Hot desert is the driest and hottest place on the earth. Hot deserts lie between 20° and 30° latitudes in both the hemispheres. They lie on the western parts of the continents. The hot deserts of the world are Sahara Desert, Arabian Desert, Thar Desert, Sonoran Desert, Kalahari Desert, Atacama Desert, and Western Australian Desert. Sahara desert is the largest hot desert in the world.
Climate of hot deserts is characterised by hot summers and cool winters. Diurnal range of temperature is greater than the annual range of temperature. Annual rainfall is less than 25 cm.
Vegetation in desert is sparse and very well adapted to the high temperature, less water and dry winds. Important plants of hot deserts are cactus, acacia, Joshua tree, baobab, palm tree, and prickly pear.
Wildlife of the desert is also adapted to the environment. Important animals of the desert are camel, addax, desert fox, gazelles, donkey, horse, lizard, beetle, wild gerbil, scorpion, etc.
Primitive nomadic tribes live in these areas, in small numbers and survive by hunting and food gathering.
The desert dwellers are Bushmen, Aborigines, Tuaregs, Bedouins, and Settled cultivators. Oasis is formed because of the presence of water that makes cultivation possible.
In oases, where conditions are more hospitable, people live in permanent settlements. Agriculture and animal rearing are the occupations of the people living in oasis.
Nile River is the source of life-sustaining water in the desert of Egypt. Agriculture is the main occupation in the Nile valley. The farmers are known as Fellahin.
Two types of irrigation are practiced in Nile Valley: basin irrigation, and perennial irrigation. Houses are made up of mud walls and the roofs are flat. Desertification takes place when a desert gradually spreads to the surrounding areas of semi-desert.
Excessive and irregular irrigation, intensive ploughing, decreasing underground water table, deforestation, overgrazing, erosion, growing population and climate change, etc., are main causes of desertification.
Effective measures should be taken to control desertification.