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Hydrological Extremes

Extremes and Environmental Risk

  1. Richard W. Katz

Published Online: 15 JAN 2013

DOI: 10.1002/9780470057339.vah017.pub2

Encyclopedia of Environmetrics

Encyclopedia of Environmetrics

How to Cite

Katz, R. W. 2013. Hydrological Extremes . Encyclopedia of Environmetrics. 3.

Author Information

  1. National Center for Atmospheric Research, Boulder, CO, USA

Publication History

  1. Published Online: 15 JAN 2013


An accurate estimation of the probability of occurrence of an extreme hydrological event is often required for the effective development and management of water resources. Examples include characterizing extreme rainfall event magnitudes to predict urban runoff, determining river flow magnitudes to design a culvert or bridge opening at a road crossing, and determining the likely severity of a drought event during the design life of a water supply system. In each of these examples, an understanding of the hydrological response of a watershed is essential in order to obtain a reliable estimate of the relationship between extreme hydrological event magnitudes and the probability of these events occurring. The role of the statistical theory of extreme values is emphasized.


  • extreme value theory;
  • floods;
  • generalized extreme value distribution;
  • generalized Pareto distribution;
  • peaks over threshold;
  • probability-weighted moments;
  • quantile estimation;
  • regional frequency analysis;
  • return level