the role of episodic water level variations for the dynamics of danube delta coastal zone sebastian...
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The role of episodic water level variations for the dynamics of Danube Delta coastal zone
Sebastian Dan1,2 and Adrian Stănică1
1. National Institute of Marine Geology and Geoecology — GeoEcoMar, Romania.
2. Delft University of Technology, Faculty of Civil Engineering and Geosciences, The Netherlands.
Outline:
1. Objective
2. Study zone
3. Methods - water level
variations - aerial beach
response
4. Results: - water level variations- aerial beach response
5. Conclusions
1. Objective
To identify the most vulnerable beach sectors to the water level variations induced by storm surges:
- water level - aerial beach response
2. Study zone
Turkey
Ukraine
Russia
BLACK SEABLACK SEA
DanubeDelta
Bul
garia
Ro
ma
nia
10 km
Sulina
Sf. Gheorghe
2. Study zone
PortiţaInlet
Canalul cu sondă
CâşlaVădanei
Zătoane
Periteaşca
-5m
-10m
Sahalin
advance5-10 m/year
erosionup to 20 m/year
migration> 20 m/year
erosion1 m/year
1 million m3/year
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.
3. Methods
Aerial beach response:- extension of flooding – 10 profiles, 3 years (1995 –
1997)
MSL
Aerial beach
Height0.67 – 2.52 m
Length13.6 – 93 m
4. Results
Water level variations
Sulina
Sf. Gheorghe
x106
4.98
4.97
4.96
4.95
4.94
4.3 4.4 4.5 4.6 4.7 4.8 x10 5
x coordinate (m)
y co
ord
ina
te (
m)
50
45
40
35
30
25
20
15
10
5
0
(m)
N
wind direction:
north
wind speed:40 m/s
Water levelvariation expressed in centimetres
4. Resultsy
coo
rdin
ate
(m
)
Sulina
Sf. Gheorghe
4.3 4.4 4.5 4.6 4.7 4.8 x10 5
50
45
40
35
30
25
20
15
10
5
0
(m)x106
4.98
4.97
4.96
4.95
4.94
x coordinate (m)
wind direction:
south
wind speed:30 m/s
Water level variations
Water levelvariation expressed in centimetres
N
4. Results
Sulina
Sf. Gheorghe
c)y co
ord
ina
te (
m)
x106
4.98
4.97
4.96
4.95
4.94
4.3 4.4 4.5 4.6 4.7 4.8 x10 5
50
45
40
35
30
25
20
15
10
5
0
(m)
x coordinate (m)
wind direction:
north-east
wind speed:40 m/s
Water level variations
Water levelvariation expressed in centimetres
N
4. Results
Aerial beach response
1995
-40
-20
0
20
40
60
80
100
P1 P2 P3 P4 P5 P6 P8 P9 P10
len
gth
of t
he
flo
de
d p
rofil
e (
%)
N40 NE28 NE40 E19 SE15 S30 SW19
4. Results
Aerial beach response
1996
-40
-20
0
20
40
60
80
100
P1 P2 P3 P4 P5 P6 P7 P8 P9 P10
len
gth
of t
he
flo
de
d p
rofil
e (
%)
N40 NE28 NE40 E19 SE15 S30 SW19
4. Results
Aerial beach response
1997
-40
-20
0
20
40
60
80
100
P1 P3 P4 P5 P6 P7 P8 P9 P10
leng
th o
f the
flod
ed p
rofil
e (%
)
N40 NE28 NE40 E19 SE15 S30 SW19
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
Sahal
in
PortiţaInlet
-5m
-10m
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.