Australia: position, relief, climate and nature

Australia is the driest of the inhabited continents (Antarctica is the driest on the whole Earth). Most of the continent has a dry tropical climate, and in the centre and west rainfall is very low (100–500 mm). South-east trade winds from the ocean bring rain to the slopes of the Great Dividing Range on the east coast. There are four climate zones: subequatorial in the north (humid in summer — December to February — and dry in winter), a broad tropical zone, subtropical in the south, and temperate in Tasmania. Rivers are few: about 60 % of the area belongs to a closed inland basin; dry beds called creeks fill with water only after rare rain. The biggest river system is the Murray and its tributary the Darling (the Murray is about 2 500 km); lakes are salty and closed, the largest being Lake Eyre. Groundwater (the Great Artesian Basin) is very important for livestock. Natural zones: humid evergreen forests in the north-east, savannas in the north and east, deserts and thorny thickets called scrub in the centre, and hard-leaved forests in the south. Eucalyptus trees (some over 100 m tall) and acacias are typical. The animal world is unique: the marsupial kangaroo, koala, wombat and Tasmanian devil; the platypus and echidna, which lay eggs but nurse young with milk; the dingo, emu and malleefowl.