Africa is home to three deserts: the
and the Namib; together they comprise more than a quarter of the continent.
The Sahara is the largest desert in the world, covering part or all
of eleven African countries. Sahara
is derived from the Arabic word for desert. The Kalahari
is a cold, rocky desert in southern Africa. The Namib,
in southwest Africa, is one of the hottest, driest places on earth,
with less precipitation than even the Sahara.
is the strip of land that separates savanna from the desert. Sahel
comes from the Arabic
word for "edge" or "border" because it is the edge of the desert.
The Sahel is shrinking at an
alarming rate. Animals have been allowed to graze on its fragile land,
which as destroyed the vegetation. The people who live along the Sahel
have caused it to shrink by cutting trees and bushes for fuel. Without
the trees and bushes to hold it in place, the thin topsoil is of the
Sahel blown away, leaving stony land where neither grass nor crops
can grow. The Sahara
and the Kalahari Desert creep one hundred miles closer to one another
every year as desertification and erosion spread.