Barbara Yip. age 12. of Toronto. Canada.

Why is central Australia a desert?

Australia lies below the equator. most of it within tropical latitudes. This means that its prevailing winds are the south‑east trades. They blow over the south Pacific and strike Australia's eastern shoreline. Here they meet resistance. A long chain of mountains rims the coast from north to south.

This chain of hills is from 100 to 250 miles wide. The tallest crest is no higher than 7380 feet. But the highland area forces the trade winds to unload their moisture. The hills are dug with gorges from this rainfall. The winds that continue on their way eastward are dry winds.

They blow on right over the huge island continent without bumping into any more mountains. The central area is a vast. flat plain. There are no ‑pore highlands to force up the winds and wring out their rain. The central area is barren desert. Over many years. the average rainfall of central Australia may be ten inches ‑ which is very little. But long droughts are common. Sometimes no rain falls at all for many seasons.