Deserts! By: David Palacios Jimmy Kabbara Anahi Resendiz Transito Olmos

Geographic Location Deserts cover about one fifth of the Earth's surface and occur where rainfall is less than 50 cm/year. Although most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S., Mexico, and Australia, occur at low latitudes, another kind of desert, cold deserts.

Climate There is four types of climate deserts: 1.Hot and dry desert 2.Semiarid desert 3.Coastal desert 4.Cold desert

Hot and dry desert The seasons are generally warm throughout the year and very hot in the summer. The winters usually bring little rainfall.

Semiarid desert The summers are moderately long and dry, and like hot deserts, the winters normally bring low concentrations of rainfall. Summer temperatures usually average between 21-27° C.

Coastal desert The cool winters of coastal deserts are followed by moderately long, warm summers. The average summer temperature ranges from 13-24° C; winter temperatures are 5° C or below. The maximum annual temperature is about 35° C and the minimum is about -4° C. In Chile, the temperature ranges from -2 to 5° C in July and 21-25° C in January.

Cold desert They have short, moist, and moderately warm summers with fairly long, cold winters. The mean winter temperature is between -2 to 4° C and the mean summer temperature is between 21-26° C.

Animals Bobcat Meerkat Black Widow Spider Sidewinder Rattlesnake

Type: Mammal Diet: Carnivore Average lifespan in the wild: 10 to 12 years Size: Head and body, 26 to 41 in (66 to 104 cm); Tail, 4 to 7 in (10 to 18 cm) Weight: 11 to 30 lbs (5 to 14 kg Bobcat

Meerkat Approximate weight of a meerkatA is lbs. Approximate size of a meerkat: Average length is inches not including the tail.

Black Widow Spider The black widow spider can be found throughout parts of the United States. Weight: 1 gram. Length: Black Widow is considered the most venomous spider in North America.

Human Impacts on Deserts Many types of human activities hurt the desert. Off roading is one of these activities. Many people drive their off road vehicles in unrestricted areas all over the desert. Their vehicles leave tracks on the soil, which will scar the land for decades. Deserts are also being destroyed by development. Many people think that the deserts sunny weather is a perfect reason to build a home there, and businesses also bring more and more people into the desert. Irrigation, canals, pipes, farming, and urbanization have all changed the natural flow of water in the desert, and consequently, the desert climate itself. In Saudi Arabia, they use deserts to find oil, and in America, they use the deserts to test nuclear bombs. Mining, ranching operations, and grazing are all examples of the human impact on deserts.