A desert is an area or geographical region which receives very little rainfall. Effect of such a low precipitation of rain is that there is not enough water to support the growth of most plants. Deserts make up about 20 percent of the Earth’s land surface and can be located in either very hot or very cold regions.
The Antarctic desert is the world’s largest desert. The Antarctic desert is located in Antarctica, which is the fifth largest continent in the world. This desert is so-defined because it has an annual precipitation of less than 8 inches along the coast and less than 2 inches in the interior. For an area to be considered a desert, it must have an annual precipitation less than 10 inches annually. There is very little evaporation from Antarctica, unlike the other deserts, so any snow that does fall never goes away; instead, it piles up to form the enormously thick ice sheets in the Antarctic region. Precipitation in the Antarctic region does not fall in the form of rain; it falls in the form of snow.
While the Antarctic desert is the largest desert generally, the Sahara desert is the largest hot desert in the world. This desert is located in Africa and constitutes about 10 percent of the African content. Although the precipitation in the Sahara is low, various species of plants and animals have adapted to live in this region. The Sahara is one of the hottest areas in the world; the mean annual temperature can exceed 86 degrees F normally, and 122 degrees F in the hottest months. The temperature in the Sahara goes from one extreme to the other in the course of one day. The temperature drops dramatically at night and rises as the day progresses till it becomes scorching.
The Kalahari desert is located in Southern Africa and covers most of Botswana and parts of Namibia and South Africa. The Kalahari receives between 3 to 7.4 inches of rain annually. The word Kalahari is derived from the Tswana word “Kgala,” which means “a waterless place.” The dominant vegetation in this region are grasses, Acacia trees and thorny shrubs which have adapted to survive long drought periods of up to 10 months each year.
The Gobi desert is the fifth largest desert in the world. It covers parts of northern and northwestern China and parts of southern Mongolia. The Gobi desert is a cold desert due to its elevation, which is nearly 5,000 feet above sea level at some points. As such, there are occasional snow on the dunes and even more common frost formations.