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Uncertainty Analysis in Watershed Modeling

Surface Water Hydrology

  1. Thorsten Wagener

Published Online: 15 JUL 2005

DOI: 10.1002/047147844X.sw1063

Water Encyclopedia

Water Encyclopedia

How to Cite

Wagener, T. 2005. Uncertainty Analysis in Watershed Modeling. Water Encyclopedia. 3:325–327.

Author Information

  1. The Pennsylvania State University, University Park, Pennsylvania

Publication History

  1. Published Online: 15 JUL 2005

Abstract

All watershed modeling studies unavoidably contain uncertain elements. This uncertainty is propagated into the model predictions and impacts subsequent decision-making. Main uncertainties include those stemming from a lack of understanding of the hydrologic system, the problem of identifying appropriate model structure and parameters, and uncertainties in the measured data. While many approaches exist that can be used for uncertainty analysis, little guidance is available to choose the best approach for a certain study. While available techniques are many, they can all be reduced to three fundamental steps: (1) define what constitutes a behavioral model; (2) find all the models that comply with this definition in the feasible parameter space; (3) propagate the predictions of all identified models into the output space while considering other uncertainties (e.g., in the forcing data). This three-step structure is used to describe and cluster current approaches.

Keywords:

  • watershed modeling;
  • uncertainty;
  • perceptual model;
  • model structure;
  • parameters