Class – 7
Subject – Geography
Chapter – 9
(Australia - Location, Political Division And Physical Features)
Australia was discovered in the beginning of the 17th century. Abel Janszoon Tasman, a Dutch navigator, sailed around the southern coast in 1642. The Islands of Tasmania and the Tasman Sea are named after him. After Tasman’s voyage, Caption James Cook sailed from England in 1788 and eventually landed at Botany Bay near Sydney. He hoisted the flag on Australia’s Eastern coast and claimed it for England.
Location and Extent
Australia lies entirely in the Southern and Eastern Hemisphere. It extends from 10 degree S to 44 degree S latitudes and from 112 degree east to 154 degree east longitudes. Tropic of Capricorn (23 ½ degree S) passes almost through its middle.
Boundaries
It lies between Indian Ocean (on the West) and Pacific Ocean (on the East). The Arafura Sea and the Timor Sea lie to its North and the Southern Ocean is to its South. The shape of Australia is like a quadrilateral. The area of Australia is 76,82,300 sq. km. It is the smallest continent in the world. It has 5.2 per cent of the world’s land area.
Political Divisions – States and Capitals
Australia is divided into six states – New South Wales, Victoria, South Australia, Queensland, Tasmania and Western Australia.
There are also two internal territories governed by the Central Government, i.e., Northern Territory and the Australian Capital Territory which includes Canberra, the capital of Australia. Both these territories are large but thinly populated.
Physical Features
Physically, Australia can be divided into four relief regions :-
1) The Eastern Highlands – The Eastern Highlands lie parallel to the eastern coast of Australia. They extend from Cape York in Queensland to the state of Victoria and continue along the southern side of the Shallow Bass Strait. They include- (i) The Great Dividing Range, (ii) The Great Barrier Reef. 2) The Central Lowlands – The Central Plains extend from Encounter Bay in the South to Gulf of Carpentaria in the North. These plains are divided into three parts- (i) The Murray Darling Basin, (ii) Lake Eyre Basin, (iii) The Carpentarian Lowlands. 3) The Western Plateau – It occupies the western half of the continent. It is composed of sandstone and limestone which lie in horizontal layers over the igneous rocks. The plateau slopes eastwards to the Central lowlands and South Wales to the Nullarbor Plain. 4) The Coastal Plains – In general the Western Plateau drops steeply to the sea, giving rise to an even coastline with few inlets, except in the northeast. Here, the sea is shallower and there are good harbors viz. Darwin Wyndham and Derby. Nullarbor plain is the coastal plain located towards the south of western plateau. It is a vast plain along the southern coast of Australia.
It is situated mainly in the state of Queensland and New South Wales. It is important for irrigation purpose and is a major source of groundwater supply. An artesian basin is a flat land. Here, the artesian wells are dug down where a basin of permeable rock such as chalk lies between two impermeable layers. The impermeable layer does not allow the water to go through and the water gets collected. If the water level is high the water will gush out like a fountain.
The Rift Valley of Australia
It is situated in South Australia. It is a long valley with steep walls and small plains within it. Lake Torrents, St. Vincent Gulf and Gulf of Spencer are parts of the Rift valley. The area is a popular tourist attraction.
Activity :-
Prepare a project report on Great Barrier Reef – location, formation, advantages and disadvantages. Use appropriate pictures, photos or diagrams.
Question & Answers :-
Ques-1) Explain the following terms – a)Inland Drainage, b) Paddock, c) Sheep Station and d)Coral Polyps.
Ans- a) Inland Drainage – A river system in which the rivers are not able to reach the sea or ocean and drain into some shallow salt lakes. b) Paddock – A field of grassland of any size for keeping sheep or cattle. c) Sheep Station – A sheep station is a large property in Australia or New Zealand whose main activity is the raising of sheep for their wool and meat. d) Coral Polyps – Tiny sea creatures living in sallow, warm and salty water of the sea.
Ques-2) What is meant by the term Australasia? What is the other name given to it? Ans- The term Australasia includes Australia, New Zealand and the neighbouring islands of the South Pacific Ocean. It is also called Oceania.
Ques-3) Name the political divisions of Australia.
Ans- Australia is divided into six states – New South Wales, Victoria, South Australia, Queensland, Tasmania and Western Australia and two union territories – Northern Territory and Australian Capital Territory.
Ques-4) How is coral reef formed?
Ans- Coral reef is formed by tiny sea creatures called Coral Polyps. They live in shallow warm salty water of the sea.
Ques-5) State the importance of the Murray-Darling Basin. From where does it get its water supply?
Ans- The Murray-Darling Basin is a rich agricultural area. It gets a ample water supply from the rivers. The Murray and Darling are snow-fed rivers originating from the Southern Alps.
Ques-6) Where is Great Artesian Basin situated? What is its importance?
Ans- The Great Artesian is situated mainly in the state of Queensland and New South Wales. It is important for irrigation purpose and is a major source of groundwater supply.
Ques-7) State any three favorable conditions for digging an artesian well.
Ans- i) The aquifer should be saucer shaped so that the water moves downward in it under the action of gravity. ii) There should be layer of porous rock between two layers of non-porous rocks. iii) There should be adequate rains to supply groundwater.