An analysis of the effects of parameter uncertainty in deterministic hydrologic models

The uncertainty in the output of deterministic models, due to the uncertainty in the parameters of the model, is analyzed and compared to current procedures of using average values for the uncertain parameters. The present analysis considers an analytical rainfall‐runoff flood frequency model where the infiltration parameter is considered as a stochastic variable. The same conceptual procedure can be used to analyze fixed but uncertain (unknown) parameters. The extension to analyzing parameter uncertainty in large simulation models is indicated, and the importance of such analyses is discussed.