dsd-int 2016 effects of deepening of the rotterdam waterway - grasmeijer
TRANSCRIPT
TIDE-INTEGRATED SEDIMENT TRANSPORT IN TIDAL CHANNELS AND EFFECT OF CHANNEL DEEPENING
Effect of deepening the Rotterdam Waterway on turbidity maximum
2 November 2016
© Arcadis 2016
Rotterdam Waterway Ship canal from Rotterdam to North Sea
Artificial mouth of river Rhine
Length of 20 km
Width 480-675 m
Depth 14.5-16 m below NAP
Started in 1866 (150 years!), opened in 1872
Stairway line (trapjeslijn) 1970
Closing off Haringvliet 1970
Flood protection system Maeslantkering (1997)
Mean tidal range 1.7 m
Discharge 500-4500 m3/s
Sand D50 = 200-350 µm
Mud 10-35%
Botlek
Hoek van Holland
© Arcadis 2016
Dredging volumes in Rotterdam Waterway 1970’s: ~2x106 m3 per year
2010’s: ~0.5x106 m3 per year
Change in dredging and disposal strategy
Staircase line (trapjeslijn)
Haringvliet closed off
© Arcadis 2016
Computed mud concentrations
Van Rijn (2007)
transport module
in Delft3D
(mud and sand)
Agrees with
measurements
50% discharge
1 mud fraction
1 sand fraction
© Arcadis 2016
Mud transport along Rotterdam Waterway is non-saturated transport over a mainly sandy bed
Mud concentrations in ETM are supplied by the river and from sea
Deepening increases salinity intrusion and causes larger peak flood velocities at seaward side of deepened stretch
Initially, deepening Nieuwe Waterweg around Botlek results in small landward shift of turbidity maximum but not in increase of maximum
Deepening results in larger sedimentation rates in harbour basins
However, deepening also results in slightly more mud import
Start MSc research: effects on bed composition and turbidity on long term (years)
Conclusions
© Arcadis 2016
Discharge as function of Rhine discharge
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
0 2000 4000 6000 8000 10000 12000 14000
Lo
kale
afv
oer
[m
3/s
]
Bovenrijnafvoer [m3/s]
Nieuwe Waterweg Nieuwe Maas Oude Maas