The Sahara is the world’s largest hot desert and third largest desert after Antarctica and Arctic. Sahara covers most parts of North Africa and it’s surface area is almost the same size as of China and the United States. Many of its sand dunes reach over 180 metres (590 ft) in height.
Around 2,5 million people live in Sahara, most of them in Morocco, Mauritania and Algerie. The dominant groups are Tuaregs, Berbers, Sahrawis, Moors and different ethnic groups like Tubu, Nubians, Zaghawa and Kanuri.
Most of Sahara is uninhabitable and desolate. The settlements are mostly located in the oases. The largest oases are located in the Northwest, Tafilalet (Morocco), Touggourt and Adrar (Algerie).
A small part of Sahara’s population live like nomads and wander with camels, sheep and goats, especially in the Western part and on high areas with vegetation.
An erg (also sand sea or dune sea, or sand sheet) is a large, flat area of shifting sand dunes.
The term takes its name from the Arabic word «arq», which means “dune field”.
A desert pavement covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobblesize.
A hamada is a type of desert landscape consisting of high, largely barren, hard, rocky plateaus with very little sand. Hamada is related to desert pavement.
An oasis is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source. Oases also provide habitat for animals and even humans if the area is big enough. The location of oases have been of critical importance for trade and transportation routes in desert areas; caravans must travel via oases so that supplies of water and food can be replenished.
People who live in an oasis must manage land and water use carefully; fields must be irrigated to grow plants like apricots, dates, figs, and olives. The most important plant in an oasis is the date palm, which forms the upper layer. These palm trees provide shade for smaller trees like peach trees, which form the middle layer. By growing plants in different layers, the farmers make best use of the soil and water. Many vegetables are also grown and some cereals, such as barley, millet, and wheat, where there is more moisture.