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130 Fuzzy Sets in Rainfall/Runoff Modeling

Part 11. Rainfall-Runoff Modeling

  1. András Bárdossy

Published Online: 15 APR 2006

DOI: 10.1002/0470848944.hsa137

Encyclopedia of Hydrological Sciences

Encyclopedia of Hydrological Sciences

How to Cite

Bárdossy, A. 2006. Fuzzy Sets in Rainfall/Runoff Modeling. Encyclopedia of Hydrological Sciences. 11:130.

Author Information

  1. Universität Stuttgart, Institut für Wasserbau, Stuttgart (Vaihingen), Germany

Publication History

  1. Published Online: 15 APR 2006


Fuzzy sets offer an alternative to statistical methods to quantify uncertainties in modeling natural systems. Three types of applications for hydrological modelling can be considered:

  • the quantification of the uncertainties related to inexact knowledge of the model parameters that describe the underlying hydrological processes using fuzzy numbers and the extension principle
  • alternative description of individual hydrological processes using fuzzy rules
  • introduction of model performance measures which reflect soft information coded with fuzzy membership functions.

One of the major problems in the application of fuzzy sets is the assessment of the membership functions. Model parameters and performance measures are usually estimated subjectively. Fuzzy rules can be assessed using automated learning algorithms. Examples show that fuzzy sets, if they are applied in the combination with hydrological expertise, can be well used for rainfall runoff modelling.


  • fuzzy sets;
  • uncertainty;
  • rainfall runoff modelling