Why is Sahara a desert?

On earth, there are places that are too cold or too hot.  The variation of climate and land forms may be caused by the rotation and revolution of the earth.  Some of the land forms had been shaped millions of years ago.  This is what happened to Sahara desert.  It had undergone lots of changes before it was acclaimed as the largest desert in the world.

Sahara is located in Africa and runs through 11 countries.  Its temperature can soar up to 136 degrees Fahrenheit but at night time, it can drop to below freezing point.  We often believe that a desert is hot but actually deserts can be cold, too. As defined, a desert is a place which is inhabited by humans, an empty region or a lifeless area of water. This definition fits Sahara desert.

Sahara means desert in Arabic language.  It is called as such because of its land form.  It is a barren place that is composed of sand dunes and regs (plains covered with sand and gravel).  With the kind of landforms Sahara has, plants and trees could not survive, only a few of the living things such as some organisms or cacti.

Water is rare in Sahara, another characteristic of a desert. There is less than 10 inches of rain per year. These are also lakes but mostly salt lakes.  Before there is a river in Sahara but it dried up.  If a certain region has no water, people could not survive.  This is the reason why Sahara is not inhabited by men.

Sandstorm is also common in Sahara.  When the wind blows, curls of brown clouds of sand can be seen, the usual sight in a desert.  Sahara may be dry but it also hosts some animals such as antelopes, snakes, lizards, birds.  But usually they come out at night because the desert becomes colder.