Resumen de Valley Changes in the Mediterranean and America and Their Effects on Humans

Luna B. Leopold, Claudio Vita Finzi

• River valleys in the Mediterranean, the Near East, the southwestern United States, and Mexico have repeatedly alterned between alluviation and erosion, changing the availability of water and agricultural land. The timing and magnitude of the various episodes suggest that the principal cause is a shift in precipitation patterns. Human activity has distorted the severity and the initiation of these changes that have at times been beneficial and at other times detrimental to the local population