 
north africa and the middle east is a region of deserts. 
there are mountains and plateaus as well, but the desert most affects the 
life of the people. 
the largest desert on earth, the sahara, is located in northern africa and 
covers the southern portions of morocco, algeria, and libya. 
in addition, desert lands extend eastward to the red sea. 
beyond the red sea there is desert again. 
the arabian peninsula contains one of the largest true deserts in the 
world, the rub al[khali, which is known as the "empty quarter." 
(a true desert has no vegetation at all.) 
there are no settlements in the empty quarter and few people have ever 
crossed it. 
this region is a continuation of the sahara and part of a desert chain 
that extends through large parts of southwest asia some 5000 miles from the 
atlantic to the indian ocean. 
the middle east is probably the driest place on earth. 
the major economic problem that people living here have to face can be 
summarized in one word: water. 
although some areas may have a lot of rainfall, the rain is concentrated 
so that it falls over a short period of time, leaving the ground dry through 
most of the year. 
during the rainy period, the water flows into seasonal streams called 
wadis. 
this water runs off rapidly, carrying with it most of the topsoil. 
as a result the land is left in worse condition than if it had not rained 
at all. 
it is along the mediterranean coast and some of the other coasts, as well 
as in the mountains that rain falls most heavily during the rainy season. 
