Form Three Geography Notes

All Form Three Geography Chapters

1. Chapter 1Major Climatic Regions of the WorldRead below · Free
2. Chapter 2Climate and Natural VegetationContinue in the app
3. Chapter 3SurveyContinue in the app
4. Chapter 4Simple ResearchContinue in the app

Learning Outcomes

By the end of this chapter, you should be able to:

• define climate, weather and climatic (natural) region;
• describe the location, characteristics, vegetation, economic activities and problems of the major tropical climates (Equatorial, Savannah, Hot Desert, Monsoon);
• describe the main features of Mediterranean, temperate and polar climates;
• explain the factors that influence climate;
• relate climate to human activities and environmental issues, including climate change.

Key Terms and Concepts

1. Meaning of Climate and Climatic Regions

Climate is the average of weather conditions over a long period (standard is about 30–35 years). When we talk about the climate of Dar es Salaam or London, we mean the typical temperature and rainfall pattern year after year.

Climatic (or natural) regions are large areas that share similar climate, vegetation, soils and often similar ways of life. Geographers divide the world into major climatic regions so that we can understand patterns of plant growth, animal life and human activities.

2. Tropical Climates

Tropical climates are found roughly between the Tropic of Cancer (23½° N) and the Tropic of Capricorn (23½° S). They are generally hot, but rainfall varies greatly.

2.1 Equatorial Climate

Location: Approximately 0°–5° North and South of the Equator (sometimes extending to 10°). Found in the Amazon Basin, Congo Basin, parts of Indonesia, Malaysia, and the East African coast near the Equator.

Characteristics: High temperature all year (daily mean about 26–27 °C; annual range only 2–3 °C); heavy rainfall usually more than 2000 mm with no real dry season; mainly convectional rain with thunder; high humidity; dense evergreen rainforest (selvas).

Economic activities: Plantation agriculture (cocoa, rubber, oil palm, bananas); subsistence and shifting cultivation; selective lumbering; fishing and some mining.

Environmental problems: Deforestation and loss of biodiversity; soil erosion and leaching after forest clearance; flooding; diseases such as malaria and bilharzia.

2.2 Tropical Grassland (Savannah / Sudan Type)

Location: Roughly 5°–20° North and South of the Equator. Found in much of East and West Africa (including large parts of Tanzania), Brazilian Plateau, Venezuela, northern Australia.

Characteristics: Distinct wet summer and dry winter; high summer temperatures; annual rainfall 500–1500 mm; tall grasses with scattered drought-resistant trees (acacia, baobab); famous for large herds of wild animals.

Economic activities: Livestock keeping; cultivation of maize, millet, sorghum, cotton, groundnuts; tourism (game parks and reserves – very important in Tanzania and Kenya); fishing.

2.3 Hot Desert Climate

Location: Western margins of continents between about 15° and 30° North and South. Found in the Sahara, Arabian Desert, Kalahari, Namib, Atacama, Australian deserts, Thar Desert.

Characteristics: Very high daytime temperatures (can exceed 40–45 °C); nights cool or cold; rainfall usually less than 250 mm; clear skies, strong sunshine; sparse vegetation (cacti, thorny bushes); sandy or rocky soils.

Economic activities: Nomadic pastoralism (camels, goats); irrigation agriculture around oases; mining (oil, gas, minerals); tourism in some areas.

2.4 Monsoon Climate

Location: Areas strongly influenced by seasonal reversal of winds, especially South and Southeast Asia, and parts of East Africa and northern Australia.

Characteristics: Wet season when winds blow from the sea; dry season when winds blow from the land. Rainfall can be very heavy but is seasonal. Vegetation ranges from dense monsoon forest to more open woodland.

Economic activities: Intensive agriculture (rice, tea, cotton, jute, sugarcane), fishing, dense human settlement in fertile river valleys.

3. Sub-Tropical Climates

3.1 Mediterranean Climate

Location: Western sides of continents between about 30° and 45° North and South. Found around the Mediterranean Sea, California, central Chile, south-western tip of South Africa, southern and south-western Australia.

Characteristics: Hot, dry summers and mild, wet winters; summer temperatures often 20–30 °C; winter usually mild (5–15 °C); annual rainfall 500–800 mm, mostly in winter; vegetation of evergreen shrubs, olive trees, cork oak, maquis/chaparral.

Economic activities: Growing of citrus fruits, grapes, olives, wheat and vegetables; wine production and tourism; some livestock keeping.

3.2 Warm Temperate Eastern Margin (China Type)

Location: Eastern sides of continents between roughly 23° and 35° N and S. Found in eastern China, southern Japan, south-eastern USA, parts of eastern Australia, southern Brazil.

Characteristics: Hot summers, cool winters, rainfall throughout the year (often higher in summer). Supports dense forests and intensive agriculture (rice, tea, cotton, maize).

4. Temperate Climates

Temperate climates lie mainly between about 40° and 60° latitude. Temperatures are moderate compared with the tropics and the polar regions.

4.1 Cool Temperate West Coast (British Type)

Location: Western coasts of continents between about 45° and 60° N and S. Found in north-west Europe (including Britain), north-west North America, southern Chile, South Island of New Zealand.

Characteristics: Mild summers and mild winters; rainfall throughout the year; strong oceanic influence. Natural vegetation is deciduous forest (much of it cleared for farming).

Economic activities: Mixed farming, dairy farming, manufacturing industries, fishing, trade.

4.2 Cool Temperate Continental (Siberian Type)

Location: Interiors of continents in the higher mid-latitudes (mainly Northern Hemisphere around 50°–65° N). Found in Siberia, northern Canada, interior Alaska.

Characteristics: Short warm summers and long, very cold winters; large annual temperature range; moderate rainfall, often with snow in winter. Vegetation is mainly coniferous forest (taiga).

Economic activities: Lumbering, mining, trapping, some farming in the south, fishing.

4.3 Warm Temperate Interior (Steppe Type)

Found in the interiors of continents (e.g. steppes of Eurasia, prairies of North America). Moderate rainfall, hot summers, cold winters; natural vegetation is grassland. Important for grain farming and livestock.

5. Polar Climates (Tundra and Ice Cap)

5.1 Tundra

Location: Beyond about 60°–65° North (and limited areas in the far south). Found in northern Canada, northern Siberia, northern Scandinavia, coastal Greenland.

Characteristics: Long, very cold winters; short, cool summers (warmest month usually below 10 °C); low precipitation, often as snow; permafrost in many areas; vegetation of mosses, lichens, sedges, dwarf shrubs – no tall trees.

Economic activities: Hunting, reindeer herding, fishing, limited mining and tourism; scientific research.

5.2 Polar Ice Cap

Location: High latitudes – most of Greenland and Antarctica.

Characteristics: Temperatures remain below freezing for most or all of the year; permanent ice and snow cover; very low precipitation; almost no vegetation. Human activity is limited to scientific research stations and some tourism.

6. Factors that Influence Climate

Climate of any place is controlled by several factors:

1. Latitude – distance from the Equator (most important control of temperature).
2. Altitude – temperature falls as height above sea level increases (about 6.5 °C per 1000 m).
3. Distance from the sea – coastal areas have milder climates (maritime); interiors have more extreme climates (continental).
4. Ocean currents – warm currents raise temperatures; cold currents lower them and can reduce rainfall.
5. Prevailing winds – winds from the sea bring moisture; winds from land are dry.
6. Relief / Mountains – windward slopes receive more rain; leeward sides are drier (rain shadow).
7. Aspect – in the Northern Hemisphere, south-facing slopes are warmer than north-facing ones.

Chapter Summary

• Climate is the average weather over a long period; climatic regions are large areas with similar climate and vegetation.
• Tropical climates (Equatorial, Savannah, Hot Desert, Monsoon) are hot; rainfall ranges from very high to almost none.
• Sub-tropical climates (especially Mediterranean) have hot dry summers and mild wet winters.
• Temperate climates have moderate temperatures and are important for farming and industry in many developed countries.
• Polar climates (Tundra and Ice Cap) are very cold and support limited human activity.
• Latitude, altitude, distance from the sea, ocean currents, winds and relief all influence climate.
• Human activities (farming, tourism, industry) and environmental problems are closely linked to each climatic region.
• Climate change is modifying these traditional patterns across the world.