4-1 Discussion: Delineating Global Regions
The place theme of geography best explains how and why North Africa is categorized regionally with
Southwest Asia, separate from sub–Saharan Africa. North Africa is culturally, physiographically, and
linguistically different from sub-Saharan Africa. The extremely harsh climate of the Sahara Desert forms
the effective barrier, interrupted only by the Nile River, which separates North and sub-Saharan regions
of Africa. North Africa and Southwest Asia are both comprised of mostly arid desert land. Populations in
