Chapter 16 of G.C. Leong’s Certificate Physical and Human Geography is titled “The Tropical Monsoon and Tropical Marine Climates.” This chapter focuses on regions that experience seasonal shifts in wind patterns and coastal tropical areas influenced by trade winds.
1. Distribution
- Tropical Monsoon Climate: Primarily found in the Indian subcontinent, Indo-China (Myanmar, Thailand, Laos, Cambodia, Vietnam), South China, and Northern Australia. It typically occurs between 10° and 25° North and South of the equator.
- Tropical Marine Climate: Experienced along the eastern coasts of tropical landmasses, such as Central America, the West Indies, Northeast Australia, Philippines, parts of East Africa, Madagascar, the Guinea Coast, and Eastern Brazil.
2. Climatic Characteristics
- Seasonal Reversal of Winds: The defining feature is the monsoon—a large-scale land and sea breeze caused by differential heating of land and water.
- Seasons of the Monsoon Climate:
- Cool, Dry Season (Oct to Feb): Dominated by out-blowing dry Northeast Monsoons in the northern hemisphere.
- Hot, Dry Season (March to mid-June): Characterized by high temperatures as the sun moves toward the Tropic of Cancer.
- Rainy Season (mid-June to Sept): Bringing heavy rainfall from the Southwest Monsoon.
- Marine Climate Stability: Unlike the monsoon climate, the Tropical Marine climate has more stable temperatures and steady rainfall throughout the year from trade winds, without a distinct dry season.
3. Natural Vegetation
- Deciduous Forests: Most trees in monsoon regions are deciduous, shedding their leaves during the marked dry period to withstand drought.
- Species: These forests are known for valuable durable hardwoods like teak, sal, sandalwood, rosewood, and shisham.
- Density: They are more open and less luxuriant than equatorial rainforests but still possess a layered structure (canopy, understory, and shrub layers).
4. Human and Economic Life
- Agriculture: The climate is highly favorable for agriculture due to the distinct wet season. Rice is the most important staple crop. Other major crops include maize, millet, yams, and sweet potatoes.
- Shifting Cultivation: This traditional “slash-and-burn” practice is common in these regions. It is known by various local names:
- Ladang in Malaysia.
- Taungya in Burma (Myanmar).
- Chena in Sri Lanka.
- Milpa in Africa and Central America.
- Habitation: The Tropical Marine climate is particularly favorable for human habitation due to its steady trade winds, though it is prone to severe tropical cyclones and hurricanes.
While the Equatorial climate is “constant,” the Monsoon climate is all about change. It is characterized by a distinct seasonal reversal of winds. This climate is most typically found in India, Pakistan, SE Asia, and Northern Australia.
1. The Monsoon Mechanism
The word Monsoon comes from the Arabic word Mausim, meaning season.
- Summer (On-shore): The huge landmass of Asia heats up, creating Low Pressure. Moist winds blow from the Sea to the Land, bringing heavy rain.
- Winter (Off-shore): The land cools down rapidly, creating High Pressure. Dry winds blow from the Land to the Sea, resulting in a dry season.
2. Three Distinct Seasons
- The Cool, Dry Season (Oct to Feb): Low temperatures, clear skies, and little rain (except for some coastal areas).
- The Hot, Dry Season (March to mid-June): Temperatures rise sharply. The land becomes scorched, and dust storms are common.
- The Hot, Wet Season (mid-June to Sept): The “Burst of the Monsoon.” Heavy rain falls, bringing relief from the heat.
3. Natural Vegetation
Unlike the dense Equatorial forests, Monsoon forests are Tropical Deciduous:
- Deciduous Nature: Trees shed their leaves in the dry season to prevent transpiration (loss of water).
- Hardwoods: The forests provide very valuable timber. The most famous is Teak (especially in Burma/Myanmar). Other trees include Sal, Acacia, and Bamboo.
- Structure: More open than the rainforest; easier to exploit commercially.
4. Economy & Development
- Agriculture: This is the most “intensive” farming region in the world.
- Crops:
- Rice: The most important staple crop (needs lots of water).
- Tea & Coffee: Grown on hill slopes (e.g., Assam, Sri Lanka, Java).
- Sugar Cane: Important in India and Java.
- Jute: Grown in the Ganges-Brahmaputra Delta.
10 Revision Questions with Mnemonics
Q1: What does the word “Monsoon” mean?
- A: It is derived from Mausim, meaning Season.
- Mnemonic: “Mausim = Movement” (of winds by season).
Q2: Why do Monsoon trees shed their leaves?
- A: To conserve water during the long dry season.
- Mnemonic: “Deciduous Drops leaves to avoid Dryness.”
Q3: Which is the most important commercial tree of the Monsoon forest?
- A: Teak.
- Mnemonic: “Teak is Top Timber.”
Q4: What causes the “Burst of the Monsoon”?
- A: The sudden arrival of moisture-laden winds from the Indian Ocean in June.
- Mnemonic: “Burst brings Buckets” of rain.
Q5: Which crop is known as the “Golden Fibre”?
- A: Jute.
- Mnemonic: “Jute is Jewelry” (Golden).
Q6: What is the “Tropical Marine” climate?
- A: Found on the eastern coasts of tropical lands (e.g., Central America, Philippines). It has rain year-round due to Trade Winds.
- Mnemonic: “Marine is Moist” (All year).
Q7: Which country is the world’s leading producer of Teak?
- A: Myanmar (Burma).
- Mnemonic: “Myanmar Makes Money from Teak.”
Q8: What is the main food crop in Monsoon Asia?
- A: Rice.
- Mnemonic: “Rice is the Real staple.”
Q9: Where is coffee primarily grown in this climate?
- A: On well-drained hill slopes (e.g., Brazil, Southern India).
- Mnemonic: “Coffee needs a Climb” (Slopes).
Q10: What is the “Shifting Cultivation” name in India?
- A: Jhum (or Bewar).
- Mnemonic: “Jhum is Jungle burning.”
Quick Summary Table: Monsoon vs. Equatorial
| Feature | Equatorial | Monsoon |
|---|---|---|
| Season | No Season (Constant) | 3 Seasons (Dry/Hot/Wet) |
| Leaves | Evergreen | Deciduous (Shed in dry) |
| Logging | Difficult (Mixed) | Easy (Pure Stands) |
| Mnemonic | “Equal all year” | “Monsoon Moves” |
