Uncertainty in design water levels due to uncertain bed form
roughness in the river Rhine


Warmink, J.J. and Booij, M.J. and Hulscher, S.J.M.H. and Klis, H. van der (2010) Uncertainty in design water levels due to uncertain bed form
roughness in the river Rhine.
In: Andreas Dittrich (Ed.), River flow 2010: proceedings of the [Fifth] International Conference on Fluvial Hydraulics. BAW, 1 . Bundesanstalt für Wasserbau, pp. 359-366. ISBN 9783939230007

open access
Abstract:Hydrodynamic river models are applied to design and evaluate measures for purposes such
as safety against flooding. The modeling of river processes involves numerous uncertainties, resulting in
uncertain model results. Knowledge of the type and magnitude of these uncertainties is crucial for a meaningful
interpretation of the model results. The aim of this study is to quantify the uncertainty due to the
hydraulic roughness predictor for the river bed in the main channel and assess its effect on the uncertainty
in the modelled water levels under design conditions. The uncertainty in the bed roughness consists of the
uncertainty between the different roughness predictors and the uncertainty within the roughness predictor
itself. We compared five roughness predictors, which determine the hydraulic resistance of the river bed
in the Dutch river Rhine, based on measurements of bedform characteristics and water levels for different
discharges. Generalized Extreme Value distributions have been fitted through the predicted roughness
values and extrapolated to the design return period. The results show that the 95% confidence interval for
the Generalized Extreme Value distributions the predicted Nikuradse roughness values under design conditions
ranges from 0.32 m to 1.03 m. This uncertainty is propagated through the model by means of a
Monte Carlo Simulation. The Monte Carlo analysis shows that the uncertainty in the hydraulic roughness
results in a 95% confidence interval for the water depth that range from 11.7 m to 12.4 m.
Item Type:Book Section
Copyright:© Bundesanstalt für Wasserbau
Engineering Technology (CTW)
Research Group:
Link to this item:http://purl.utwente.nl/publications/78716
Conference URL:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page

Metis ID: 268286