Application to bay of Cartagena de Indias (Colombia)

1. Javier García Alba*, J.F. Bárcena, A. García , B. Pérez-Díaz, P. Núñez, S. Castanedo, R. Medina
ENVIRONMENTAL HYDRAULICS INSTITUTE “IHCANTABRIA”. UNIVERSIDAD DE CANTABRIA
IMPACT OF DREDGING PROCESSES IN TURBIDITY OF SEMI-
ENCLOSED WATER BODIES: APPLICATION TO BAY OF
CARTAGENA DE INDIAS (COLOMBIA)

2. 1. Why is this study necessary?
2. Starting data and scenarios
3. Turbidity analysis
4. Acknowledgements
Index

3. 1. Why is this study
necessary?
Colonial importance
Bay of Cartagena
de Indias
Natural barrier
Natural source of
sediments
17 km
9.5 km
Small tidal range
Tidal Prism= 16·106 m3

4. International
seaborne trade
Adaptation and adjustment of the access channel to the
Bay of Cartagena de Indias
Investments in port
infrastructure
Trade
agreements
Dispersion of sediments in the water column during dredging
operations
Bay of Cartagena de Indias
(Colombia)
ASSESSMENT!!
1. Why is this study
necessary?

5. 2. Starting data and
scenarios
Bathymetry
Starting Data
a)
b)
Dique Channel “Estudios e investigaciones de las obras de restauración
ambiental y de navegación del Canal del Dique”, (UNAL, 2007)

6. CFSR reanalysis system
Atmopheric data
(wind,pressure,
Heat fluxes)
Salinity and
temperature
Wind data Rafael Nuñez
Airport
COADS05 database (Da
Silva et al.)
“World Ocean Atlas 2005”
(WOA05) database
Astronomic
Tide
b)
a)
b)
TOPEX model
2. Starting data and
scenarios
Starting Data

7. Scenarios
Climate events
2. Starting data and
scenarios

8. IH-Dredge Methodology
+Delft3D (FLOW+MOR)
Coupling
3. Turbidity analysis
Methodology
Initial Conditions
Computational cell
Dredging path
Bathimetry, bottom geophysics
4. Módulos de dragado
Dredging area
Draga de succión en marcha

9. -Dispersion of dredging losses and Dique
cannel sediment contributions (same type
of sediment)
-9 scenarios: Combination of 3 types of year
(Niña, Mean y Niño) and 3 types of season
(wet, transition and dry).
-Dredging solid flow of 0,75 m3/s.
-Barge (volume of de 2000 m3). Overflow
when volumen>1600 m3 (from this
moment, a 5% material losses until to fill
the barge).
-Generated material in dredging process:
Silt of 8 micrometers and 2650 kg/m3
densty.
-Dump:6 nautic miles from the dredging
area.
3. Turbidity analysis
Methodology
Flow dredged (solid flow)
Dredging Path
Max Limit Depth (objetive of this dredging)
Depth= Depth – e* t
SS(Surface) = SS(Surface) +Overflow Material Losses (if it were posible in that t)
Volume collected in the barge= Volume collected in the barge + (e * x* y)
STOP
Trayec.Terminada?
Yes
No
NoYes
t<Tiempo Total
Dragado
Yes
t+t
SS losses in the dump area
Sediment Transport (DELFT3D)
Is the path finished?
t<Total Time Dredging
(Depth - e)<Max Limit Depth
-e: Mass dredge in each pass

10. Instantenaous
concentration
Spatial distribution of SS concentration provided
by material losses (kg/m3) during the dredging
process in the surface layer.
Scenario: year 1990 (Mean year)- Transition
season
t = 1 h t = 150 h
t = 300 h t = 430 h
3. Turbidity analysis

11. Spatial distribution of exceeding time (%) in the surface layer during the dredging process in year 1990
scenario (Mean year) on the wet season en la estación húmeda for SS concentrations greater than: a)
0,01 kg/m3; b) 0,02 kg/m3; c) 0,04 kg/m3; d) 0,08 kg/m3
Exceeding time (%)
a) b)
c) d)
Exceeding time:
Concentrations
3. Turbidity analysis

12. Channel modification
Depth spatial distribution (m) during
dredging process for the year 1990
(mean year) in the transition season
(dredging process video)
t = 1 h t = 150 h
t = 300 h t = 430 h
3. Turbidity analysis
Depth (m)

13. Comparison between SS concentration introduced by the
dredging and the SS provided by Dique channel
3. Turbidity analysis

14. Conclusions
-In the area to be dredged, the average SS concentration in the surface layer has
values ​​ranging from 0.048 kg/m3 (Niña year – wet season) to 0,074 kg/m3 ( Niño year –
transition season).
-In the dredging area, the maximum value of the temporal average concentration is
between 0,123 kg/m3 (Niña year-wet season and Mean year-dry season) and 0.178
kg/m3 (Niño year-transition season).
-Exceeding time of concentrations >0.02 kg/m3 is similar for all scenarios, whereas the
related area to the exceeding time of concentrations > 0.01 kg/m3, is bigger for
scenarios on the dry season due to hydrodynamic fenomena in the channel (higher
outflow in that zone).
-The discharge into the dump area has a very localized dispersion not reaching the
dredging area or inside the bay.
-Dredging material losses affect a localized area in the dredging zone. While the dredge
is working the SS concentration in this area due to its losses are greater than the
concentration provide by Dique channel. During Niña year the SS concentration coming
from Dique channel is much greater than the sediment contribution of the dredging
process. On the dry season it is lightly smaller.
3. Turbidity analysis

15. 4. Acknowledgements
Acknowledgements
-Aqua & Terra Consultores Asociados S.A.S.
-Plan Nacional de I+D+i (2013) del Ministerio de Ciencia e
Innovación (Proyecto CTM2012-32538).
-CFSR (Climate Forecast System Reanalysis, The National Centers for
Environmental Prediction NCEP).
-Rafael Nuñez Airport (wind data).
-“World Ocean Atlas 2005” (WOA05) database.
-COADS05 database.
-TOPEX/Poseidon System.

16. Javier García Alba*, J.F. Bárcena, A. García , B. Pérez-Díaz, P. Núñez, S. Castanedo, R. Medina
ENVIRONMENTAL HYDRAULICS INSTITUTE “IHCANTABRIA”. UNIVERSIDAD DE CANTABRIA
IMPACT OF DREDGING PROCESSES IN TURBIDITY OF SEMI-
ENCLOSED WATER BODIES: APPLICATION TO BAY OF
CARTAGENA DE INDIAS (COLOMBIA)