In this guide
Stand on the Sam dunes near Jaisalmer at sunset and the Thar seems empty — waves of golden sand stretching to the horizon. But the Thar is, in fact, one of the most densely populated deserts in the world. Villages, herders, farmers and towns have adapted to its extremes for centuries, building water tanks, planting khejri trees, breeding camels and sheep, and creating a rich culture. Today the desert is changing rapidly — with canal irrigation, solar parks and wind farms — and understanding it is central to RAS geography.
Extent
| Feature | Details |
|---|---|
| Name | The Thar, or the Great Indian Desert |
| Total extent | Spread across Rajasthan, parts of Gujarat, Punjab, Haryana, and Sindh (Pakistan) |
| Share in Rajasthan | The larger part of the Indian Thar lies in Rajasthan; the desert covers roughly three-fifths of the state |
| Main districts | Jaisalmer, Barmer, Bikaner, Jodhpur, Churu, Nagaur, Sri Ganganagar, Hanumangarh, and parts of Jalore, Pali, Sikar, Jhunjhunu |
How did the Thar form?
There is no single accepted explanation. Theories include:
- Climate change — a shift to drier conditions after the last glacial period;
- Rain shadow and winds — the Aravallis run parallel to the monsoon winds, and the region lies far from moisture sources;
- Past seas and rivers — the region was once under the sea (the Tethys) and later crossed by rivers such as the ancient Saraswati/Ghaggar, whose drying left sediments;
- Human activity — overgrazing and deforestation are thought to have extended desert conditions in historical times.
Sub-regions
| Sub-region | Character |
|---|---|
| Marusthali | The true desert in the west — shifting dunes, very low rainfall |
| Bagar | Semi-arid zone east of Marusthali, adjoining the Aravallis (Shekhawati, parts of Nagaur and Jalore) |
| Luni basin | Plain drained by the seasonal Luni river — Jodhpur, Barmer, Jalore |
| Ghaggar plain | Northern plain of the Ghaggar — now canal-irrigated (Hanumangarh, Sri Ganganagar) |
| Shekhawati region | Sandy tracts with inland drainage and scattered hills |
Sand dunes
Dunes are the most striking feature of the Thar. Their shape depends on wind direction, wind strength, sand supply and vegetation.
| Dune type | Shape | Where / notes |
|---|---|---|
| Barchan | Crescent-shaped, horns pointing downwind | Common in the western desert; move with the wind |
| Longitudinal (seif) | Long ridges parallel to the wind | Western Jaisalmer and Barmer |
| Parabolic | U-shaped, horns pointing upwind, anchored by vegetation | Common across the desert |
| Transverse | Ridges at right angles to the wind | Where sand supply is large |
| Star | Radiating arms | Where winds come from several directions |
| Shrub-coppice | Small dunes around bushes | Where vegetation traps sand |
Dharian is a local term for shifting dunes in the Jaisalmer region.
Other landforms
- Playas and salt lakes — depressions where water collects and evaporates, leaving salt: Sambhar, Didwana, Pachpadra, Lunkaransar, Kuchaman.
- Rann or tal — local names for low-lying saline or clay flats.
- Inland drainage — many streams disappear into the sand instead of reaching the sea.
Climate
- Rainfall — less than 25 cm a year in the west (below 10 cm in parts of Jaisalmer), rising to about 40–50 cm on the eastern margin.
- Temperature — very hot summers (the highest temperatures in India, above 50°C at places such as Phalodi) and cold winter nights.
- Winds — dust storms (andhi) in summer; hot winds (loo).
- Drought — frequent and severe.
Life in the Thar
| Aspect | Adaptations |
|---|---|
| Vegetation | Khejri (Prosopis cineraria — the state tree), rohida, ker, babool, phog; grasses such as sewan |
| Wildlife | Great Indian Bustard (state bird), chinkara (state animal, wild category; the camel has been the state animal in the livestock category since 2014), blackbuck, desert fox, and migratory birds |
| Livestock | Camels, sheep, goats; pastoralism is central |
| Water | Tankas, kundis, beris, nadis and khadins to harvest rain (see our post on water harvesting) |
| Housing | Circular huts with thick mud walls and thatched roofs to keep interiors cool |
Protected areas
The Desert National Park near Jaisalmer and Barmer protects dune ecosystems and the critically endangered Great Indian Bustard, along with fossil sites such as the Akal Wood Fossil Park (fossilised tree trunks from the Jurassic period).
A changing desert
| Change | Effect |
|---|---|
| Indira Gandhi Canal | Brought irrigation to the northern and western desert; farming expanded; but waterlogging and salinity appeared in places |
| Solar and wind energy | Huge parks at Bhadla (Jodhpur), Jaisalmer and Bikaner; jobs and revenue, but also land-use conflicts and threats to birds (power-line collisions for the Great Indian Bustard) |
| Mining and oil | Barmer oil fields; lignite; gypsum |
| Roads and towns | Improved connectivity; urban growth |
Desertification
The Thar faces land degradation from overgrazing, wind erosion, loss of vegetation and poor water management. Responses include shelterbelts, sand-dune stabilisation, controlled grazing and research by the Central Arid Zone Research Institute (CAZRI), Jodhpur. See our post on soils and desertification.
Practice
Prelims-style:
- What is the state tree of Rajasthan?
- Which type of dune is crescent-shaped?
- Name three salt lakes of the Thar.
- Which national park protects the Great Indian Bustard?
- Which institute in Jodhpur researches arid zones?
Mains-style (50 words): What are barchan dunes?
Mains-style (100 words): "The Thar is a desert in transformation." Discuss with reference to canals and renewable energy.
A note on dates and numbers. Exam patterns, vacancies and schedules change from year to year. Always confirm the current details in the latest notification on the Rajasthan Public Service Commission website .
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