Topic 83: Physiography, Rivers and Lakes of Raj.

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Paper II

Unit 3

Reading Time 49 min read

1. Rajasthan covers 3,42,239 sq km (10.41% of India's land area), the largest state in India by area.
2. Four physiographic divisions: Western Sandy Plain (61.11%), Aravalli Range (9.3%), Eastern Plains (23.0%), South-Eastern Plateau/Hadoti (6.6%).
3. Aravalli Range — world's oldest fold mountains (Pre-Cambrian era, ~2,500 million years old), extends 692 km within Rajasthan; highest peak Guru Shikhar (1,722 m), Mount Abu (Sirohi).
4. Thar Desert (थार मरुस्थल) covers ~61% of Rajasthan's area; average annual rainfall below 25 cm; sand dunes (धोरे) most characteristic landform.
5. Luni (लूनी) — longest river in western Rajasthan (495 km), originates near Pushkar (Ajmer), drains into Rann of Kutch; called "Salt River" as its water turns brackish below Balotra.
6. Chambal (चंबल) — longest river flowing through Rajasthan (966 km total), originates in Janapav Hill (MP); the only perennial river with ravine badlands (बीहड़) in Kota-Sawai Madhopur belt.
7. Banas (बनास) — longest river entirely within Rajasthan (480 km), originates from Khamnor hills (Rajsamand), meets Chambal at Rameshwar Ghat (Sawai Madhopur).
8. Inland drainage (आंतरिक प्रवाह) covers ~60% of Rajasthan — rivers like Ghaggar, Kakni (Luni's tributary), Kantli, and Saraswati (dry) lose water to sand before reaching sea.
9. Sambhar Lake (साम्भर झील) — India's largest inland saltwater lake (240 sq km); Ramsar site; produces ~2.5 lakh tonnes of salt annually; Jaipur–Nagaur–Ajmer tri-junction.
10. Jaisamand Lake (जयसमंद झील) — historically Asia's second-largest artificial lake; built 1685-91 by Maharana Jai Singh; area ~87 sq km; Udaipur district.
11. Indira Gandhi Nahar Pariyojana (IGNP) — 649 km main canal from Harike (Punjab) barrage; world's largest canal irrigation project; transforms Thar Desert; Stage I (204 km) and Stage II (445 km).
12. Chambal Valley Development Project — three dams: Gandhi Sagar (MP), Rana Pratap Sagar (Rawatbhata, Chittorgarh), Jawahar Sagar; total installed capacity ~386 MW.
13. The Aravalli acts as the main watershed divide: rivers west of it drain into the Arabian Sea (or inland), rivers east drain into the Bay of Bengal via the Ganga-Yamuna system.
14. Pushkar Lake (पुष्कर झील) — only lake in India associated with Lord Brahma; freshwater; Ajmer district; unique sacred geography.
15. Nakki Lake (नक्की झील) — highest altitude lake in Rajasthan (~1,200 m); Mount Abu, Sirohi; reportedly carved by fingernails (नख) of gods in Hindu mythology. / नक्की झील — राजस्थान की सबसे ऊँची झील (~1,200 मीटर); माउंट आबू, सिरोही। ---

CORE Key Points at a Glance

1
Rajasthan covers 3,42,239 sq km (10.41% of India's land area), the largest state in India by area.
2
Four physiographic divisions: Western Sandy Plain (61.11%), Aravalli Range (9.3%), Eastern Plains (23.0%), South-Eastern Plateau/Hadoti (6.6%).
3
Aravalli Range — world's oldest fold mountains (Pre-Cambrian era, ~2,500 million years old), extends 692 km within Rajasthan; highest peak Guru Shikhar (1,722 m), Mount Abu (Sirohi).
4
Thar Desert (थार मरुस्थल) covers ~61% of Rajasthan's area; average annual rainfall below 25 cm; sand dunes (धोरे) most characteristic landform.
5
Luni (लूनी) — longest river in western Rajasthan (495 km), originates near Pushkar (Ajmer), drains into Rann of Kutch; called "Salt River" as its water turns brackish below Balotra.
6
Chambal (चंबल) — longest river flowing through Rajasthan (966 km total), originates in Janapav Hill (MP); the only perennial river with ravine badlands (बीहड़) in Kota-Sawai Madhopur belt.
7
Banas (बनास) — longest river entirely within Rajasthan (480 km), originates from Khamnor hills (Rajsamand), meets Chambal at Rameshwar Ghat (Sawai Madhopur).
8
Inland drainage (आंतरिक प्रवाह) covers ~60% of Rajasthan — rivers like Ghaggar, Kakni (Luni's tributary), Kantli, and Saraswati (dry) lose water to sand before reaching sea.
9
Sambhar Lake (साम्भर झील) — India's largest inland saltwater lake (240 sq km); Ramsar site; produces ~2.5 lakh tonnes of salt annually; Jaipur–Nagaur–Ajmer tri-junction.
10
Jaisamand Lake (जयसमंद झील) — historically Asia's second-largest artificial lake; built 1685-91 by Maharana Jai Singh; area ~87 sq km; Udaipur district.
11
Indira Gandhi Nahar Pariyojana (IGNP) — 649 km main canal from Harike (Punjab) barrage; world's largest canal irrigation project; transforms Thar Desert; Stage I (204 km) and Stage II (445 km).
12
Chambal Valley Development Project — three dams: Gandhi Sagar (MP), Rana Pratap Sagar (Rawatbhata, Chittorgarh), Jawahar Sagar; total installed capacity ~386 MW.
13
The Aravalli acts as the main watershed divide: rivers west of it drain into the Arabian Sea (or inland), rivers east drain into the Bay of Bengal via the Ganga-Yamuna system.
14
Pushkar Lake (पुष्कर झील) — only lake in India associated with Lord Brahma; freshwater; Ajmer district; unique sacred geography.
15
Nakki Lake (नक्की झील) — highest altitude lake in Rajasthan (~1,200 m); Mount Abu, Sirohi; reportedly carved by fingernails (नख) of gods in Hindu mythology. / नक्की झील — राजस्थान की सबसे ऊँची झील (~1,200 मीटर); माउंट आबू, सिरोही।

PREDICTED Predicted RAS Questions

Based on PYQ trends and 2026 syllabus analysis

1 5M Name the three drainage divisions of Rajasthan and give one major river system in each. 5 marks · 50 words

Model Answer

Rajasthan has three drainage divisions: (1) Bay of Bengal drainage — Chambal-Banas system (eastern Rajasthan); (2) Arabian Sea drainage — Luni river system (southwestern Rajasthan); (3) Inland drainage — Ghaggar and Kantli rivers (northern Rajasthan, terminating in Thar Desert sands). The Aravalli Range acts as the primary watershed separating these systems.

~50 words • 5 marks

CORE Key Points at a Glance

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PREDICTED Predicted RAS Questions