The role of episodic water level variations for the dynamics of Danube Delta coastal zone

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The role of episodic water level variations for
the dynamics of Danube Delta coastal
zone Sebastian Dan1,2 and Adrian Stanica1 1.
National Institute of Marine Geology and
Geoecology GeoEcoMar, Romania. 2. Delft
University of Technology, Faculty of Civil
Engineering and Geosciences, The Netherlands.
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• Outline
• Objective
• Study zone
• Methods
• - water level variations
• - aerial beach response
• Results
• - water level variations
• - aerial beach response
• Conclusions

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1. Objective
To identify the most vulnerable beach sectors to
the water level variations induced by storm
surges - water level - aerial beach response
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2. Study zone
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2. Study zone
Sulina
advance 5-10 m/year
Canalul cu sonda
erosion up to 20 m/year
Câsla Vadanei
Sf. Gheorghe
Sahalin
Zatoane
1 million m3/year
Periteasca
migration gt 20 m/year
Portita Inlet
-5m
erosion 1 m/year
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3. Methods
Water level variations - numerical modelling.
Process-based numerical model Delft-3D
- SWAN module waves - FLOW
module water level variations. Ten storm
scenarios based on 10 years of wind records -
from north to south-west - from 15 to 40
m/s - one extreme case.
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3. Methods
Aerial beach response - extension of flooding
10 profiles, 3 years (1995 1997)
Aerial beach
Height 0.67 2.52 m
MSL
Length 13.6 93 m
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4. Results
Water level variations
wind direction north wind speed 40 m/s
Water level variation expressed in centimetres
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4. Results
Water level variations
wind direction south wind speed 30 m/s
Water level variation expressed in centimetres
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4. Results
Water level variations
wind direction north-east wind speed 40
m/s
Water level variation expressed in centimetres
x coordinate (m)
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4. Results
Aerial beach response
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4. Results
Aerial beach response
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4. Results
Aerial beach response
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5. Conclusions

• Variability of the water level variation along
  the Danube Delta coast due to change in the coast
  orientation.
• Largest rates of flooding Sulina Sf. Gheorghe
  area, already vulnerable.
• A catastrophic event (north-easterly wind, 40
  m/s) would breach the dunes, with significant
  consequences
• - input of the salt water in a fresh water
• environment
• - destruction of infrastructure
• - potential flood of parts of the Sf. Gheorghe
• village.
• The floodable inland areas are part of the
• DD Biosphere Reserve.
• Need for rapid intervention on the most
• vulnerable parts of the Danube Delta coast.

Sulina
Sf. Gheorghe
Portita Inlet
Sahalin
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Acknowledgements EC FP6 no. 044122 project
Concepts and Science for Coastal Erosion
Management (CONSCIENCE) numerical
modeling. Romanian National Research Core
Programmes (1984 present) the field
measurements.