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Predicted Questions with Model Answers
Q1 (5 marks — 50 words)
Name the three drainage divisions of Rajasthan and give one major river system in each.
Model Answer (EN): 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.
Q2 (5 marks — 50 words)
What is the Eastern Rajasthan Canal Project (ERCP)? Why was it granted National Project status?
Model Answer (EN): ERCP is a ₹37,247 crore inter-basin water transfer project diverting surplus Chambal-Kalisindh waters northward to 13 eastern Rajasthan districts, benefiting ~2.8 crore people. Granted National Project status in 2023, it qualifies for 90:10 Centre-State funding. The Navnera Barrage on Chambal (Bundi) is its first component, addressing chronic water scarcity in Jaipur and Bisalpur.
Q3 (5 marks — 50 words)
Describe the ecological importance of Sambhar Lake and the conservation challenges it faces.
Model Answer (EN): Sambhar Lake (240 sq km) is India's largest inland saltwater lake and a Ramsar Wetland (1990). It is a critical wintering habitat for flamingos and migratory birds. Key challenges: 2019 mass bird mortality (20,000 birds, botulism); industrial salt production by Hindustan Salts Ltd.; agricultural chemical seepage; tourism pressure; and shrinking water inflows due to groundwater overextraction in the catchment.
Q4 (5 marks — 50 words)
What is the significance of the Aravalli Range as a watershed in Rajasthan?
Model Answer (EN): The Aravalli Range (692 km in Rajasthan, Guru Shikhar 1,722 m) is 2,500 million years old and divides Rajasthan's drainage: west of it, rivers flow toward the Arabian Sea (Luni) or drain inland (Ghaggar); east of it, rivers flow toward the Bay of Bengal (Chambal-Banas). It also controls rainfall distribution — Mount Abu receives the highest annual rainfall (1,500+ mm).
Q5 (10 marks — 150 words)
Critically examine the role of the Indira Gandhi Nahar Pariyojana (IGNP) in transforming the Thar Desert. Also discuss the major ecological problems it has created.
Model Answer (EN): The Indira Gandhi Nahar Pariyojana (IGNP), formerly the Rajasthan Canal, originates from the Harike Barrage on the Sutlej-Beas confluence in Punjab and extends 649 km into the Thar Desert of western Rajasthan. Construction began in 1958; Stage I (204 km) was completed by 1972 and renamed IGNP in 1984.
Positive Transformations: IGNP commands 19.63 lakh hectares, converting barren desert into agricultural land in Ganganagar, Hanumangarh, Bikaner, and Jaisalmer districts. It brought drinking water to chronically arid communities, enabled crop diversification (wheat, cotton, groundnut), and generated rural employment. It is rightly called the "lifeline of western Rajasthan."
Ecological Problems: However, IGNP has created severe ecological disruptions. Seepage from unlined canals has raised the water table from 30m to under 2m in some areas, causing waterlogging on ~1.54 lakh hectares. Secondary soil salinization threatens agricultural productivity. Fragile desert ecosystem — adapted scrub vegetation, migratory bird habitats (especially near Gharana Wetland) — has been disrupted by command-area cultivation. Invasive species (Prosopis juliflora) have colonized canal margins. The 2024-26 HDPE canal lining project (₹3,200 crore) in Jaisalmer-Barmer aims to address seepage losses, but ecosystem restoration remains a long-term challenge requiring integrated land-water management.
Q6 (10 marks — 150 words)
Discuss the major river systems of Rajasthan. How does the Chambal River differ from the Luni River in terms of origin, drainage pattern, and ecological significance?
Model Answer (EN): Rajasthan's rivers are broadly classified into three systems based on their drainage destination: Bay of Bengal, Arabian Sea, and Inland drainage.
Chambal River: Originates from Janapav Hills, Madhya Pradesh (Vindhyan Plateau, 843 m). It is a perennial river entering Rajasthan near Chaurasigarh (Chittorgarh) and forming the Rajasthan-MP boundary for ~250 km. Length in Rajasthan: ~322 km. Major tributaries: Banas, Kali Sindh, Parvati. It joins the Yamuna in UP. The National Chambal Sanctuary (5,400 sq km) hosts gharials (2,541 as of 2024), Gangetic dolphins, and mugger crocodiles — making it ecologically the most significant river in Rajasthan. Kota and Rana Pratap Sagar dams generate hydropower.
Luni River: Originates from Pushkar Valley (Nag Hills, Ajmer). It is an ephemeral (seasonal) river flowing southwest through Marwar — Jodhpur, Barmer, Jalore — to drain into the Rann of Kutch (Gujarat). Length: ~495 km (320 km in Rajasthan). Luni's water is fresh upstream of Balotara (Barmer) but becomes saline downstream due to mineral leaching from arid soils. Major tributaries: Sukri, Jawai, Guhiya. It has no perennial inflow and dries in the non-monsoon season.
Key Differences: Chambal is perennial, Bay of Bengal-bound, ecologically rich, and supports large dams; Luni is ephemeral, Arabian Sea-bound (via Rann), ecologically fragile, and lacks major reservoir infrastructure. Together they represent the hydrological contrast between eastern fertile plains and western arid Rajasthan.