CH 6 – 1 Environmental Geography Sub-Saharan Africa
“Gondwanaland” The Pangaea theory is one that states that all present continents were once together and collectively known as a ‘meg-acontinent' called a Gondwanaland (Africa, South America, Antarctica, Australia, Madagascar & Saudi Arabia. http://www.exploratorium.edu/origins/antarctica/idea s/gondwana2.html http://www.exploratorium.edu/origins/antarctica/idea s/gondwana2.html This theory helps explains the numerous rifts, upland lakes, volcanoes & deep valleys in the region. *The bold-faced terms are: Gondwanaland; desertification, Sahel, transhumance, biofuels, Great Escarpment & Horn of Africa (7).
Major environmental issues: Deforestation – major cause is search for biofuels (wood & charcoal used for household energy needs); logging (ctr.Af.) & forest clearing for agricultural needs (worst deforestation is in Madagascar). Desertification – spread of desert like conditions which happens naturally is exacerbated by people living in delicate transitional areas (Ex: the Sahel – which is the ecological transition zone between the Sahara Desert & the wetter savannas further south that consists of several countries & millions of people) where they farm, herd & build communities. Transhumance (moving animals bet. wet & dry season pastures) is heavy in the Sahel; also overgrazing. Drought – The Sahel receives ltd. rain even during “wet season” which drastically effects farmers’ ability to produce enough food & very often leads to widespread famine.
Wildlife … POSITIVE: tourism; historically, people have co- existed well with wild life; most notable wildlife reserves are in East Africa (Kenya, Tanzania) – and Southern Africa, which are economically important. NEGATIVE: balancing the need to protect with the need to earn $$$ - so – poaching (illegal hunting and sale of wildlife) is a major issue.
Wildlife (continued)… CITES… Convention on International Trade in Endangered Species. Imposed a worldwide ban on legal ivory trade in 1989. Some African nations supported, some did not. Ban was lifted in late 1990’s but this continues to be a very controversial issue. (p. 266) Welcome to CITES Welcome to CITES http://www.wcs.org/ http://www.wcs.org/
Fault Zones in SSA… Sub-Saharan Africa is generally an elevated landmass, despite the lack of significant mt. ranges. This is the result of significant seismic activity many centuries ago which continues to impact the region’s geography today: there are numerous volcanoes, along with major fault zones like the Great Escarpment (Southern Af.), and the Rift Valley (Eastern Af.), as well as extremely deep lakes. Many geographers worry that Eastern Africa could eventually be torn away from the rest of the continent!
4 MAJOR RIVER SYSTEMS: NILE – world’ s longest river; links North and SSA. Site of earliest civilizations. Presently, many dam projects exist along the Nile, but war in Sudan hurts the even distribution of water. CONGO – largest watershed in terms of drainage. Runs through the Ituri Rain forest & is not totally navigable; Vital to getting products out of rain forests, war in the region has hurt the economic profitability of this waterway.
4 MAJOR RIVER SYSTEMS: NIGER: critical water source in otherwise arid nations. Historically a very important river for trade (Timbuktu) & currently for hydroelectricity. ZAMBEZI: much smaller, site of “Victoria Falls”; major supplier of commercial energy. Unfortunately dams in this area have not been much help in alleviating flooding. *Heavy irrigation, major dam construction, ever-growing demand from large populations and ltd. rainfall all contribute to ongoing drought in the region despite the presence of these River systems.
SOIL/CLIMATE/VEGETATION: SOILS: Soils here are relatively infertile and can’t support the intensive agriculture needed to feed the huge populations. (most fertile soils are in Rift Valley & around Lake Victoria). CLIMATE/VEGETATION ZONES: Tropical Forests – 2 nd largest rain forest (Ituri) is in Congo Basin. Very ecologically diverse. War & politically instability has actually protected this area from deforestation, but that is always a challenge in a forest region.
SOIL/CLIMATE/VEGETATION: Savannas – dominated by abundant trees/tall grasses in wet zones & scattered trees/short grasses in dry zones. Critical habitat for region’s wildlife (elephants, zebras, rhinos). Challenge = protecting the wildlife from hunting (legal & illegal); Deserts – Sahara – world’s largest (wraps around Horn of Africa); Namib (driest)- further south – rainfall is rare but temps are fairly mild; Kalahari – least dry of Africa’s deserts (desert = less than 10 in. rainfall/yr), this region supports some agriculture & grazing. Challenge = desertification.