Biology Reference
In-Depth Information
mixture of grass plains and woodland savanna dominated by thorn bushes, thorny acacia trees,
and by deciduous mopane trees in the north. The rivers are seasonal in water flow and in the
dry winter season their long sandbanks, speckled by hippos and crocodiles, prevent accurate
navigation.
Early Europeans, Mining, Water, Energy Demands and Climate Change:
Southern Africa's interior was only first explored in the early and mid-1800s by Dutch
farmers, the Boers (The Great Trek 1835), and missionaries such as Moffat and Livingstone.
Natural scientists such as Barrow (1800), Burchell (1811) and Smith (1835), and hunter-
explorers including William Cornwallis Harris, Roualeyn Gordon-Cumming, and W.C.
Baldwin and Robert Briggs Struthers are also those who traversed the area. Gordon -
Cumming and Baldwin were known to travel with entourages of 100 to 200 Africans, 100 or
more oxen, 25 or so horses, and numerous dogs because disease (particularly Nagana
inoculated by tsetse flies), lack of water, and lions took a large toll on travel. Medical
missionary David Livingstone traveled north from Cape Town in 1854 to what is presently
Botswana to found a mission station under the guidance of his father-in-law Robert Moffat
before moving further north through the swamps between the Zambezi and Congo River
watersheds. He then traveled westward through the Quango Valley down to Cassanga
(Kassanga) and onto the Portuguese port of Luanda in Angola on the Atlantic. He later returned
to the Zambezi and in November 1855 travelled eastward to the Indian Ocean. Based on Adam
Smith's topic on the Wealth of Nations which suggested that societies near waterways have
greater success, Livingstone believed the Zambezi River was navigable to the center of Africa
along present Zimbabwe's northwestern border. However, during a period of malarial fever
and taking a short cut, he missed the rapids in eastern Mozambique at Kebrabassa that
prevented navigation. The dam wall of Cahora Bassa is now built there, creating a huge man-
made lake that also generates some 2000 megawatts of hydroelectric power. One megawatt
typically powers about 1000 homes in the United States; the Hoover Dam, for example,
produces 1345 MW and the Grand Coulee Dam 6809 MW and is the USA's biggest
hydroelectric power plant. The Kariba dam also had a 2000-megawatt capacity but can now
no longer even meet the 1,200-megawatt needs of Zimbabwe because of failed turbines. With
the building of dams like Cahora Bassa and Kariba to try and retain the summer water runoff,
and also to produce hydroelectric power, the seasonal flow of the rivers is more controlled but
water in the interior is becoming an even scarcer commodity as diamond mines need more
water in desert areas and gold mines go deeper underground to more than 2.4 miles and need
more water and even ice to cool the rock slopes.
The Mponeng mine is 13,000 feet deep and the surface rock measures 134 degrees
Fahrenheit with plans to mine to 14,500 feet; this depth is equal to ten Empire State buildings.
Currently, there are some 20,000 miles of underground railway lines to service the mines,
nearly enough to circle the globe. Three million bathtubs full of water have to be pumped out
every day and the gold mines consume a huge amount of electricity, roughly 23 megawatts per
hour enough for a city of 3 million people although New York City needs 10 megawatts of
power. A possible future problem may be that as these mines get shut down, the miners will no
Search WWH ::
Custom Search