Physical Geography of Africa South of the Sahara Chapter 20 Physical Geography of Africa South of the Sahara

1. The Land Known for extraordinary physical geography Very diverse

Landforms MI: Africa south of Sahara is a region of plateaus, mountains and rift valley in east Massive region covers 9.5 million square miles

The Great Rift Valley Runs from Syria in SWA to Mozambique in SE Africa Rift valley – large depression in Earth’s surface, formed by tectonic plate movement Volcanic mountains at it’s edges, deep lakes Includes Mt. Kilimanjaro, one of largest mtns. in world Lake Tanganyika, one of deepest and longest freshwater lakes in world, lies on western branch of GRV Lake Malawi, more than 2300 ft deep

Mountains and Plateaus Series of plateaus, rise in elevation from coast inland Plateaus range in elevation from 500 ft to 8000 ft Edges lined by escarpments, steep jagged cliffs, and cataracts, or waterfalls Largest mountains include Kilimanjaro and Mt. Kenya

Water Systems MI: Landforms and physical processes have influenced the regions water systems (lakes, waterfalls, rivers) Lakes/rivers, located in basins, formed by tectonic activity Rivers start at high elevations, make their way to the sea

Land of Lakes Most lakes near Great Rift Valley, E Africa Lake Victoria, largest freshwater lake in Africa, second largest in world behind Lake Superior Lake Chad, W. Africa, shrinking due to irrigation, desertification, global warming Desertification – long periods of drought and land use destroy vegetation

Human Made Lake Lake Volta, W. Africa (Ghana), among largest HM lake in the world Created in 1960’s by damming Volta River Dam built for hydroelectric power in Ghana

River Basins Niger River, main river in W. Africa 2600 miles long Important for agriculture and transportation in region Forms Niger Delta upon entering Atlantic Ocean, 200 miles wide Delta – a triangular section of land formed by sand and silt carried downriver

River Basins Zambezi River, S. Central Africa 2200 miles long Headwater near the Zambia-Angola border, flows to Indian Ocean At border of Zambia and Zimbabwe, Zambezi falls 355 feet, forming Victoria Falls

River Basins Congo River, Central Africa About 2,900 miles long Reaches sea through an estuary, or passage where freshwater meets seawater

Natural Resources MI: Mineral resources and water are among the region’s most abundant natural resources Oil – Nigeria, Angola, Gabon, Congo and Cameroon 4 percent of world oil in Sub-Saharan Africa South Africa – half of worlds gold Uranium – South Africa, Botswana Water is abundant, but irregular and unpredictable, difficult to control for irrigation and hydroelectric power

2. Climate and Vegetation MI: Rain helps determine: climate vegetation growth

Tropical Climates Causes of variation in climate and vegetation: rainfall ocean currents prevailing winds elevation latitude

Tropical Wet Map of p. 516 TW Zone located near equator More than 60 inches of rain per year Produces variety of vegetation Rainforest levels: Low: ferns, moss, shrubs Mid: Trees, palms Canopy: leafy trees, max height of 150 ft Soil not fertile Heavy rains leach, or dissolve and carry away, nutrients from soil Crops grown: bananas, pineapples, cocoa, tea, coffee, timber, cotton

Tropical Dry Savanna, or grassland with scattered trees, covers half of Africa Alternating wet and dry seasons 35-45 inches annual rainfall Hot, dry air from Sahara, called harmattan, affects TDZone Cool, humid air from SW affect TDZone Combination at times forms tornadoes Animals: zebras, gazelles, hyenas, lions, giraffes and cheetahs

Dry Climates MI: Dry climates of Sub-Saharan Africa located in the north and south, away from the equator

Steppe Transition zone between tropical dry savanna and desert Northern steppe called the Sahel, from Senegal to Sudan 4-8 inches annual rainfall

Desertification Sahel, undergone desertification over past 50 years May be caused by climate change May be caused by human activities, animal grazing, logging, farming, etc.

Desert Namib Desert, Atlantic coast of Namibia Kalahari, eastern Namibia, Botswana and part of South Africa Daily temps in Kalahari vary widely, from 50 dg., night, to 120 dg., day

Midlatitude Coastal areas of South Africa, humid subtropical climates Highland East Africa, moderate climates, adequate rainfall for farming, some snow at high elevations