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Hydrological Processes

  1. Donald A. Wilhite,
  2. Michael J. Hayes,
  3. Mark D. Svoboda

Published Online: 15 JAN 2013

DOI: 10.1002/9780470057339.vnn046

Encyclopedia of Environmetrics

Encyclopedia of Environmetrics

How to Cite

Wilhite, D. A., Hayes, M. J. and Svoboda, M. D. 2013. Drought. Encyclopedia of Environmetrics. 2.

Author Information

  1. University of Nebraska, Lincoln, NE, USA

Publication History

  1. Published Online: 15 JAN 2013


Drought is a naturally occurring event that is associated with virtually all climatic regions. There is no universal definition of drought since its characteristics and impacts vary by region and economic sector. Given its slow onset and other characteristics, including its spatial dimensions and duration, impacts are difficult to assess and have been, historically, poorly documented. These impacts are strongly influenced by a society's exposure to the hazard and the vulnerability of that society to the hazard. This vulnerability is continually changing in response to increasing population, land use changes, technology, government policies, and many other factors. Therefore, each drought event is superimposed on a society with differing vulnerabilities than existed when the previous drought event occurred. Drought impacts are increasing worldwide, both as a result of these changing vulnerabilities and, perhaps, because of an increase in the frequency, severity, and duration of drought events in association with a changing climate. To lessen societal vulnerability, it is imperative for nations to move away from crisis management approach to drought management and toward a more proactive, risk-based approach. Emphasis must be given to the development of improved drought monitoring and early warning systems and the delivery of this information to decision makers at all levels. It is also essential that vulnerability assessments be conducted in order to determine who and what is at risk and why. A final step is the identification and implementation of appropriate mitigation measures or actions that will reduce future impacts on economic sectors and population groups.


  • drought;
  • drought policy;
  • drought planning;
  • drought impacts;
  • drought risk management;
  • mitigation;
  • preparedness;
  • vulnerability;
  • natural hazards;
  • water planning