HOW WAS THE SAHARA DESERT FORMED?

Until about 6,000 years ago, the Sahara in northern Africa was a fertile plain. 
Many animals roamed across the grassland. 
There were also many people, herding their animals from pasture to pasture or farming the land. 
Then the climate began to change. Less rain fell, and the dry land turned to desert.
Today, the Sahara is the earth’s largest desert. And it is growing in size every year.

Why does the land turn to desert?

About one-fifth of the earth’s land area is desert.
Each year, these desert areas of the world are becoming larger. As the soil dries up, the edges of the desert spread and the land can no longer provide food for grazing animals. This is caused partly by changes in the world’s climate. 
But it is made worse by people who have dug up the grassland for farming or allowed too many animals to graze on it.

When land is over-farmed or over- grazed, the topsoil turns to dust, which blows away in the wind. The layer of soil left behind is baked hard by the sun. In time, it cracks. Any rain that falls cannot soak in and flows away.

One of the areas where the desert has spread recently is the Sahel, an area south of the Sahara, in Africa. It is an area of grassland which has often suffered from drought, long periods of no rain. Since 1968, the Sahel has suffered from especially bad drought, as well as changes in the climate. The land has dried up and has begun to turn into desert.
Over-grazing has created more bare soil.
New wells were dug, but the surrounding land was grazed bare as people gathered with their animals. New crops were introduced and fields were no longer left to rest. The few remaining trees were cut down to be used for fuel. Winds from the Sahara blew away the dry topsoil of the Sahel and left barren sand. In the end, there was not enough grassland left to support the people who lived there. Some moved away, but millions of people and animals died in the years after 1968.

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