Australia Chapter Notes | Geography Class 7 ICSE PDF Download

Introduction

Location

• Located southeast of mainland Asia and southwest of North America.
• Known as the "Land Down Under" as it lies entirely south of the Equator.
• Extends from 10°S to 44°S latitudes and 112°E to 154°E longitudes.
• Tropic of Capricorn runs through the center of the continent.

Boundaries of Australia

• Completely surrounded by water.
• Pacific Ocean lies to the east and northeast.
• Indian Ocean lies to the west and northwest.
• Southern Ocean surrounds Australia and New Zealand in the south.
• Timor Sea, Gulf of Carpentaria, and Arafura Sea are to the north.
• Shares marine boundaries with Indonesia, East Timor, Papua New Guinea, New Zealand, New Caledonia, Solomon Islands, and Vanuatu.

States and Capitals

• Australia is a federation with six states and two mainland territories.
• States:  New South Wales, Queensland, South Australia, Tasmania, Victoria, Western Australia.
• Mainland territories: Australian Capital Territory, Northern Territory.
• National capital: Canberra.

Major Physical Features of Australia

• Topography is mostly flat with no high mountain ranges.
• High evaporation rates in arid regions due to flat terrain.
• About 50% of rivers drain inland, often into salt lakes; only 30% reach the sea.
• Divided into three main regions: Eastern Highlands, Central Lowlands, Western Plateau.

Eastern Highlands

• Run along the eastern and southeastern sides, extending into Tasmania.
• Feature steep cliffs on the eastern side and coastal strips up to 96 km wide.
• Includes Blue Mountains and New England Range in New South Wales, and Australian Alps in Victoria.

The Great Dividing Range

• Also known as Eastern Highlands, it acts as the main watershed.
• Separates rivers flowing east to the Pacific Ocean from those flowing west to the Central Lowlands.

Blue Mountains

• Located in New South Wales, bounded by Nepean, Hawkesbury, Coxs, Wolgan, and Colo rivers.
• Situated in the central Sydney Basin.
• Forms a watershed between Coxs River to the south and Grose and Wolgan rivers to the north.

The Australian Alps

• Found in Victoria, characterized by plateaus, ridges, steep slopes, escarpments, and gorges.
• Not as high as European Alps but snow-covered for 5–6 months annually.
• Mount Kosciuszko, at 2,228 meters, is the highest peak in Australia.

Coastal Plain

• Runs along the eastern coast, varying from tropical lush areas to dry sandy plains.
• Warm, moist climate and fertile farmland make it the most populated region.

Central Lowlands

• Flat, low-lying area from Eastern Highlands to Western Plateau, and Gulf of Carpentaria to Encounter Bay.
• Divided into Carpentaria Lowlands, Lake Eyre Basin, and Murray-Darling Basin based on drainage.

Carpentaria Lowlands

• Spread around the Gulf of Carpentaria in the northern region.
• Contains the Great Artesian Basin, the world’s largest artesian basin, supplying groundwater for irrigation.
• Groundwater gushes out naturally due to high pressure in sandstone covered by marine sedimentary rock.

Lake Eyre Basin

• Located south of Carpentaria Lowlands, covering one-sixth of Australia’s area.
• Lake Eyre, 15 meters below sea level, is the continent’s lowest point.
• Forms the world’s largest inland drainage basin as small rivers flow into it instead of the sea.

Murray-Darling Basin

• Located in southeast Australia, ideal for farming due to Murray and Darling Rivers.
• Has less water-carrying capacity but supports agriculture in the region.

Western Plateau

• Flat area about 600 feet above sea level, covering over half of Australia.
• Includes low mountain ranges in northern Western Australia and isolated uplands in the Northern Territory.
• Known as the Outback, featuring large beef cattle stations and vast deserts.
• Deserts include Gibson, Tanami, Canning, Great Sandy, and Great Victoria.
• Dry due to cold water currents off Western Australia’s coast.

Ayers Rock

• Also called Uluru, a famous sandstone rock and World Heritage Site.
• 300 million years old, changes color from reddish-brown at dawn to yellow and violet.

Rivers

• Murray
• Murrumbidgee
• Darling, Lachlan
• Cooper Creek.

Murray River

• Longest river, 2,508 km, starts in the Australian Alps and flows to the Southern Ocean near Adelaide.
• Located in New South Wales and South Australia, forms part of the New South Wales-Victoria border.

Darling River

• Second-longest, 1,472 km, starts in the Great Dividing Range and joins the Murray River.
• Forms the Murray-Darling River Basin, vital for farming and irrigation.

Murrumbidgee River

• 1,600 km long, flows through New South Wales and Australian Capital Territory.
• Originates in the Snowy Mountains at over 1,500 meters and joins the Murray River.

Lachlan River

• 1,440 km long, flows through New South Wales, starting in the Great Dividing Range.
• Ends in the Great Cumbung Swamp near Oxley, New South Wales.

Cooper Creek

• Fifth-longest river in Australia, stretching about 1,300 kilometers.
• Flows through Queensland and South Australia.
• Ends at Lake Eyre in South Australia.

Deserts

Great Victoria Desert

• Largest desert, located in Western and South Australia, covering 348,750 square km.
• Features grasslands, sand-hills, salt lakes, and pebbled surfaces.
• Receives 200–250 mm rainfall annually, supports Acacia, Eucalyptus, and Spinifex grass.

Great Sandy Desert

• Second-largest desert, in northern Western Australia, covering 284,993 square km.
• Surrounded by Gibson and Tanami Deserts, with sand dunes, low hills, and salt lakes.
• Receives 250 mm rainfall annually, up to 300 mm in northern monsoon-affected areas.
• Contains native plants like bloodwood, acacias, and grevillea, and the Wolfe Creek meteorite crater.

Coastal Plains

• Extends from Queensland to Victoria, bordered by the Tasmanian Sea, South Pacific Ocean, and Great Dividing Range.
• Receives heavy rainfall in summer, making it fertile and suitable for agriculture.

Western Coastal Plain
Adjacent to the Western Plateau, receives less rainfall and has sparse vegetation.
Nullarbor Plain

• Along the southern coast, bordered by the Great Australian Bight.
• Known for its vast treeless landscape, named from Latin "null" (no) and "arbor" (tree).

Great Barrier Reef

• World’s largest coral reef system, over 2,000 km long, off Australia’s northeastern coast.
• Formed by skeletons of dead polyps, creating colorful underwater ecosystems.
• A national park attracting millions of tourists annually.
• Faces threats from oil drilling, but the government is protecting it.

Fun Fact

• Trans-Australian Railway is 1,171 km long, connecting western and eastern Australia.
• Includes the world’s longest straight railway track, 478 km, between Ooldea and Loongana.
• Nullarbor Plain’s name comes from Latin, meaning "no trees."

Points To Remember

• Australia includes mainland, Tasmania, and small islands in the Indian and Pacific Oceans.
• It is the sixth largest country and smallest continent.
• A federation of six states and two mainland territories.
• Divided into Eastern Highlands, Central Lowlands, and Western Plateau.
• Major rivers: Murray, Murrumbidgee, Darling, Lachlan, Cooper Creek.
• Lake Eyre is the largest lake, covering one-sixth of Australia, and the lowest point.
• Largest deserts: Great Victoria and Great Sandy Deserts.
• Great Barrier Reef is the world’s largest coral reef system.