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Predicted Questions with Model Answers
Q1 (5 marks — 50 words)
What are Western Disturbances? Explain their origin and agricultural significance for Rajasthan.
Model Answer (EN): Western Disturbances are extratropical cyclones originating over the Mediterranean Sea, carried eastward by mid-latitude westerly jet streams. They bring winter rainfall (Mawat/Mahawat, 1–5 cm per event, 4–8 events per season) to northern Rajasthan — Ganganagar, Sikar, Jhunjhunu. This moisture is critical for rabi crops: wheat, mustard, and gram. Without Mawat, rabi yields decline sharply.
Q2 (5 marks — 50 words)
Name the climatic zones of Rajasthan and the rainfall received in each zone.
Model Answer (EN): Rajasthan has five climatic zones: (1) Arid — western desert (< 25 cm annual rainfall); (2) Semi-arid — central-western (25–50 cm); (3) Sub-humid — central-eastern (50–75 cm); (4) Humid — southeastern (75–100 cm); (5) Very Humid — Jhalawar/Banswara/Dungarpur (> 100 cm). Mount Abu (Sirohi) receives the highest rainfall (~1,500 mm), while Jaisalmer receives the least (~10 cm).
Q3 (5 marks — 50 words)
Why does western Rajasthan experience very high diurnal temperature range? Name the meteorological phenomenon responsible.
Model Answer (EN): Western Rajasthan (Thar Desert) experiences a diurnal temperature range of 20–30°C because sandy soils have low heat capacity and conductivity — they heat rapidly in the day and lose heat quickly at night (strong nocturnal radiation cooling). Absence of cloud cover and low humidity intensify this pattern. Phalodi holds India's all-time maximum temperature record of 51°C (May 19, 2016).
Q4 (5 marks — 50 words)
What is the Aravalli's role in controlling rainfall distribution across Rajasthan?
Model Answer (EN): The Aravalli Range runs southwest-northeast, nearly parallel to the Bay of Bengal monsoon winds. This orientation means the range offers little obstruction to moisture-laden winds, allowing the Thar Desert to remain dry while Mount Abu (perpendicular to moist westerly winds) receives 1,500+ mm. Eastern Rajasthan receives more rainfall (50–100 cm) as winds lose moisture over the plains after crossing the Aravallis.
Q5 (10 marks — 150 words)
The Aravalli Range has been called the 'climatic and ecological lifeline' of Rajasthan. Discuss its role in rainfall distribution, desertification prevention, and recent policy developments.
Model Answer (EN): The Aravalli Range, one of the world's oldest fold mountains (~2,500 million years), extends 692 km through Rajasthan and performs irreplaceable climatic and ecological functions.
Rainfall Distribution: The southwest-northeast orientation of the Aravalli is nearly parallel to Bay of Bengal monsoon winds, so the range does not act as a major barrier to rainfall. However, it creates a windward-leeward effect along its length — Mount Abu, which is perpendicular to moist winds from the Arabian Sea, receives over 1,500 mm annually. Eastern Rajasthan (50–100 cm) receives substantially more rainfall than the Thar Desert west of the range (< 25 cm). Without the Aravalli, monsoon rains would penetrate even less into western Rajasthan.
Desertification Prevention: The Aravalli acts as a natural windbreak preventing the Thar Desert from advancing into the fertile plains of Haryana and Delhi. Scientific studies show that deforestation of Aravalli hillocks has already allowed desert sands to migrate up to 35 km into Haryana since the 1970s. The range hosts scrub forests and grasslands critical for maintaining albedo and soil moisture.
Recent Policy Developments: In January 2026, MoEFCC notified an Eco-Sensitive Zone around Kumbhalgarh Wildlife Sanctuary (243 sq km, 94 villages, Udaipur-Pali-Rajsamand), officially recognising the Aravalli's role as a "critical ecological barrier." A December 2025 Supreme Court stay on its own November 2025 judgment (which protected only 1,048 of 12,081 Aravalli hills under a 100-metre criterion) raised fears of increased mining. Combined, these legal and policy actions reflect growing recognition that the Aravalli's ecological health is inseparable from Rajasthan's climate and water security.
Q6 (10 marks — 150 words)
Describe the impact of climate change on the Thar Desert's ecology and agriculture in Rajasthan, citing recent data and government responses.
Model Answer (EN): Climate change is producing measurable and accelerating impacts on Rajasthan's Thar Desert, disrupting both ecology and agricultural systems.
Observed Temperature Trends: Mean temperatures in Rajasthan have risen by approximately 0.5°C over the past 50 years. Heat wave frequency is increasing — Phalodi recorded 51°C on May 19, 2016, India's all-time maximum. IMD (2026) projects that >50°C events, currently once-per-decade, may occur once every 3–5 years by 2040. The IQAir 2025 Report identified Thar Desert dust storms as a major source of PM2.5 pollution across Bikaner, Jodhpur, and Jaipur (30–40 dust storms annually).
Monsoon Disruption: Southwest monsoon onset variability has increased. The Thar Desert receives 80–90% of its rainfall in June–September; delayed or deficient monsoons directly cause agricultural distress. Extended droughts (classified when rainfall is <75% of normal) are becoming more frequent in western Rajasthan.
Ecological Impacts: The Great Indian Bustard (GIB), already critically endangered (<150 individuals), faces accelerating habitat loss as increasing aridity shrinks its grassland habitat in the Thar. Desertification of the semi-arid zone is advancing, as documented by CAZRI (Central Arid Zone Research Institute, Jodhpur). Sand dune mobility has increased in unplanted areas.
Agricultural Impacts: Rabi crop yields (wheat, mustard) suffer during heat waves during grain-filling stages. Kharif crops face erratic rainfall; groundwater is depleting due to over-irrigation. The state's Rajasthan Action Plan on Climate Change (RAPCC) and PM Fasal Bima Yojana provide policy responses, but adaptation of farming practices (crop switching, drip irrigation, heat-tolerant varieties) remains critical for long-term food security.