1.
Impact of peak discharge increase
on the channel pattern and
dynamics of the Yellow River
Filip Schuurman
2 November 2016

2.
26 mei 2016
The Yellow River
(Huang He)
 6th Longest river in the
World (5500 km)
 Large social, economic and
geographical value
 Dynamic river
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3.
26 mei 2016
Water stress in the Yellow River basin
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26 mei 20164
Water stress in the Yellow River basin

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26 mei 2016
Hydropower dams and basins
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26 mei 20166
Impact of a.o. hydropower dams

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26 mei 2016
South-North Water Transfer project
 Sedimentation in the hydropower reservoirs
 Water shortage, despite water storage in hydropower
reservoirs
 Water transfer from wet Yangzte River basin to dry Yellow
River basin
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26 mei 2016
Research question:
How does the higher discharge affect
the channel pattern and morphodynamics
in the Yellow River?
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26 mei 2016
Methods
 System analysis:
 Field data
 Satellite photography
 Computer simulations:
 Hydrodynamics + sediment transport + morphology
 Calibration + validation: 1999 - 2014
 Prediction future: 2015 - 2040
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26 mei 2016
Settings
 Curvilinear, structured grid
 2D depth-averaged
 Grid resolution sufficient to capture bars
 Annual hydrograph based on expected discharge
regulation scheme
 Sediment inflow equal to local transport capacity
 Fine sediment (0.11 mm)
 Engelund-Hansen
 Variable morphological factor
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26 mei 2016
Morphological factor
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26 mei 2016
Study reaches
 Two study reaches of about 50 km:
 Braiding
 Meandering
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Braiding reach Meandering reach

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26 mei 201613

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26 mei 2016
However…
 First results give static channels with only
morphodynamics in first years
 Dry-wet bank erosion mechanism is
insufficient
 Similar to earlier studies
(e.g. Schuurman et al., 2013)
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15.
26 mei 2016
Bank erosion in Delft3D
 Dry-wet bank erosion mechanism at maximum
 Boost of bank erosion by:
 Strong spiral flow (Espir = 2)
 Strong transverse bed slope effect (alpha = 0.2)
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26 mei 2016
Result: Braiding reach: 2000 m³/s

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26 mei 2016
Result: Braiding reach: 4000 m³/s

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Result: Meandering reach: 2000 m³/s

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26 mei 2016
Result: Bend cutoffs in meandering reach
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26 mei 2016
Result: Meandering reach
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26 mei 2016
Result: Effect on sedimentation and erosion
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26 mei 2016
Sensitivity: Bed slope parameter
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26 mei 2016
Sensitivity: Spiral flow parameterization
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26 mei 2016
Summary
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 Higher (peak) discharge had large effect on the
river pattern:
 Higher braiding intensity
 Transformation from meandering to braiding
 Severe sedimentation on the floodplains
 Without mitigation measures, the transfer of
water from the Yangtze River to the Yellow River
is expected to have large economic and social
impacts
 Modelling of channel dynamics required a ‘trick’
for bank erosion, which worked well