Climate – Case-based Questions with Answers

CBSE Class 9 Geography — Chapter 4 Climate — 20 Case-Based Q&A

Class: CBSE Class 9

Subject: Social Science — Geography

Chapter: 4 — Climate

Geography: Contemporary India – I — Chapter 4: Climate

20 case-based questions (10 case passages × 2 questions) with clear, NCERT-aligned answers for CBSE Class 9 exam practice. Topic-wise and exam-oriented.

CBSE Board Focus

Apply concepts to real-life scenarios
Interpret monsoon, seasons and rainfall distribution
Practice concise, structured answers for case-based questions

Content Bank — Topics

Case 1 — Interpreting Climate vs Weather Topic: Concept of Climate

A farmer in Kerala noted that while it was raining heavily one week (affecting his daily labour), the overall pattern of wet summers and dry winters remained unchanged over several decades, guiding his crop choices.

1(a). Distinguish between 'weather' and 'climate' using the farmer's observation.

Answer: Weather refers to the short-term heavy rain that affected the farmer that week. Climate refers to the long-term pattern (wet summers, dry winters) that guides his choice of crops; climate is an average over many years.

1(b). How can long-term climate data help this farmer plan better?

Answer: Long-term climate data informs expected monsoon arrival, rainfall amounts and dry spells, allowing the farmer to select suitable crops (e.g., paddy for monsoon), schedule sowing, and plan irrigation or water storage.

Case 2 — Latitude and Temperature Gradient Topic: Latitude

A school project compared temperature recordings from Kanyakumari (south) and Amritsar (north). Kanyakumari showed smaller seasonal temperature changes, whereas Amritsar had very hot summers and very cold winters.

2(a). Explain why Kanyakumari experiences less seasonal temperature variation than Amritsar.

Answer: Kanyakumari is closer to the equator (low latitude) and receives more direct sunlight year-round, leading to smaller temperature swings. Amritsar, at higher latitude, experiences greater variation due to slanted solar rays in winter and stronger seasonal contrast.

2(b). Name one implication of this latitudinal difference for vegetation or agriculture.

Answer: Tropical crops like coconut and cashew thrive in southern low-latitude regions, while temperate crops (wheat) suit northern areas with colder winters.

Case 3 — Altitude Effects Topic: Altitude

Tourists often visit hill stations like Shimla and Ooty during summer to escape the heat. Local authorities note lower temperatures and occasional snowfall in high-altitude areas.

3(a). Explain why hill stations are cooler than the nearby plains.

Answer: Temperature decreases with altitude (approx. 6.5°C per 1000 m). Hill stations are at higher elevations, so they receive less solar heating and have cooler climates than nearby low-lying plains.

3(b). How does altitude influence rainfall patterns in mountainous regions?

Answer: Mountains force moist air to rise; as it rises it cools and condenses, causing orographic rainfall on windward slopes while creating drier leeward rain-shadow areas.

Case 4 — Monsoon Onset and Pressure Differences Topic: Pressure & Winds

In May, the Indian landmass heats up strongly, creating a low-pressure area. By early June, moist winds from the Arabian Sea reach Kerala and heavy rains begin.

4(a). Explain the role of differential heating of land and sea in the monsoon onset.

Answer: Land heats faster than sea, producing low pressure over the heated land and relatively higher pressure over the cooler ocean. Air moves from sea to land, bringing moisture-laden winds (southwest monsoon) that cause rain.

4(b). Why does the monsoon wind carry moisture?

Answer: Winds passing over warm ocean surfaces pick up water vapour through evaporation; these moisture-laden winds condense over land when cooled, producing rainfall.

Case 5 — Arabian Sea & Bay of Bengal Branches Topic: Distribution of Rainfall

The west coast (Konkan) receives heavy rainfall early in monsoon, while northeastern India also experiences intense rains. Farmers in the Deccan plateau often wait for the monsoon to progress inland.

5(a). How do the Arabian Sea and Bay of Bengal branches differ in the regions they affect?

Answer: The Arabian Sea branch hits the west coast (Konkan) causing heavy rainfall along Western Ghats; the Bay of Bengal branch moves northwards to the northeast and eastern plains causing heavy rain there and later turns inland to affect the Gangetic plains.

5(b). Why does the Deccan plateau receive less rainfall than the west coast?

Answer: The Western Ghats cause orographic lifting on the windward side (west coast) leading to heavy rain, while the leeward Deccan plateau lies in the rain-shadow and receives less rainfall as air descends and loses moisture.

Case 6 — Seasonal Impact on Farming Topic: Seasons

A farmer in Punjab times wheat sowing to the end of the cold season and relies on the retreating monsoon/irrigation for rabi crops. During hot season, water demand increases for crops.

6(a). Explain why wheat is sown after the cold season in northern India.

Answer: Wheat requires cool growing conditions; sowing after early winter ensures it benefits from winter moisture and cool temperatures for vegetative growth before harvest in spring.

6(b). How does the hot season affect irrigation demands?

Answer: High temperatures increase evapotranspiration, raising water demand for crops; hence irrigation needs rise during the hot pre-monsoon season.

Case 7 — Nor'westers in Eastern India Topic: Seasons / Local Weather

In April–May, eastern India experiences violent thunderstorms called nor'westers which bring sudden heavy rain and strong winds, sometimes damaging crops.

7(a). What causes nor'westers and why are they frequent before monsoon?

Answer: Intense heating creates instability; warm moist air rises rapidly causing convective storms (nor'westers). They occur before monsoon when land heats up but monsoon winds haven’t fully arrived.

7(b). Suggest two measures farmers can take to minimise crop damage from nor'westers.

Answer: Use wind-resistant planting patterns, timely harvesting of vulnerable crops, and maintain protective structures (shade nets); ensure efficient drainage to avoid waterlogging after heavy downpours.

Case 8 — Thar Desert and Rain-shadow Effect Topic: Distribution of Rainfall

Western Rajasthan receives very low rainfall compared to the Konkan coast despite being relatively close to the Arabian Sea.

8(a). Explain why western Rajasthan is arid even though it is not very far from the sea.

Answer: The Western Ghats and Aravalli ranges block and reduce moisture-laden winds reaching inland; the region lies in the leeward rain-shadow with high evaporation rates, causing aridity.

8(b). Name one adaptation used by people in arid regions to conserve water.

Answer: Rainwater harvesting structures (johads, check dams), use of drip irrigation and storing monsoon runoff in underground tanks are common adaptations.

Case 9 — Cherrapunji & Mawsynram Topic: Distribution of Rainfall

Cherrapunji and Mawsynram receive some of the highest annual rainfall in the world due to their position relative to the Bay of Bengal branch and local hills.

9(a). Why do these places receive extremely heavy rainfall?

Answer: Moist Bay of Bengal winds are funneled into the Khasi-Jaintia hills where they rise rapidly; orographic uplift leads to intense condensation and heavy rainfall in these hill regions.

9(b). How does very heavy rainfall affect infrastructure and agriculture in these areas?

Answer: It causes soil erosion, landslides, damage to roads/housing; while high moisture supports lush vegetation but challenges crop choices and requires terrace farming and soil-conservation measures.

Case 10 — Monsoon and National Economy Topic: Monsoon as a Unifying Bond

A weak monsoon year leads to lower agricultural output, rising food prices and pressure on rural incomes — affecting demand across the country.

10(a). Explain how a weak monsoon can impact the national economy.

Answer: Reduced crop yields lower rural incomes, decrease purchasing power, raise food inflation, and can slow GDP growth given agriculture's linkage to other sectors; it increases demand for government relief and may strain fiscal resources.

10(b). Give two policy measures the government can adopt to reduce vulnerability to poor monsoon years.

Answer: Implement crop insurance schemes and invest in water infrastructure (reservoirs, groundwater recharge); promote drought-resistant crops and strengthen early-warning systems.