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Australia, island continent located southeast of Asia and forming, with the nearby island of Tasmania, the Commonwealth of Australia, a self-governing member of the Commonwealth of Nations. The continent is bounded on the north by the Timor Sea, the Arafura Sea, and the Torres Strait; on the east by the Coral Sea and the Tasman Sea; on the south by the Bass Strait and the Indian Ocean; and on the west by the Indian Ocean. The commonwealth extends for about 4000 km (about 2500 mi) from east to west and for about 3700 km (about 2300 mi) from north to south. Its coastline measures some 25,760 km (about 16,010 mi). The area of the commonwealth is 7,682,300 sq km (2,966,200 sq mi), and the area of the continent alone is 7,614,500 sq km (2,939,974 sq mi), making Australia the smallest continent in the world, but the sixth largest country. x6n10nk
LAND AND RESOURCES Australia lacks mountains of great height; it is one of the world’s flattest landmasses. The average elevation is about 300 m (about 1000 ft). The interior, referred to as the outback, is predominantly a series of great plains, or low plateaus, which are generally higher in the northeast. Low-lying coastal plains, averaging about 65 km (about 40 mi) in width, fringe the continent. In the east, southeast, and southwest, these plains are the most densely populated areas of Australia.
In the east the coastal plains are separated from the vast interior plains by the Great Dividing Range, or Eastern Highlands. This mountainous region averages approximately 1200 m (approximately 4000 ft) in height and stretches along the eastern coast from Cape York in the north to Victoria in the southeast. Much of the region consists of high plateaus broken by gorges and canyons. Subdivisions of the range bear many local names, including, from north to south, the New England Plateau, Blue Mountains, and Australian Alps; in Victoria, where the range extends westward, it is known as the Grampians, or by its Aboriginal name, Gariwerd. The highest peak in the Australian Alps, and the highest in Australia, is Mount Kosciusko (2228 m/7310 ft), in New South Wales.
The western half of the continent is a great plateau, about 300 to 450 m (about 1000 to 1500 ft) above sea level. The Great Western Plateau includes the Great Sandy, Great Victoria, and Gibson deserts. Western Australia has, in its northern half, several isolated mountain ranges, including the King Leopold and Hamersley ranges. The interior is relatively flat except for several eroded mountain chains, such as the Stuart Range and the Musgrave Ranges in the northern part of South Australia and the Macdonnell Ranges in the southern part of the Northern Territory.
The central basin, or the Central-Eastern Lowlands, is an area of vast, rolling plains that extends west from the Great Dividing Range to the Great Western Plateau. In this region lies the richest pastoral and agricultural land in Australia. Uluru (Ayers Rock), in the center of Australia in Uluru National Park, is believed to be the largest monolith in the world. It is 9 km (6 mi) around its base and rises sharply to some 348 m (1142 ft) above the surrounding flat, arid land. Other mountain ranges of limited size in the central part of Australia are the Flinders Ranges and Mount Lofty Ranges in South Australia. The area along the south central coast is called the Nullarbor Plain. The Nullarbor is a vast, arid limestone plateau that is virtually uninhabited. It has an extensive system of caverns, tunnels, and sinkholes that contain valuable geological information about life in ancient Australia. Extinct volcanic craters are located in the southeastern part of South Australia and in Victoria.
The coastline of Australia is generally regular, with few bays or capes. The largest inlets are the Gulf of Carpentaria in the north and the Great Australian Bight in the south. The several fine harbors include those of Sydney, Hobart, Port Lincoln, and Albany.
The Great Barrier Reef is the largest known coral formation in the world. It extends some 2010 km (some 1250 mi) along the eastern coast of Queensland from Cape York in the north to Bundaberg in the south. The chain of reefs forms a natural breakwater for the passage of ships along the coast.
Rivers The Great Dividing Range separates rivers that flow east to the coast from those that flow across the great plains through the interior. The most important of the rivers that flow toward the eastern coast are the Burdekin, Fitzroy, and Hunter. The Murray-Darling-Murrumbidgee network, which flows inland from the Great Dividing Range, drains an area of more than 1 million sq km (more than 400,000 sq mi) in Queensland, New South Wales, Victoria, and South Australia. The Murray River and its main tributary, the Darling, total about 5300 km (about 3300 mi) in length. The Murray River itself forms most of the border between New South Wales and Victoria. Considerable lengths of the Murray, Darling, and Murrumbidgee rivers are navigable during the wet seasons.
The central plains region, also known as the Channel Country, is interlaced by a network of rivers. During the rainy season these rivers flood the low-lying countryside, but in dry months they become merely a series of water holes. The Victoria, Daly, and Roper rivers drain a section of Northern Territory. In Queensland the main rivers flowing north to the Gulf of Carpentaria are the Mitchell, Flinders, Gilbert, and Leichhardt.
Western Australia has few major rivers. The most important are the Fitzroy, Ashburton, Gascoyne, Murchison, and Swan rivers.
Because of Australia’s scarce water resources, dams have been constructed on some rivers to supply cities with water and to support irrigation farming. The Snowy Mountains Scheme (1949-1972) and the Ord River Scheme (1960-1972) are the two largest water-conservation projects. The Snowy Mountains Scheme, in the southeastern highlands in New South Wales, is an enormous, multipurpose engineering project that was financed by the federal and state governments to supply water for irrigation, domestic and livestock use, and for the generation of hydroelectricity. The Ord River Scheme is an irrigation project in the remote Kimberley region of Western Australia. During its construction the scheme attracted criticism from economists, environmentalists, and agriculture scientists, and today questions remain about its viability.
Lakes and Underground Water Most of the major natural lakes of Australia contain salt water. The great network of salt lakes in South Australia—Lake Eyre, Lake Torrens, Lake Frome, and Lake Gairdner—is the remains of a vast inland sea that once extended south from the Gulf of Carpentaria. During the dry season many of the salt lakes become salt-encrusted swamp beds or clay pans. Lake Argyle, created by the construction of the Ord River Scheme, is Australia’s largest artificially created freshwater lake.
Great areas of the interior, which otherwise would be useless for agriculture, contain water reserves beneath the surface of the land. These artesian water reserves, usually found at a great depth, are tapped by drilling to provide water essential for livestock. Artesian water reserves underlie about 2.5 million sq km (about 1 million sq mi) of Australia. The Great Artesian Basin, extending from the Gulf of Carpentaria into the northern part of New South Wales, includes more than 1.7 million sq km (700,000 sq mi). Other artesian basins are in the northwest, southeast, and along the Great Australian Bight.
Plants The continent of Australia has a distinctive flora that includes many species not found elsewhere. Of the 22,000 species of plants in Australia, more than 90 percent occur naturally there. Some 840 species are threatened with extinction, and 83 have become extinct since the beginning of European settlement. Approximately 2000 plant species are introduced, or nonnative, species. Most have been associated with the development of agriculture and grazing, or with the establishment of large plantations of pines for commercial softwood. The spread of weeds and other aggressive introduced plants into areas of original vegetation is a serious environmental challenge.
Australia’s vegetation is predominantly evergreen, ranging from the dense bushland and eucalyptus forests of the coast, to mulga and mallee scrub and saltbush of the inland plains. The tropical northeastern belt, with its heavy rainfall and high temperatures, is heavily forested. Palms, ferns, and vines grow prolifically among the oaks, ash, cedar, brush box, and beeches. Mangroves line the mud flats and inlets of the low-lying northern coastline. The crimson waratah, golden-red banksias, and scarlet firewheel tree add color to northern forests.
Along the eastern coast and into Tasmania are forests of pine, which ranks second to the eucalyptus in terms of economic importance. The Huon and King William pines are particularly valuable for their timber, but the Huon pine is now considered rare and is usually protected. In the forest regions of the warm, well-watered southeastern and southwestern sectors, eucalyptus predominates; more than 500 species are found, some reaching a height of 90 m (300 ft). The mountain ash, blue gums, and woolly butts of the southeast mingle with undergrowth of wattles and tree ferns.
The jarrah and karri species of eucalyptus, which yield timber valued for hardness and durability, and several species of grass tree are unique to Western Australia. The wild flowers of the region are varied and spectacular. In the less dense regions of the interior slopes grow red and green kangaroo paws, scented Boronia, waxflowers, bottle brushes, and smaller eucalypti, such as the stringbark, red gum, and ironbark. More than 500 species of acacia are indigenous to Australia. The scented flower of one acacia, the golden wattle, is the national flower of Australia and appears on the official coat of arms. In the interior region, where rainfall is low and erratic, characteristic plants are saltbush and spinifex grass, which provide fodder for sheep, and mallee and mulga shrubs.
The most valuable native grasses for fodder, including flinders grass, are found in Queensland and northern New South Wales. During occasional seasonal floodings, rapid and luxuriant growth of native grasses and desert wildflowers occurs, and water lilies dot the streams and lagoons.
Animals Unique and primitive forms of animal life exist in Australia. Seven families of mammals and four families of birds are classified as native to the country. About 70 percent of the birds, 88 percent of the reptiles, and 94 percent of the frogs are unique to Australia. Seven of the more than 750 known species of birds have become extinct since the beginning of European settlement, and another 45 are endangered or vulnerable. Of mammals, 19 are extinct and 58 are threatened. Environmentalists have argued for more rigorous conservation policies to protect Australia’s unique animal life.
One striking aspect of mammal life in Australia is the absence of representatives of most of the orders found on other continents. However, the primitive, egg-laying mammals known as monotremes are found most abundantly in Australia. One of them, the platypus, a zoological curiosity, is an aquatic, furred mammal with a bill like that of a duck and with poisonous spurs. It lives in the streams of southeastern Australia. Another monotreme of Australia is the spiny anteater, or echidna.
Most native mammals are marsupials, the young of which are nourished in an external marsupium, or abdominal pouch. The best-known marsupials of Australia are the kangaroos, which include about 50 species. The kangaroo is vegetarian and can be tamed. The large red or gray kangaroo may stand as high as 2 m (7 ft) and can leap up to 9 m (30 ft). The wallaby and kangaroo rat are smaller members of the kangaroo family. The phalangers are herbivorous marsupials that live in trees; they include the possum and the koala, a popular fur-bearing animal that is protected throughout Australia. Other well-known marsupials are the burrowing wombat, bandicoot, and pouched mouse. The carnivorous Tasmanian devil, principally a scavenger, is found only on the island of Tasmania.
Rodents, bats, and the dingo, or warrigal, belong to a different order of mammals. The dingo is a doglike night hunter that also preys on sheep; it does not bark, but howls.
When Europeans settled in Australia, they brought in many species of animals. The wild descendants of these introduced animals pose serious environmental threats. For example, the European rabbit was brought in mainly for sport in the mid-19th century. These rabbits quickly reached plague proportions in Australia’s receptive environment with no natural predators, and their total population has reached as many as 500 million. The damage they cause includes soil erosion, the destruction of habitat for native species, and large commercial production losses. Rabbits, as well as foxes and cats, have been targeted for massive national efforts in biological control and regional eradication programs. Other destructive animals include pigs, goats, cattle, horses, and camels. In the monsoonal areas of tropical Australia, the Asian water buffalo has increased its population over a vast territory; it is responsible for erosion and the disruption of delicate swamp habitats.
The waters surrounding Australia support a wide variety of fish and aquatic mammals. Several species of whales are found in southern waters, and seals inhabit parts of the southern coast, the islands in Bass Strait, and Tasmania. The northern waters supply dugong, trepang, trochus, and pearl shell. Edible fish and shellfish are abundant, and the oyster, abalone, and crayfish of the warmer southern waters have been exploited commercially. Australian waters contain some 70 species of shark, several of which are dangerous to humans. The Queensland lungfish, sometimes called a living fossil, is a primitive fish that breathes with a single lung instead of gills.
Most insect types are represented in Australia, including flies, beetles, butterflies, bees, and ants. The giant termites of northern Australia build huge, hill-like nests up to 6 m (up to 20 ft) in height. Australia has earthworms in abundance, including the giant earthworms of Victoria, which range from 0.9 to 3.7 m (3 to 12 ft) in length, the longest in the world.
Australia is the home of 751 known species of birds, ranging from primitive types, such as the giant, flightless emu and cassowary, to highly developed species. The fan-tailed lyrebird has great powers of mimicry. The male bowerbirds build intricate and decorative playgrounds to attract females. The kookaburra, or laughing jackass, is noted for its raucous laughter. Many varieties of cockatoos and parrots are found; the budgerigar is a favorite of bird fanciers. The white cockatoo, a clever mimic, is more common than the black cockatoo. Black swans, spoonbills, herons, and ducks frequent inland waters. Smaller birds include wrens, finches, titmice, larks, and swallows. Gulls, terns, gannets, muttonbirds, albatrosses, and penguins are the most common seabirds. The muttonbird, found mainly on the islands of Bass Strait, is valued for its flesh.
Agriculture Despite the great expansion in mining and manufacturing after 1940, the prosperity of much of the country continues to be dependent on livestock raising and crop farming. The pastoral industry was established in the early days of settlement, when the first Spanish merino sheep were introduced from South Africa. The industry was a significant factor in Australian economic and historical development. Australia currently is the major world producer and exporter of wool, particularly fine merino, although income from wool exports is now less than one-tenth of the total export income of the country. In 1997 the annual production of wool was 688,900 metric tons. About half the country’s wool is produced in New South Wales and Western Australia.
In the past the country’s great rabbit population hampered sheep raising by foraging on grazing land. Although rabbits accompanied the First Fleet that arrived in Australia in 1788, their first significant arrival occurred in 1859 at the behest of a landowner, Thomas Austin. The shipment of two dozen wild rabbits was released on his property near Geelong, Victoria. Within three years the rabbits had assumed the proportions of a potential pest. Subsequently, the rabbit population was estimated to have reached some 500 million, or about 50 times the human population of Australia. The virus disease myxomatosis, which attacks rabbits, was introduced in 1936 and proved an effective control for about 20 years. The rabbit population increased markedly thereafter and is again an economic and environmental threat.
Queensland is the leading cattle-producing state, containing more than two-fifths of the estimated 26.3 million head of cattle in Australia in 1997. The country produces both beef and dairy cattle. Dairying is concentrated in Victoria and Tasmania. Irrigation is heavily relied on in much of the fruit-growing and dairying regions. In some areas the rising incidence of soil salinization threatens production. Experiments with biotechnologies may reduce the impact of salinization and the use of expensive water resources.
Although only 6 percent of the total area of Australia is under crop or fodder production, this acreage is of great economic importance. Wheat crops occupy about 45 percent of cultivated acreage, and other grains occupy about 25 percent. The bulk of the wheat crop is grown in the southeastern and southwestern regions of the country. Production in 1997 was 16.2 million metric tons. Oats, barley, rye, hay, and fodder crops also are important. Rice and cotton are grown in the Murrumbidgee Irrigation Area (in New South Wales) and in the Northern Territory. Sugarcane production is confined to the fertile coastal fringe of Queensland and the Richmond River district of northern New South Wales. Some 40.8 million metric tons of sugarcane were produced in 1997. Many types of fruit are grown, including grapes, oranges, apples, bananas, pears, pineapples, peaches, and nectarines. The major wine-producing areas are in the Barossa Valley of South Australia, the Hunter Valley, New South Wales, and parts of northeastern, southern, and western Victoria. Special varieties of grapes are grown, especially in the Murray Valley, for the production of raisins.
Australian waters contain a great variety of marine life, but the annual catch is relatively small—219,500 metric tons in 1995. More than 85 percent of the yearly value of exported fishery products is made up of various shellfish, principally scallops, shrimp, spring and green rock lobsters, oysters, and abalone. Marine fishes marketed include orange roughy, sharks and rays, skipjack tuna, mullet, southern bluefin tuna, and royal escolar. Pearls and trochus shells have been harvested off the northern coast since the 1800s. Darwin, Broome, and Thursday Island are the main pearling centers, but cultured pearls are now more significant. The cultured pearl industry is dominated by Japanese-Australian ventures. Australia was a principal whaling nation until the late 1970s, when it agreed to halt most whaling activities in cooperation with an international effort to maintain the whale population.
Mining The mining industry, long an important factor in the social and economic growth of Australia, holds great promise for the future development of the country. The gold discoveries of the 1850s were responsible for the first wave of immigration and for settlement of inland areas. Today, Australia is self-sufficient in most minerals of economic significance, and in a few cases is among the world’s leading producers. Annual Australian production of coal, oil, natural gas, and metallic minerals was valued at about $12.4 billion in the early 1990s. Metallic minerals accounted for more than two-fifths percent of the total, with gold and iron ore the most significant components. Western Australia had the largest share of total mineral production, especially of metallic minerals.
Australia accounted for some 13 percent of the world’s gold production in 1997. About three-fourths of the nation’s output (289,000 kg/637,000 pounds in 1996) is mined in Western Australia, notably near Kalgoorlie. Most of the gold is exported to Singapore, Japan, Switzerland, and Hong Kong. Australia is also the world’s largest producer of diamonds, producing about two-fifths of the global total. Production of gem-quality diamonds was 18,897,000 carets in 1996. Much of it came from the giant Argyle Diamond Mine in the Kimberley region of Western Australia. About 95 percent of Australia’s iron-ore production also takes place in Western Australia, in the Pilbara region. Iron-ore reserves also exist at Iron Knob in South Australia; on Cockatoo Island in Yampi Sound off Western Australia; in northwestern Tasmania; and in Gippsland, Victoria. Almost all of the iron ore is exported; Australia is now Japan’s major supplier of iron ore. Other markets include China, Germany, South Korea, and Taiwan.
Australia is the world’s largest bauxite and alumina producer and the fourth largest aluminum producer. The major bauxite mines are located to the south of Perth in Western Australia; and in the Northern Territory on the Gove Peninsula. Important uranium mines are located in the Northern Territory (Ranger Mine) and at Olympic Dam in South Australia. All uranium is exported.
Hard, or black coal, mining is heavily concentrated in New South Wales and Queensland. The lignite, or brown coal, industry is located in Victoria, where it is used to produce electricity. Other major minerals in Australia include nickel, mined near Kalgoorlie; copper, mined at Mount Lyell in Tasmania, Mount Isa in Queensland, and Tennant Creek in the Northern Territory; zinc, mined at Broken Hill in New South Wales; and manganese, mined at Groote Eylandt, Northern Territory. Titanium and zircon are recovered from the beach sands of southern Queensland, New South Wales, and Western Australia. Queensland, New South Wales, and Tasmania are the main tin-producing states, and tungsten concentrates are mined on King Island in the Bass Strait. Petroleum has been discovered in Western Australia, in southern Queensland, and offshore in Bass Strait. Total production in 1996 was 208 million barrels. Natural gas is also extracted, with annual production of 29.9 billion cu m (1055 billion cu ft).
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