A dried up river filled with sand winds its way across the desert near Gos Beida in eastern Chad
A dried up river filled with sand winds its way across the desert near Gos Beida in eastern Chad June 5, 2008. Africa's Sahel region suffers from desertification as fertile land gives way to sandy expanses creeping ever southward, compounding problems in a region already affected by wars and rebellions, many of them driven by competition for scant resources. Wednesday was U.N. World Environment Day. REUTERS/Finbarr O'Reilly (CHAD)