Observations from ERTS of overgrazing and cultivation impact on the earth's surface

ERTS-1 imagery was surveyed for cases of anthropogenic impact, similar to that in the Sinai, evidenced by the Sinai/Negev demarcation line. Reflectivities in several such cases were analyzed using ERTS computer compatible tapes. Sharp increases of surface reflectivity show the severe impact of overgrazing found in several places around the world. Agricultural cultivation can also result in pronounced change of reflectivities, as evidenced by the Montana, USA/Canada demarcation line. Such processes have probably been going on since prehistoric times, increasing with the human population and with the population of the grazing herds.