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World Deserts. 6 th Grade History Ch. 1 Notes. What Is a Desert?. One word that describes all deserts is DRY Identified by how many inches of precipitation a location gets in an avg. year (moisture in the form of rain, snow, hail, or sleet)
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World Deserts 6th Grade History Ch. 1 Notes
What Is a Desert? • One word that describes all deserts is DRY • Identified by how many inches of precipitation a location gets in an avg. year (moisture in the form of rain, snow, hail, or sleet) • Most deserts get less than 10 in. of precipitation/year
What happens when it does rain? • Sudden thunderstorms cause flash flooding where the water washes quickly away before it can be absorbed into the ground • In lighter showers, most rain evaporates before it hits the ground because of dry air and heat
Desert Temperatures • There are both “hot” and “cold” deserts • Deserts near the equator are hotter • Deserts farther from the equator can be freezing cold • Both “hot” and “cold” deserts have dramatic changes between daytime and nighttime temperatures
Desert Landforms • Not all deserts have sand • They can have mountains, plateaus, canyons, or plains • Some are covered with gravel or bare bedrock
Life in the Desert • Key factor – the ability to adapt to the environment • Saguaro cactus • Kangaroo rat • Nocturnal animals
Shrinking/Growing Deserts • Turning deserts into farmland through irrigation • Changing weather patterns and wind • Desertification: The growth or expansion of deserts due to human activities