostly found along the India-Pakistan border.
What are Dhriyan?
Dhriyan is the local name for shifting sand dunes in the Thar Desert.
What are mushroom rocks?
Mushroom rocks are desert landforms created by wind erosion, where the lower part of the rock is eroded more than the upper part.
What is an oasis?
An oasis is a fertile area in a desert where water is available.
Which plants are found in the Thar Desert?
Important plants include khejri, acacia, cacti, dhok, ronj, salai and sewan grass.
Which animals are found in the Thar Desert?
Important animals include blackbuck, chinkara, Indian wild ass and the Great Indian Bustard.
Why is Desert National Park important?
Desert National Park is important because it protects desert flora, fauna, birds, reptiles and habitats of the Great Indian Bustard.
What is the geological base of the Thar Desert?
The underlying rock structure of the Thar Desert is part of the Peninsular Plateau.
What evidence shows that the Thar Desert was once under the sea?
Wood fossils at Aakal and marine deposits around Brahmsar near Jaisalmer show earlier marine submergence.
What is Thali?
Thali is the sandy plain north of the Luni River.
What is the slope of the Thar Desert?
The northern part slopes towards Sindh, while the southern part slopes towards the Rann of Kutch.
Last Moment Exam Cheat Sheet – The Great Indian Desert
- Great Indian Desert – Also called Thar Desert.
- Desert – Arid or semi-arid region.
- Marusthal – Desert or dead land.
- Thar Desert rank – 17th largest desert in the world.
- Hot subtropical desert rank – 9th largest.
- Location – North-west of Aravalli Hills.
- Main Indian state – Rajasthan.
- Also found in – Gujarat, Punjab and Haryana.
- Share in India – About 85 per cent of Thar Desert.
- Annual rainfall – Around 150 mm.
- Reason for low vegetation – Low rainfall and high evaporation.
- Marusthali – Name used because of dry desert conditions.
- Bagar – Semi-arid region of Thar Desert.
- Rohi – Fertile patches in Bagar region.
- Luni – Only large river in the region.
- Most rivers – Ephemeral or seasonal.
- Drainage – Inland drainage.
- Playas – Flat dry lake beds in arid and semi-arid regions.
- Brackish lakes and playas – Important source of salt.
- Saline lakes – Sambhar, Didwana, Degana, Kuchaman, Sargol, Khatu.
- Most of Thar – Covered by sand plains and sand dunes.
- Barchan dunes – Crescent-shaped dunes.
- Longitudinal dunes – Mostly found near India-Pakistan border.
- Chhatra / Mushroom rocks – Important desert erosional features.
- Dhriyan – Local name of shifting sand dunes.
- Oasis – Found in southern Thar Desert.
- Flora – Khejri, acacia, cacti, dhok, ronj, salai, sewan grass.
- Fauna – Blackbuck, chinkara, Indian wild ass, Great Indian Bustard.
- Desert National Park – Important for desert flora and fauna.
- Underlying rocks – Part of Peninsular Plateau.
- Surface features shaped by – Physical weathering and wind action.
- Mesozoic Era – Thar landmass was under the sea.
- Marine evidence – Wood fossils at Aakal and marine deposits near Brahmsar, Jaisalmer.
- Age debate – Around 4,000 to 10,000 years old according to some; around 1500 to 2000 BC according to others.
- Northern slope – Towards Sindh.
- Southern slope – Towards Rann of Kutch.
- Thali – Sandy plain north of Luni River.