Hot deserts Most hot deserts are located between the Tropic of Cancer and the Tropic of Capricorn (see FIGURE2 ). Summers are hot and winters warm. As cloud cover is rare, the ground heats during the day and escapes at night, making temperature extremes common. Temperatures can range between 45 ° Cand –15 ° C in a 24-hour period. Cold deserts Cold deserts lie on high ground north of the Tropic of Cancer and south of the Tropic of Capricorn (see FIGURE2 ). They include the polar deserts. Any precipitation falls as snow. Winters are very cold and often windy; summers are dry and cool to mild. 13.8.2 Desert dwellers Many people in desert regions live a nomadic lifestyle and move with the seasons, obtaining their needs from the land or trade. Some herd animals. The harsh climate and lack of water make it difficult for large cities to develop, other than in coastal areas where rivers provide a reliable water supply. 13.8.3 Comparing deserts in China and Australia Deserts exist in different parts of the world ( FIGURE2 ): the subtropics, interior of continents, leeward sides of mountain ranges, along the coast and in polar regions. The only common factor is low rainfall.
• The Gobi Desert is both a rain-shadow ( FIGURE 3 ) and inland desert. • Australia’s deserts are rain-shadow and coastal ( FIGURE3 ) deserts.
SkillBuilder discussion Geographical inquiry 1. Study FIGURE3 .What is the direction of the prevailing winds in each image? 2. What happens to the winds once they pass over the land? 3. Write two or three sentences to explain how each type of desert forms.
FIGURE 3 (a) The formation of rain-shadow deserts and (b) the formation of coastal deserts
Rising moist air produces rain.
Dry air continues over mountains.
Winds become dry by the time they reach inland areas.
Trade winds are forced to rise.
Sea
Inland
Mountains
Coast
Desert
Thousands of kilometres
Fog or rain occurs at sea, or on the coast.
Dry air blows inland.
Cooler air
Cold ocean current
322 Jacaranda Humanities Alive 8 Victorian Curriculum Third Edition
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