🌦️ Chapter: India – The Land of Monsoon Climate 📖 Pages: 53–76 | SCERT Kerala Class 9 Social Science II

 

🌦️ Chapter: India – The Land of Monsoon Climate

📖 Pages: 53–76 | SCERT Kerala Class 9 Social Science II

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🧭 CAPSULE NOTES (Detailed Summary)

• India’s Climate: Mostly tropical monsoon, with clear seasonal changes.

• The word ‘monsoon’ comes from the Arabic word ‘mausim’, meaning season.

• Climate of India is influenced by:

  1. Latitude – Tropical location near the equator.

  2. Altitude – Himalayas prevent cold winds.

  3. Distance from sea – Coastal areas have moderate climate; interiors are extreme.

  4. Monsoon winds – Bring seasonal rainfall.

  5. Western disturbances and cyclones.

• The Himalayas:

  • Block cold winds from Central Asia.

  • Force monsoon winds to rise, causing rainfall.

• Arabian Sea & Bay of Bengal:

  • Moisture-laden winds from these seas bring rain.

• Rainfall Distribution:

  • Very heavy: Western Ghats, North-east India.

  • Moderate: Northern plains.

  • Low: Rajasthan, Ladakh.

• Temperature:

  • High in summer, especially in north-western plains.

  • Moderate in coastal regions due to sea breeze.

• Agriculture:

  • Highly dependent on monsoon rainfall.

  • Delay or failure of monsoon causes drought or crop failure.

• Natural Vegetation:

  • Rainfall determines vegetation types:

    • Evergreen forests (heavy rainfall areas)

    • Deciduous forests (moderate rainfall)

    • Thorny bushes (low rainfall)

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🪶 POINTS TO REMEMBER

• India lies in the tropical zone, but climate varies due to relief and monsoon.

• Himalayas play a crucial role in controlling Indian climate.

• Monsoon means seasonal reversal of winds.

• Temperature decreases with increase in latitude and altitude.

• Southwest Monsoon (June–September) → Major rainy season.

• Northeast Monsoon (October–November) → Rain for Tamil Nadu & SE coast.

• Jet Streams affect the onset and withdrawal of monsoons.

• Cyclones form mainly in the Bay of Bengal.

• Western disturbances bring winter rainfall to north India.

• India’s rainfall pattern is uneven and seasonal.

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📗 IMPORTANT DEFINITIONS (Short & Simple)

Term	Definition
Monsoon	Periodic reversal of wind direction causing seasonal rain.
Southwest Monsoon	Winds from Arabian Sea and Bay of Bengal causing heavy summer rain.
Northeast Monsoon	Dry winds from land giving rain to Tamil Nadu coast.
Western Disturbances	Cyclonic storms from the Mediterranean Sea that bring winter rain to north India.
Cyclone	A rotating storm over warm ocean water with strong winds and rain.
Rain Shadow Region	Area on leeward side of hills receiving very little rainfall.
Jet Streams	High-altitude fast-moving winds affecting monsoon timing.
Leeward Side	The side of a mountain sheltered from wind and rain.
Windward Side	The side of a mountain facing the oncoming wind, gets more rain.
Humidity	Amount of moisture present in the air.
Climate	Average weather condition of a place over long period.
Weather	Short-term atmospheric condition of a place.

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💬 ONE-WORD QUESTIONS

1. Type of climate in India – Monsoon climate

2. Place with world’s highest rainfall – Mawsynram

3. Season between March and May – Hot weather season

4. Season between December and February – Cold weather season

5. Winds that bring rain to Tamil Nadu – Northeast monsoon

6. Winds that bring rain to most of India – Southwest monsoon

7. Winter rain in north India – Western disturbances

8. Area receiving very low rainfall – Rajasthan / Ladakh

9. The Arabic meaning of monsoon – Season

10. Moderate climate near sea – Maritime climate

11. Extreme climate in interiors – Continental climate

12. Moisture-bearing winds – Monsoon winds

13. Period of retreat of monsoon – October–November

14. Rainfall in western coast – Orographic rain

15. Winds causing retreating monsoon – Northeast winds

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💡 ONE/TWO-SENTENCE QUESTIONS & ANSWERS

1. Why is India called a land of monsoon climate?
   Because it experiences seasonal reversal of winds and distinct wet and dry periods.

2. What is the importance of the Himalayas in influencing India’s climate?
   They protect India from cold winds of Central Asia and cause rainfall by forcing monsoon winds to rise.

3. Why do western coasts and northeastern states get heavy rainfall?
   Because they are on the windward side of mountains facing the monsoon winds.

4. What is a rain shadow region?
   It is an area on the leeward side of hills receiving very little rainfall.

5. Which winds bring rainfall to India in summer?
   The southwest monsoon winds from Arabian Sea and Bay of Bengal.

6. Which part of India receives rainfall from the northeast monsoon?
   Tamil Nadu and parts of Andhra Pradesh.

7. What are the effects of monsoon on Indian agriculture?
   Adequate monsoon brings good harvest; weak monsoon causes drought and crop failure.

8. Why is rainfall uneven in India?
   Because of varying relief, wind direction, and distance from the sea.

9. How do western disturbances affect Indian climate?
   They bring winter rainfall to Punjab, Haryana, and northern plains, useful for wheat cultivation.

10. What are the main factors determining India’s climate?
    Latitude, altitude, distance from sea, monsoon winds, and relief.

11. Which region receives rainfall twice a year?
    Tamil Nadu — during both southwest and northeast monsoons.

12. Why do coastal areas have moderate climate?
    Because land and sea breezes regulate the temperature.

13. Why is Ladakh a cold desert?
    Due to high altitude and rain shadow effect of the Himalayas.

14. When does India receive maximum rainfall?
    Between June and September during the southwest monsoon.

15. What is the significance of monsoon rains?
    They influence agriculture, water supply, power generation, and vegetation in India.

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🌤️ SEASONS IN INDIA — TABLE SUMMARY

Season	Months	Major Features	Rainfall Source
Cold Weather	Dec–Feb	Low temperature, dry air	Western disturbances
Hot Weather	Mar–May	High temperature, dust storms	Pre-monsoon showers
Southwest Monsoon	Jun–Sep	Heavy rainfall, humid	Arabian Sea & Bay of Bengal winds
Retreating Monsoon	Oct–Nov	Decline in rainfall, cyclones on east coast	Northeast winds

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🪴 EXTRA FACTS & NOTES

• Kerala is the first state to receive monsoon rains (~June 1).

• Monsoon withdrawal starts from northwest India in October.

• Bay of Bengal branch → brings rainfall to eastern India.

• Arabian Sea branch → brings rainfall to western coast and central India.

• Cyclones are frequent in the Bay of Bengal during Oct–Nov.

• Western Ghats cause heavy orographic rain on west coast.

• Rainfall decreases from east to west in northern plains.

• Mawsynram and Cherrapunji – world’s wettest places.

• Thar Desert remains dry due to lack of moisture-bearing winds.

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🧾 VERY SHORT RECAP POINTS

• India = Monsoon climate → Alternate dry & wet seasons.

• Four seasons: Cold, Hot, Southwest Monsoon, Retreating Monsoon.

• Relief, wind, and ocean affect rainfall pattern.

• Himalayas = Climate barrier & rainfall controller.

• Rainfall: Uneven distribution, vital for agriculture.

• Tamil Nadu → Rain from northeast monsoon.

• Rajasthan → Rain shadow region.

• Mawsynram → Highest rainfall.

• Jet streams influence monsoon onset.