Contents

30 April 1993
Vol 260, Issue 5108

About The Cover

Satellite mosaic (1972-1990) of the River Nile delta. The geologic record of the delta provides a basis for understanding the impact of population growth and natural factors on land use. Accelerated loss of agriculture (vegetation shown in red) results from urban expansion (yellow), development of large sand dunes (pink), coastal erosion, and formation of salt pans (white, far right). Reclamation projects are draining the remaining lagoons and marshes (green). See page 628. [Image: Earth Satellite Corporation, using Landsat images]