Jedrasik J', Kowalewski M', Oldakowski B', University of Gdansk, Institute of Oceanography Impact of

1
Jedrasik J., Kowalewski M., Oldakowski
B.,University of Gdansk, Institute of
OceanographyImpact of the Vistula River waters
on the Gulf of Gdansk during 1994-2002

• European Commission project EUROCAT
• European Catchments Changes and their Impact on
  the Coast
• Case Study VISCAT
• The Vistula River Catchment and the Baltic Sea
  Coastal Zone

2
Plan

• 1. The ecohydrodynamic model of the Baltic Sea
• General discription
• ProDeMo model
• algorithm modifications
• Calibration, verification, validation
• quality evaluation of the model
• chosen results

2. Impact of the Vistula River on the Gulf of
Gdansk - examples
3. Conclusions
3
The ecohydrodynamic model of the Baltic Sea
4
ProDeMo model
Atmosphere
8
16
17

• 1 nutrient uptake
• 2 grazing
• 3 phytoplank. resp.
• 4 phytoplank. decay
• 5 sedimentation
• 6 nutr. release f. sed
• 7atmospheric dep.
• 8 denitrification
• 9 mineralization
• 10 zooplankt. resp.
• 11 sed.of P ads. on particles,
• 12 detritus sed.
• 13 zooplankt. decay
• 14 nitrogen fixation
• 15 nutrient deposition
• processes influen. dissolved oxygen
• 16 reaeration,

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23
PHYTOPLANKTON
DISSOLVED OXYGEN
14
Blue-green algae
22
20
Spring diatoms
1
19
Autumn diatoms
3
Dinoflagellate
Water
Green algae
4
21
2
9
10
6
13
18
11
5
12
Active layer
NSED
PSED
SiSED
Inactive layer
15
15
15
Sediment
5
Calibration
based at stations P1, P110, ZN2 for 1994 - 2002
period
Verification
as asessment of behavior of the model
Validation
test how the model results fit the observation
data
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Monitoring stations at the southern Baltic
The hydrodynamic model is based on the POM
(Princeton Ocean Model). The numerical
application of the model has been embedded on two
nested grids 1 NM for the Gulf of Gdansk in 5
NM for the Baltic Sea. A sigma
transformation for 18 layers are used.
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Validation of the model station P1 z 0m
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Validation of the model station P1
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Observed and modelled vertical distribution of
the variable states during winter and summer
seasons in 2001
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Observed and modelled vertical distribution of
the variable states during winter and summer
seasons in 2001
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Observed and modelled vertical distribution of
the variable statesduring winter and summer
seasons in 2001
The vertical distributions of the modelled
parameters follows the observations, however
better agreements have been achieved in the upper
layer than in the layer below the halocline
(60-70 m).
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Quality of the ProDeMo model
An excellent agreement for salinity, dissolved
oxygen and temperature. Other compared
parameters lie in the good range except
nitrate nitrogen as acceptable and ammonium
nitrogen low satisfactory.
13
Mean concentrations of the modelled parameters
for 15th June 1999
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Variation in biomass and structure of
phytoplankton modelled for 15th June 1999
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Distribution of phytoplankton at Gdansk Deep
station P1 in period 1994 - 2002
The vegetation seasons start with the high blooms
of diatoms during the spring. During the summer
dinoflagellates and green algae dominates. The
blue-green algae are able to assimilate the
nitrogen from the atmosphere. Their appearance
varies from year to year since they prefer higher
water temperature and solar radiation. Autumn
diatoms starts to grow in September and they
dominate trough whole autumn.
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Annual input of the Vistula River into the Gulf
of Gdansk
Vistula the second largest river of the Baltic
Sea introduces into the Gulf of Gdansk 85 of
discharged fresh waters 90 of nitrogen
compounds (it takes part 15 of N
in the Baltic) 23 is retained at the Gulf
92 of phosphorus compounds (it
takes part 20 of P in the Baltic) 34
is retained at the Gulf
17
Distributions of N-NO3 and P-PO4 in crossection
through the Gulf of Gdansk from mouth of the
Vistula River to the station P1 at 4th March 1995
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Spreading of the Vistula watersat the Gulf of
Gdansk during 11 April 10 May 2000
The hydrodynamics influences on the nutrient and
phytoplankton distributions. During the spring
season influence of the Vistula River waters on
the nutrient concentrations are even at the open
waters of the Gulf of Gdansk. 11 April 10 May
2000, the main pathway of the Vistula River water
- the North-West direction.
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Sequence of surface distribution of
phytoplankton biomass, nitrates and phosphates
at the Gulf of Gdansk between February 22
March 27 1995
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Conclusions
ProDeMo model calibrated, verified and
validated using monitoring data for 9 years
period 1994-2002, resulted in the model obtained
evidences (high statistical evaluation) which
permit to consider it as reliable tool for
studding the coastal processes in the Gulf of
Gdansk. The model has properly described the
seasonal distribution of nutrients, temperature
and dissolved oxygen, however near the bottom it
was overestimated. Other compared parameters
lie in the good range of quality of model except
nitrate nitrogen as acceptable and ammonium
nitrogen low satisfactory. The biomass
distributions of the five phytoplankton groups as
well as time and places of their blooms appeared
reliable.
Impact of the Vistula River on the Gulf of Gdansk
From among various effects of the Vistula River
discharge on the environmental state of the
coastal waters are pathways of the Vistula
River waters in the Gulf temporal and spatial
dynamics of nutrients blooms and seasonal
variations of phytoplankton biomass