Chapter 20 Review

spot in a desert where water is found

• marginal land

• oasis

• wadi

long period in which little or no rain falls

• deforestation

• drought

• desertification

steady winds in tropical latitudes that blow toward the equator from the north and south

• windbreaks

• trade winds

• prevailing winds

land that is not well suited for growing crops

• oasis

• marginal land

• reg

Groups of herders who move with their animals from place to place in search of pasture and water

• hunter-gatherers

• pastoral nomads

• Craftsmen-handymen-traders

the process by which land becomes more and more dry until it turns into desert.

• shifting agriculture

• desertification

• deforestation

tall sand dune in the Sahara

• reg

• erg

• hammada

gravel-covered plain in the Sahara

• erg

• reg

• hammada

high, rock-covered flatland in the Sahara

• erg

• hammada

• reg

the usually dry bed of a river or stream in an arid area.

• reg

• wadi

• hammada