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PHD THESIS
Department of Civil
and Environmental
Engineering
2015 - 2017
Method for Reduced
Uncertainty in Stage-
Discharge Curves
Supervisor:
Nils Rüther
Co-supervisor:
Jochen Aberle
Øyvind Pedersen
Background
Getting reliable stage-discharge data under
extreme flood conditions is essential for good
predictionsoffuturefloodevents.Atthesametime,
the discharge data used for prediction often have a
highlevelofuncertainty.Gettingmorereliableflood
predictions are potentially worth millions in saved
costs for construction of dams and infrastructure,
as well as in preventing damaging floods. This
thesis aims to develop methodology for reducing
the uncertainty in stage-discharge curves using
a hybrid-modelling approach. Hybrid-modelling
involves combining a physical scale-model with a
numerical CFD-model. The PhD-program is part
of the Flom-Q project, which goal is to create a
better flood-prediction framework forNorway. The
lower left figure shows a stage-discharge curve
used for calculating discharge from a measured
water level at a gauging station. Measurements
of the stage-discharge relations typically are done
for a range of discharges from low flow to flood
conditions. At larger floods,measuring discharges
directly can be both difficult and dangerous, and by
definition these floods are rarely occurring events.
Because of this, discharge data for extreme
floods often stem from stage-discharge curves
extrapolated well beyond the measured range.
The goal of this PhD is to develop a method to
obtain better data for the extrapolation.
This figure shows a scale-model of the
Eggafossen gauging station site
The above figure shows a visualization of the
Eggafossen CFD-model
Source: Di Baldassarre et al. 2012
PHD THESIS
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