Drought -- National Drought Mitigation Center


Date of this Version



Natural and Technological Disasters: Causes, Effects and Preventive Measures. Edited by S.K. Majumdar, G.S. Forbes, E.W. Miller, and R.F. Schmalz.


© 1992, The Pennsylvania Academy of Science.


Drought has been a threat to human existence throughout history. Today, as in the past, drought alters the course of civilizations. It is not merely a physical phenomenon, but the result of an interplay between a natural event (precipitation deficiencies due to natural climatic variability on varying timescales) and the demand placed on water supply by human-use systems. Extended periods of drought have resulted in significant economic, environmental, and social impacts, including food supply disruptions, famine, massive soil erosion, migrations of people, and wars.