The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook Columbia Gazetteer American Heritage Coll.
Sparse vegetation is found in most parts of the Sahara, with the exception of the sand dune regions.
The mountains are deeply dissected and were in the past infamous for the shelter they provided to marauders preying on desert traffic. The Sahara has one of the harshest climates in the world. The desiccating and dust-laden winds are sometimes felt north and south of the desert, where they are variously known as sirocco, khamsin, simoom, and harmattan. The northern slopes of the Atlas Mts. intercept most of the moisture from winds blowing inshore from the Mediterranean Sea. 3 Border zones on the north and south, where the desert merges with the steppe, receive about 10 in.