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1.2.Agriculture
Arable land amounts to only 6 percent of the continent’s area, while about 58 percent is in pasture used mainly for low-intensity grazing by cattle and sheep. The arable land, 80 percent of which is under cultivation, is confined to the nations humid and sub humid areas located in the southwestern of the continent and in a narrow fringe extending inland (no more than 250km) from the southeastern and eastern coastlands between Cairns in the north and Adelaide in the south. The lands used for pasture are concentrated in the generally drier parts of the continent, some 25 percent of all Australia being occupied by 16,000 ranches, or stations, averaging 75,000 acres in extend.
Australia is an important producer and exporter of agricultural products. It leads the world in wool production and is also an important supplier of wheat, other cereals, dairy produce, meat, sugar, and fruit. Australia’s sheep constitute about 12 percent of the world’s total sheep population and yield about 25 percent of the world’s wool as well as substantial quantities of mutton and lamb. Wheat, the chief crop, occupies nearly 70 percent of all cultivated land and is grown in almost all the states. Sugar is grown in the subtropical areas of coastal Queensland and New South Wales. The major fruit products include barriers, apples, bananas, and pin apples.
1.3. Water Resources
The driest of continents, Australia must carefully regulate its existing water resources. Even in some externally drained basins, water supply is at times deficient. Significant groundwater reserves occur beneath one quarter of Australia, most prominently in the Great Artesian Basin, but they are generally overexploited and such in unfit for human consumption.
Population
In 1994, Australia had an estimated population of 17,800,000, up from 10,100, 000in 1960. Immigration continues to play a major in population increase, more than 4 million new immigrants having settled in Australia since 1945. Despite a more diversified pattern of immigration in recent years, the population of Australia remains ethnically dominated by a majority that is of British descent (more than 90 percent from Great Britain and Ireland) or is recently arrived from the United Kingdom. Smaller ethnic groups of European origin include many of Greek, German, Italian, and Yugoslav descent. Aborigines and people of past Aboriginal descent constitute a small minority (only 1.5 percent of the total population); there are small but growing Chinese and other Asian minorities. Some of the descendants of Australia’s pre-European inhabitants, the Aborigines and Torres Strait Islanders, live on designated tribal lands, and others work o ranches or live in the deteriorated inner-city areas along the coast. In general, the Aborigines have a higher birthrate and a shorter life expectancy than other Australians do.
Climate
The climate of Australia varies with latitude. Because the continent lacks relief features and is favored with the moderating influence of the surrounding seas, few dramatic regional variations exist. The northern part of the continents is tropical and influenced by the trade winds. The southern parts lie in the belt of westerly winds and have a more temperate climate. The vast center of the continent is arid and extremely hot during the summer (December to March).
The tropical region, and especially the northern coast, experiences a hot, wet summer. The average January temperature in DARWIN is 28 degrees C, and the average annual rainfall is 1,240 mm, nearly 80 percent of which falls between December and March.
In winter, hurricanes tend to develop over the Coral and Arafura seas, some following the part of the East Australia Current as far south as Sydney. Hurricanes in 1974 devastated Darwin and flooded BRISBANE.
Southern Australia has mild, wet winters, resembling a Mediterranean climate. The southwest experiences hot, dry summers, dominated by subtropical high-pressure system. Average temperatures at Perth are 23 degrees C in January and 13 degrees C in July; the average annual rainfall is 900mm. A similar climate affects an area around ADELAIDE. Southern New South Wales, Victoria, and Tasmania have rainfall maximums in winter, but they receive the most dependable year- round precipitation of any region in Australia. The eastern coast of Queensland and New South Wales receive tropical summer rain. With increasing distance southward, however, temperatures decline and the seasonality of rainfall becomes less marked. On the southern Eastern Highlands is a sub humid belt, important for agriculture.
About half of Australia is arid. Dry seasons average eight months in length and a mean annual rainfall of 255mm or less. Summers are hot and winters are warm, and the daily temperature variation is great. The average temperature at ALICE SPRINGS is 26 degrees C in January and 12 degrees C in July. As with most of Australia, precipitation is undependable, and on rare occasions floods occur. For instance, 450,000 sq km of the Lake Eyre Basin (a region that normally receives only about 125 mm of rain annually) were completely flooded in 1974. The arid zone is encircles by a broad belt of semiarid climate. North of the tropic of Capricorn this belt records a wet summer season; south of the tropic of Capricorn, and especially in southwest Australia, the average summer is distinctly dry. Extreme high temperatures in the arid and semiarid regions exceed 38 degrees C.
Snow is rare except in the higher parts of the southern Eastern Highlands, principally the Snowy Mountains.
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