ESIA Albania Annex 9 - Sediment Dispersion Modelling

ESIA Albania 

Annex 9 - Sediment Dispersion Modelling

Trans Adriatic Pipeline – TAP, ESIA Albania, Annex 9 - Sediment Dispersion Modelling 

AAL00-ERM-641-Y-TAE-1010, Rev.: 01 / at05, Page 2 of 278 

TAP (Trans Adriatic Pipeline) 

Sediment dispersion study at the 

Albanian landfall site



TAP (Trans Adriatic Pipeline) 

Sediment dispersion study at the 

Albanian landfall site 

Via Pomba 23 

I-10123 Torino 

Italia 

Tel: +39 011 56 24 649 

Fax: +39 011 56 20 620 

dhi-italia@dhi-italia.it 

www.dhi-italia.it 

Client 

Client’s representative 

ERM, TAP 

Alberto Sambartolome 

Javier Odriozola 

Project 

Project No. 

TAP (Trans Adriatic Pipeline): sediment dispersion 

study at the Albanian landfall site 

22700172-01-00101 

Authors 

Paola Letizia 

Date 

Approved by 

29 May 2012 

Andrea Pedroncini 

01 Final Report PLE ANP ANP MAY 12 

Revision Description by Verified Approved Date 

Key words 

Representative meteomarine conditions 

Dredging release rate 

Sediment plume 

Classification 

Open 

Internal 

Proprietary 

Distribution: 

ERM, TAP: 

DHI Italia: 

Alberto Sambartolome 

Luisa Di Chele 

No of copies 

1 (pdf) 

1 (pdf)



CONTENTS 

1 INTRODUCTION ........................................................................................................... 1 

2 OFFSHORE METEOMARINE CONDITIONS ................................................................ 2 

2.1 Wind climate offshore the Albanian Coast ..................................................................... 2 

2.2 Wave climate offshore the Albanian landfall site............................................................ 6 

2.3 Tidal conditions ........................................................................................................... 12 

2.4 Currents from the general circulation of the Adriatic Sea, temperature and salinity ..... 13 

2.4.1 Currents, temperature and salinity offshore the Albanian landfall site .......................... 15 

3 REPRESENTATIVE METEOMARINE SCENARIOS ................................................... 23 

4 3D HYDRODYNAMIC MODEL .................................................................................... 31 

4.1 Bathymetric data, model domain and resolution .......................................................... 31 

4.2 Scenario 1: results ...................................................................................................... 35 



4.5 Considerations on tidal currents .................................................................................. 58 

5 3D SEDIMENT DISPERSION MODEL ........................................................................ 60 

5.1 Methodological approach ............................................................................................ 60 

5.1.1 Selection of representative points for the sediment release ......................................... 60 

5.1.2 Dredging rate, release rate, settling velocity ................................................................ 62 

5.1.3 Model bathymetries ..................................................................................................... 65 

5.2 Assumptions on background suspended sediment concentration ............................... 69 




5.6 Settling of fine sediment in the model domain ............................................................. 80 

5.7 Settling of sand in the model domain ........................................................................... 81 

6 CONCLUSIONS .......................................................................................................... 82 

7 REFERENCES ........................................................................................................... 84 

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1 INTRODUCTION 

The scope of the work is to study, by means of numerical modelling, the 

sediment release and dispersion during the construction phase of the Trans 

Adriatic Pipeline (TAP). The present study is part of the Environmental and Social 

Impact Assessment (ESIA) for the offshore part of the Albanian landfall of the 

TAP. 

The pipeline is planned to go from Italy (Puglia) to Albania, covering a distance 

of more than 100 km. Figure 1-1 illustrates the pipeline route. 

Figure 1-1 Illustration of the pipeline route. Source: Google Earth 

In Chapter 2 the analysis of the offshore meteomarine data is illustrated. In 

particular, the available data of wind, waves, tide, currents from the general 

circulation of the Adriatic Sea (the so called “baroclinic currents”), temperature 

and salinity are described. The analysis and processing of these raw data have 

led to the identification of representative meteomarine conditions for the 

Albanian landfall site. 

Based on these analyses, three representative scenarios have been selected 

(Chapter 3). The assumptions and the results of the hydrodynamic and sediment 

dispersion models are illustrated in Chapters 4 and 5. 

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2 OFFSHORE METEOMARINE CONDITIONS 

The scope of this chapter is to provide a description of the available data of the 

meteomarine conditions offshore the Albanian landfall site of the TAP. In 

particular, the following chapters describe the wind and wave conditions, both 

yearly and seasonal, tidal variations and the circulation in the southern Adriatic 

Sea (baroclinic currents). 

2.1 Wind climate offshore the Albanian Coast 

The database used to analyse the wind climate conditions offshore the Albanian 

coast comes from the “Wind and Wave Mediterranean Atlas” [1] which is the 

result of the Medatlas project led by a consortium of six companies located in 

France, Italy and Greece between 1999 and 2004. 

This electronic atlas provides data of univariate and bivariate statistics, yearly 

and seasonal, of wind and wave (speed/height and direction). In particular, the 

reference station used in the present study is located at the point of 

geographical coordinates LON 19° LAT 41°, as shown in Figure 2-1, 30 km 

north-west of the Albanian landfall site. 

Figure 2-1 Location of point (LON 19° LAT 41°) in the Mediterranean Atlas. Source: 

“Wind and Wave Mediterranean Atlas” [1] 

The available wind data are illustrated in a scatter table of wind speed vs. wind 

direction (Table 2-1) and in a yearly wind rose (Figure 2-2). The data are also 

represented in seasonal wind roses (Figure 2-3). 

The analysis of wind data, as wind speed and directions, shows that the most 

frequent winds come from south-east while the strongest winds (maximum wind 

speed higher than 16 m/s) come from the sector around south (165° N to 

195°N). 

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Also the north-west sector is important in connection with frequency of 

occurrence; the importance of these directions is mainly observable during the 

summer season, when this sector becomes prevalent. 

Table 2-1 

Yearly wind climate – scatter table of wind speed vs. wind direction. Source: 

“Wind and Wave Mediterranean Atlas” [1] 

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Figure 2-2 Yearly wind rose. Source: the rose is processed by DHI on the basis of wind 

data coming from “Wind and Wave Mediterranean Atlas” [1] 

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Figure 2-3 Seasonal wind roses. Source: the roses are processed by DHI on the basis of 

wind data coming from “Wind and Wave Mediterranean Atlas” [1] 

The “Wind and Wave Mediterranean Atlas” [1] database is a powerful tool to 

simulate the wind climate at a certain site but it cannot simulate the real 

variability of wind speed and wind direction over a limited time window. 

For the numerical modelling of representative meteomarine conditions (Chapter 

4), the wind data are therefore taken from another database. In particular, the 

wind model realised by DHI for the Integrated Project Water and Global Change 

(WATCH, 2007-2011) [2] has been used. This project, funded under the EU FP6, 

brings together the hydrological, water resources and climate communities, to 

analyse, quantify and predict the components of the current and future global 

water cycles and related water resources states, evaluates their uncertainties 

and clarifies the overall vulnerability of global water resources related to the 

main societal and economic sectors. 

Within the framework of the Integrated Project Water and Global Change 

(WATCH, 2007-2011) [2], also the setup of a global wind model was previewed; 

in particular for this model the simulation was executed with the newest version 

of the HIRHAM regional climate model using the ERA Interim as driving field 

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covering the period from January 2000 to July 2009. This simulation was also 

executed in a restart every day mode in order to stay very close to the driving 

field. 

The domain has an extension of 302 x 202 grid cells and covers the whole 

Europe (Figure 2-4). The velocity components U and V are computed in the 

HIRHAM model according to the grid projection. An additional post processing 

was done on the wind vectors to fit them to the meridional (V component) and 

zonal (U component) coordinate system of the Earth. Wind speed is referred to a 

quote of 10 m and represents a mean value over an hour. 

Figure 2-4 Image of one time step of the wind model. Source: Integrated Project Water 

and Global Change (WATCH, 2007-2011) [2] 

2.2 Wave climate offshore the Albanian landfall site 

The “Wind and Wave Mediterranean Atlas” [1] database has also been used to 

analyse the offshore wave climate. 

The wave statistics are illustrated in a scatter table of wave height vs. wave 

direction (from Table 2-2 to Table 2-6) and wave roses (Figure 2-5 and Figure 

2-6), both yearly and seasonal. 

The analysis of wave data, such as significant wave height and directions, shows 

that the highest waves come from south-south-west (maximum wave heights 

ranging from 4.0 and 5.0 m). Together with the waves from the south-southwest 

sector, the north-west sector is characterized by a high frequency of 

incoming waves. 

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Table 2-2 

Yearly wave climate – scatter table of wave height vs. wave direction. 

Source: “Wind and Wave Mediterranean Atlas” [1] 

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Figure 2-5 Yearly wave rose. Source: the rose is processed by DHI on the basis of wave 

data coming from “Wind and Wave Mediterranean Atlas” [1] 

The seasonal trend follows, in general, the same yearly behaviour apart from the 

summer season. In particular during the winter/autumn months the waves from 

the south-south-west sector are particularly relevant, characterized by high and 

frequent waves. During the summer months both the highest and most frequent 

waves come from north-west. 

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MEAN WAVE DIRECTION [°N] 




Table 2-3 

Winter wave climate – scatter table of wave height vs. wave direction. 


SIGNIFICANT WAVE HEIGHT [M] 

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 

0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 

0 15 0.000 0.201 0.201 0.201 0.100 0.100 0.100 0.000 0.100 0.000 0.000 0.000 0.000 0.000 1.0 

15 30 0.100 0.201 0.703 0.502 0.602 0.301 0.301 0.201 0.100 0.000 0.000 0.000 0.000 0.000 3.0 

30 45 0.100 0.402 0.301 0.301 0.301 0.402 0.201 0.301 0.201 0.000 0.100 0.000 0.000 0.000 2.6 

45 60 0.100 0.602 0.602 0.602 0.402 0.402 0.201 0.100 0.201 0.000 0.201 0.000 0.000 0.000 3.4 

60 75 0.100 0.301 0.402 0.602 0.402 0.100 0.100 0.100 0.100 0.000 0.000 0.000 0.000 0.000 2.2 

75 90 0.000 0.301 0.201 0.402 0.100 0.100 0.000 0.000 0.000 0.100 0.000 0.000 0.000 0.000 1.2 

90 105 0.000 0.100 0.201 0.100 0.100 0.100 0.000 0.100 0.100 0.100 0.000 0.000 0.000 0.000 0.9 

105 120 0.000 0.100 0.100 0.100 0.000 0.000 0.000 0.000 0.100 0.100 0.000 0.000 0.000 0.000 0.5 

120 135 0.100 0.100 0.201 0.100 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.6 

135 150 0.000 0.100 0.402 0.100 0.100 0.100 0.000 0.100 0.000 0.100 0.000 0.000 0.000 0.000 1.0 

150 165 0.100 0.301 0.402 0.502 0.301 0.402 0.201 0.100 0.100 0.100 0.000 0.000 0.000 0.000 2.5 

165 180 0.301 0.602 0.904 1.104 0.803 0.803 0.602 0.502 1.004 0.402 0.301 0.301 0.100 0.100 7.7 

180 195 0.301 1.406 2.811 2.610 2.008 2.410 1.707 1.908 1.707 1.104 0.502 0.301 0.301 0.100 19.1 

195 210 0.703 2.008 2.108 1.506 1.305 1.205 1.104 0.602 1.104 0.502 0.301 0.301 0.100 0.000 12.9 

210 225 0.602 1.205 1.004 0.803 0.803 0.502 0.402 0.301 0.402 0.301 0.100 0.100 0.000 0.000 6.5 

225 240 0.301 0.301 0.402 0.402 0.301 0.100 0.100 0.000 0.201 0.100 0.000 0.000 0.000 0.000 2.2 

240 255 0.301 0.402 0.402 0.201 0.201 0.100 0.000 0.100 0.100 0.000 0.000 0.000 0.000 0.000 1.8 

255 270 0.201 0.502 0.402 0.402 0.201 0.100 0.000 0.100 0.000 0.100 0.000 0.000 0.000 0.000 2.0 

270 285 0.201 0.301 0.402 0.402 0.301 0.100 0.100 0.000 0.100 0.100 0.000 0.000 0.000 0.000 2.0 

285 300 0.402 0.602 0.602 0.402 0.301 0.201 0.100 0.100 0.100 0.100 0.100 0.000 0.000 0.000 3.0 

300 315 2.108 3.414 1.908 1.104 0.602 0.201 0.301 0.201 0.000 0.000 0.000 0.000 0.000 0.000 9.8 

315 330 1.707 1.807 1.305 1.707 0.602 0.201 0.100 0.100 0.100 0.000 0.000 0.000 0.000 0.000 7.6 

330 345 0.402 0.602 0.803 0.703 0.301 0.301 0.201 0.100 0.100 0.100 0.000 0.000 0.000 0.000 3.6 

345 360 0.100 0.602 0.602 0.301 0.301 0.201 0.100 0.100 0.100 0.100 0.000 0.000 0.000 0.000 2.5 

8.23 16.47 17.37 15.16 10.54 8.43 5.92 5.12 6.02 3.41 1.61 1.00 0.50 0.20 100.00 

Table 2-4 

Summer wave climate – scatter table of wave height vs. wave direction. 



0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 

0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 

0 15 0.101 0.101 0.201 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.4 

15 30 0.101 0.201 0.201 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.6 

30 45 0.101 0.302 0.201 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.7 

45 60 0.000 0.201 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.4 

60 75 0.101 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.3 

75 90 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

90 105 0.000 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

105 120 0.000 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

120 135 0.000 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

135 150 0.000 0.201 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.3 

150 165 0.101 0.504 0.201 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.0 

165 180 0.201 0.806 0.705 0.604 0.201 0.201 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.8 

180 195 0.906 3.424 2.618 1.611 0.806 0.504 0.201 0.101 0.101 0.101 0.000 0.000 0.000 0.000 10.4 

195 210 2.518 4.935 2.316 1.108 0.504 0.201 0.201 0.000 0.101 0.000 0.000 0.000 0.000 0.000 11.9 

210 225 2.820 1.813 1.108 0.201 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 6.1 

225 240 1.108 0.403 0.403 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.0 

240 255 0.604 0.403 0.403 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.5 

255 270 0.504 0.403 0.504 0.201 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.6 

270 285 0.806 0.604 0.504 0.201 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.1 

285 300 0.604 0.806 0.906 0.403 0.302 0.101 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.2 

300 315 2.115 3.323 2.216 2.014 0.806 0.403 0.201 0.101 0.000 0.000 0.000 0.101 0.000 0.000 11.3 

315 330 5.337 10.171 7.351 4.532 1.913 1.309 0.403 0.201 0.201 0.101 0.000 0.000 0.000 0.000 31.5 

330 345 1.410 2.518 2.618 1.108 0.504 0.201 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 8.4 

345 360 0.504 0.806 0.806 0.403 0.101 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.6 

20.04 32.43 23.87 12.99 5.34 3.02 1.21 0.40 0.40 0.20 0.00 0.10 0.00 0.00 100.00 

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Table 2-5 

Spring wave climate – scatter table of wave height vs. wave direction. 



0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 

0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 

0 15 0.000 0.204 0.204 0.306 0.102 0.000 0.102 0.102 0.000 0.000 0.000 0.000 0.000 0.000 1.0 

15 30 0.102 0.613 0.511 0.511 0.204 0.409 0.102 0.102 0.000 0.000 0.000 0.000 0.000 0.000 2.6 

30 45 0.102 0.409 0.613 0.204 0.204 0.204 0.204 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.9 

45 60 0.102 0.204 0.409 0.511 0.204 0.102 0.204 0.204 0.000 0.000 0.000 0.000 0.000 0.000 1.9 

60 75 0.102 0.204 0.204 0.204 0.204 0.204 0.102 0.102 0.102 0.000 0.000 0.000 0.000 0.000 1.4 

75 90 0.000 0.102 0.000 0.000 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

90 105 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0 

105 120 0.000 0.000 0.000 0.000 0.102 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

120 135 0.000 0.102 0.000 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.2 

135 150 0.000 0.102 0.102 0.204 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.4 

150 165 0.000 0.102 0.306 0.000 0.204 0.102 0.000 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.8 

165 180 0.306 0.715 0.613 1.124 1.124 0.409 0.306 0.000 0.204 0.102 0.102 0.000 0.102 0.000 5.1 

180 195 0.919 3.677 3.882 4.086 2.656 2.043 1.124 1.226 1.124 0.919 0.409 0.204 0.000 0.000 22.3 

195 210 2.349 4.494 3.882 2.962 1.226 1.021 0.409 0.306 0.409 0.306 0.102 0.000 0.000 0.000 17.5 

210 225 1.839 2.247 1.124 1.124 0.409 0.204 0.204 0.102 0.000 0.000 0.102 0.000 0.000 0.000 7.4 

225 240 0.715 0.511 0.306 0.409 0.102 0.204 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.2 

240 255 0.409 0.409 0.306 0.204 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.4 

255 270 0.511 0.715 0.306 0.306 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.9 

270 285 0.511 0.409 0.306 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.3 

285 300 0.613 1.124 0.715 0.409 0.204 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.2 

300 315 2.043 3.575 2.043 1.124 0.511 0.204 0.204 0.000 0.102 0.000 0.000 0.000 0.000 0.000 9.8 

315 330 1.634 3.166 2.554 0.919 0.919 0.613 0.102 0.000 0.000 0.000 0.000 0.000 0.000 0.000 9.9 

330 345 0.409 0.817 0.817 0.715 0.409 0.102 0.204 0.204 0.102 0.000 0.000 0.000 0.000 0.000 3.8 

345 360 0.306 0.919 0.919 0.511 0.204 0.306 0.102 0.102 0.102 0.000 0.000 0.000 0.000 0.000 3.5 

12.97 24.82 20.12 16.04 9.30 6.33 3.37 2.55 2.15 1.33 0.72 0.20 0.10 0.00 100.00 

Table 2-6 

Autumn wave climate – scatter table of wave height vs. wave direction. 



0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 

0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 

0 15 0.100 0.300 0.400 0.200 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.1 

15 30 0.200 0.701 0.601 0.300 0.200 0.000 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.1 

30 45 0.300 0.501 0.501 0.200 0.200 0.100 0.100 0.000 0.100 0.000 0.000 0.000 0.000 0.000 2.0 

45 60 0.200 0.701 0.601 0.400 0.100 0.200 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.2 

60 75 0.000 0.400 0.200 0.200 0.100 0.100 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.1 

75 90 0.100 0.100 0.100 0.100 0.100 0.000 0.000 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.6 

90 105 0.100 0.100 0.100 0.000 0.000 0.000 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.4 

105 120 0.000 0.100 0.200 0.000 0.000 0.100 0.000 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.5 

120 135 0.000 0.200 0.200 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.5 

135 150 0.200 0.400 0.100 0.000 0.100 0.100 0.100 0.000 0.100 0.000 0.000 0.000 0.000 0.000 1.1 

150 165 0.100 0.200 0.400 0.400 0.200 0.100 0.100 0.100 0.200 0.100 0.000 0.000 0.000 0.000 1.9 

165 180 0.400 1.001 1.001 1.802 1.101 0.701 0.701 0.501 0.901 0.400 0.300 0.200 0.100 0.000 9.1 

180 195 1.602 2.503 3.403 3.303 2.803 2.302 1.602 1.301 1.301 0.701 0.501 0.200 0.200 0.100 21.7 

195 210 1.702 3.203 2.603 2.202 1.602 0.901 0.801 0.601 0.801 0.300 0.100 0.100 0.100 0.000 15.0 

210 225 1.201 1.602 1.101 1.001 0.601 0.300 0.400 0.200 0.200 0.000 0.100 0.000 0.000 0.000 6.7 

225 240 0.300 0.501 0.601 0.501 0.200 0.100 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.3 

240 255 0.300 0.601 0.400 0.200 0.300 0.100 0.200 0.000 0.100 0.000 0.000 0.000 0.000 0.000 2.2 

255 270 0.200 0.300 0.300 0.300 0.200 0.100 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.5 

270 285 0.300 0.400 0.300 0.200 0.100 0.100 0.100 0.000 0.100 0.000 0.000 0.000 0.000 0.000 1.6 

285 300 0.501 0.601 0.300 0.300 0.100 0.100 0.100 0.100 0.100 0.100 0.000 0.000 0.000 0.000 2.3 

300 315 1.401 2.102 1.001 0.701 0.300 0.200 0.100 0.100 0.100 0.100 0.100 0.000 0.000 0.000 6.2 

315 330 2.002 3.403 2.202 1.301 0.601 0.400 0.100 0.100 0.200 0.100 0.000 0.000 0.000 0.000 10.4 

330 345 0.901 1.201 1.101 0.601 0.300 0.100 0.100 0.100 0.100 0.100 0.000 0.000 0.000 0.000 4.6 

345 360 0.400 0.801 0.601 0.501 0.300 0.100 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.7 

12.51 21.92 18.32 14.81 9.61 6.21 5.01 3.30 4.30 1.90 1.10 0.50 0.40 0.10 100.00 

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Figure 2-6 Seasonal wave roses. Source: the roses are processed by DHI on the basis of 

wave data coming from “Wind and Wave Mediterranean Atlas” [1] 

The “Wind and Wave Mediterranean Atlas” [1] also provides the scatter table of 

wave height vs. wave period, as shown in Table 2-7. The table will be used to 

associate a reliable peak wave period to the modelled wave conditions (Chapter 

3). 

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Table 2-7 

Yearly scatter table of wave height vs. peak wave period. Source: “Wind and 

Wave Mediterranean Atlas” [1]. 

2.3 Tidal conditions 

Tide analysis has been carried out by means of the tool MIKE C-MAP, developed 

by DHI (Danish Hydraulic Institute) [5]. This tool provides, together with nautical 

charts data, water level time series (astronomical tide variations) for a huge 

number of tidal stations worldwide. Both information are based on Admiralty 

Charts and Admiralty Tide Tables. 

The tidal station used as reference for the present study is Durres, about 60 km 

north of the Albanian landfall site. 

Figure 2-7 illustrates the astronomical tide cycle, in relation to a period which 

can be considered representative of the local average tidal conditions. As shown 

in the figure, the tide is semi-diurnal (two highs and two lows every day). During 

Spring Tide conditions the tide amplitude is in the order of 0.38 m, while during 

Neap Tide conditions the tide amplitude does not exceed 0.18 m. 

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Figure 2-7 Astronomical tide cycle for the Durres C-MAP station. Source: the time series 

is extracted from the database available in the tool MIKE C-MAP, part of DHI 

software package [5], station: Durres, period: 01/12/2010-31/12/2010 

2.4 Currents from the general circulation of the Adriatic Sea, temperature 

and salinity 

The analysis of currents from the general circulation of the Adriatic Sea 

(baroclinic currents), together with the analysis of temperature and salinity, has 

been carried out by processing data coming from the Mediterranean Forecasting 

System (MFS) database which is available within the framework of MyOcean EU 

Project [3]. 

MFS is a 3D global circulation model that provides daily analyses and 10-day 

forecasts of currents, temperature and salinity fields for the entire Mediterranean 

Sea at approximately 6.5 km resolution. MFS model is widely considered the 

state of the art of the models aiming at simulating the Mediterranean circulation. 

Figure 2-8 illustrates the domain of the MFS Mediterranean circulation model 

through an example of surface temperature distribution over the whole basin, 

while Figure 2-9 shows an example of the current fields in the Adriatic Sea. 

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Figure 2-8 MFS Mediterranean model domain and example of temperature distribution in 

the whole basin. Source: the image is extracted from the GNOO (Gruppo 

Nazionale di Oceanografia Operativa) website, 

http://gnoo.bo.ingv.it/mfs/web_ita/contents.htm. 

Figure 2-9 Example of MFS current fields for the Adriatic Sea. Source: the image is 

extracted from the GNOO (Gruppo Nazionale di Oceanografia Operativa) 

website, http://gnoo.bo.ingv.it/mfs/web_ita/contents.htm. 

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MFS data are available under MyOcean project [3] since 01/01/2006 (to date) 

and have been extracted for the model point of coordinates LON 19.25°, LAT 

40.75°, located about 10 km offshore of the Albanian landfall site. 

The location of the MSF point is illustrated in Figure 2-10. 

The sea temperature and salinity data, at surface, 10 m and 20 m depth, have 

been processed and illustrated as yearly time series, for every year from 2006 to 

2011, in Appendix A for temperature and in Appendix B for salinity. 

The current fields (as current speed and current mean direction), at surface, 10 

m and 20 m depth, have been processed and illustrated as monthly time series, 

for every year from 2006 to 2011, in Appendix C. 

Figure 2-10 Location of the Albanian MFS point. Source: Google Earth. 

2.4.1 Currents, temperature and salinity offshore the Albanian landfall site 

In the below plots the current fields, at surface, 10 m and 20 m depth, as yearly 

current roses (Figure 2-11 and Figure 2-12) and seasonal current roses (Figure 

2-13, Figure 2-14, Figure 2-15) are illustrated. 

From the analysis of the surface current rose, a bimodal trend appears; in fact 

the strongest and most frequent currents come from north-east and from southsouth-west 

(maximum current speed about 0.5 m/s). 

The current rose at 10 m depth shows a similar trend characterized by the 

strongest and most frequent currents from north-east and from south-west. But 

in this case the north-east sector of incoming currents is narrower and turned 

towards north. In addition, the current speed at 10 m depth appears a lot 

weaker than at surface. 

The current rose at 20 m depth looks similar to the rose at 10 m depth but the 

currents are even weaker. 

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From the analysis of these roses, it can be concluded that a significant 

stratification of the currents is present offshore the Albanian landfall site. 

Figure 2-11 Surface yearly current rose generated using MyOcean Products [3]. Source: 

the rose is processed by DHI on the basis of the oceanographic data 

downloaded from MyOcean website (http://www.myocean.org/) for the point 

of coordinates LON 19.25°, LAT 40.75° for the period 01/01/2006- 

01/11/2011 

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Figure 2-12 10 m (left) and 20 m (right) water depth current roses generated using 

MyOcean Products [3]. Source: the roses are processed by DHI on the basis 

of the oceanographic data downloaded from MyOcean website 

(http://www.myocean.org/) for the point of coordinates LON 19.25°, LAT 

40.75° for the period 01/01/2006-01/11/2011 

The seasonal analysis (at surface, 10 m and 20 m depth) confirms the yearly 

trend and the relevant stratification of the currents. In fact, the current speed at 

20 m depth appears significantly weaker than at surface. 

From the seasonal analysis, it is also possible to observe a different trend during 

the spring/summer months and during the autumn/winter months: in the first 

case the most important sector of incoming currents is north-east; this sector is 

turned more towards north in deeper water. 

During the autumn and winter seasons the current directions show a higher 

variability, characterized by two main sectors: north-east and south-west. In 

autumn/winter, the strongest and most frequent currents come from southsouth-west. 

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Figure 2-13 Surface seasonal current roses generated using MyOcean Products [3]. 

Source: the roses are processed by DHI on the basis of the oceanographic 

data downloaded from MyOcean website (http://www.myocean.org/) for the 

point of coordinates LON 19.25°, LAT 40.75° for the period 01/01/2006- 

01/11/2011 

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Figure 2-14 10 m depth seasonal current roses generated using MyOcean Products [3]. 




01/11/2011 

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Figure 2-15 20 m depth seasonal current roses generated using MyOcean Products [3]. 




01/11/2011 

Together with the currents, also temperature and salinity data coming from the 

MyOcean database [3] have been extracted and processed. 

The analysis of yearly temperature and salinity trends, at surface, 10 m and 20 

m depths is illustrated in Appendix A and B, respectively. 

The minimum temperature during the year is around 13.0°C and it is reached in 

February, while the maximum temperature is around 26.5°C (at surface) and it 

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is reached in July. As an example, the 2010 temperature time series is illustrated 

in Figure 2-16. 

Relevant differences in temperature, around 6°, between surface and 20 m 

depth can be found during summer (when the stratification is higher). Also 

during the winter and autumn months there is a limited stratification, with a 

maximum variation of temperature between surface and 20 m depth around 1°. 

At the Albanian landfall site, an important stratification of the water column also 

in terms of salinity is present (as an example, the 2010 salinity time series is 

illustrated in Figure 2-17): the differences between surface and 20 m depth are 

around 4 PSU (38.8-34.8 PSU). This variability is not only distributed along the 

water column, but also during the year, even if it is not straightforward to define 

a seasonal trend. The salinity variations presumably originated by the proximity 

of two important river mouths (Vjosa and Seman rivers). 

Figure 2-16 Example of yearly sea temperature at three different depths (0, -10, -20 m 

m.s.l.) offshore the Albanian coast. Source: the trends are processed by DHI 

on the basis of the oceanographic data downloaded from MyOcean website 

[3] (http://www.myocean.org/) for the point of coordinates LON 19.25°, LAT 

40.75° for the period 01/01/2010-31/12/2010 

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Figure 2-17 Example of yearly sea salinity at three different depths (0, -10, -20 m m.s.l.) 

offshore the Albanian coast. Source: the trends are processed by DHI on the 

basis of the oceanographic data downloaded from MyOcean website [3] 


40.75° for the period 01/01/2010-31/12/2010 

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3 REPRESENTATIVE METEOMARINE SCENARIOS 

In order to model the representative hydrodynamic conditions characterising the 

area around the pipeline route at the Albanian landfall site, the following three 

different scenarios have been selected. 

The meteomarine forcing which has been considered refers to wind, waves, tide, 

currents from the general circulation of the Adriatic Sea (baroclinic currents), 

temperature and salinity, as illustrated in the previous chapters. Since the 

analysis of offshore data (Chapter 2) pointed out the presence of a seasonal 

trend, two representative scenarios for two different seasonal representative 

behaviours have been selected. In addition, a representative scenario of storm 

conditions has been taken into account. 

1. Scenario 1: Representative meteomarine conditions during autumn/winter 

season. 

This scenario has been selected in order to model the hydrodynamic field due 

to typical meteomarine autumn/winter conditions. A real period of 15 days 

has been considered, so that a complete tidal cycle is included in the 

simulation. 

Scenario 1 conditions will be used to simulate the dispersion of the fine 

sediment which will be released during dredging operations. 

In order to select a reliable and representative scenario for this autumn/winter 

scenario, with reference to the analysis of offshore data illustrated in 

Chapter 2, a time window during which currents come from south-south- 

West and are characterized by speed values with high frequency of 

occurrence has been selected. The vertical stratification of salinity and 

temperature is not relevant in these months. The selected time window is the 

period between 04/01/2008 and 18/01/2008. 

In Table 3-1 the daily averaged values of velocity components, temperature 

and salinity at 10 reference depths for the 15-day period are illustrated 

(source: MyOcean database [3]). 

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Table 3-1 

Temperature (T), salinity (S), horizontal (U) and vertical (V) current velocity 

components at 10 different reference depths during the 15 days of the 

autumn/winter scenario. Source: oceanographic data downloaded from 

MyOcean website [3] (http://www.myocean.org/) for the point of coordinates 

LON 19.25°, LAT 40.75° for the period 04/01/2008-18/01/2008 

Depth [m] 

1 5 8 12 15 20 24 29 34 40 

04/01/2008 

05/01/2008 

06/01/2008 

07/01/2008 

08/01/2008 

09/01/2008 

10/01/2008 

11/01/2008 

12/01/2008 

13/01 

/2008 

T [°C] 13.8 14.2 14.7 15.1 15.3 15.3 15.3 15.3 15.2 15.2 

S [PSU] 37.6 37.8 38.1 38.3 38.4 38.5 38.5 38.5 38.5 38.5 

U [m/s] -0.026 -0.024 -0.001 0.005 -0.002 -0.003 -0.002 0.000 0.005 0.004 

V [m/s] 0.124 0.064 0.002 -0.017 -0.018 -0.002 0.001 0.001 -0.001 -0.001 

T [°C] 14.2 14.2 14.3 14.4 14.6 14.8 15.0 15.2 15.3 15.3 

S [PSU] 37.8 37.8 37.8 37.9 38.1 38.2 38.3 38.4 38.5 38.5 

U [m/s] 0.061 0.062 0.066 0.067 0.053 0.019 -0.003 -0.027 -0.044 -0.046 

V [m/s] 0.367 0.350 0.293 0.200 0.129 0.080 0.048 0.027 0.022 0.018 

T [°C] 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.1 15.2 

S [PSU] 38.3 38.3 38.3 38.3 38.3 38.3 38.3 38.3 38.4 38.4 

U [m/s] 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.021 0.003 

V [m/s] 0.381 0.381 0.381 0.372 0.331 0.229 0.145 0.099 0.071 0.025 

T [°C] 15.0 15.0 15.0 15.0 15.0 15.1 15.1 15.1 15.1 15.1 

S [PSU] 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 38.4 

U [m/s] 0.010 0.010 0.010 0.010 0.010 0.010 0.010 0.010 0.010 0.010 

V [m/s] 0.126 0.126 0.126 0.125 0.096 0.056 0.033 0.017 0.011 0.011 

T [°C] 14.7 14.9 15.0 15.0 15.1 15.1 15.1 15.1 15.1 15.1 

S [PSU] 37.8 38.1 38.3 38.3 38.4 38.4 38.4 38.4 38.4 38.4 

U [m/s] 0.001 0.001 0.004 -0.001 -0.009 -0.008 0.001 0.001 0.001 0.001 

V [m/s] 0.105 0.047 0.022 0.013 0.006 -0.003 -0.001 -0.001 -0.001 -0.001 

T [°C] 14.2 14.8 15.0 15.1 15.1 15.1 15.1 15.1 15.1 15.1 

S [PSU] 36.8 37.9 38.3 38.3 38.4 38.4 38.5 38.5 38.5 38.5 

U [m/s] -0.056 -0.002 0.003 -0.003 -0.003 0.000 0.003 0.006 0.012 0.013 

V [m/s] 0.092 0.035 0.000 -0.007 -0.013 -0.006 -0.006 -0.007 -0.008 -0.008 

T [°C] 13.9 14.7 15.0 15.1 15.1 15.1 15.1 15.1 15.1 15.1 

S [PSU] 36.1 37.7 38.2 38.3 38.4 38.5 38.5 38.5 38.5 38.5 

U [m/s] -0.016 0.013 -0.003 -0.007 -0.008 -0.001 0.002 0.005 0.012 0.012 

V [m/s] 0.061 0.002 -0.008 -0.011 -0.021 -0.011 -0.008 -0.009 -0.010 -0.010 

T [°C] 13.8 14.6 15.0 15.1 15.2 15.1 15.1 15.1 15.1 15.1 

S [PSU] 35.9 37.4 38.2 38.3 38.4 38.5 38.5 38.5 38.5 38.5 

U [m/s] 0.009 0.013 -0.008 -0.013 -0.015 -0.006 -0.002 0.001 0.010 0.011 

V [m/s] 0.089 0.006 -0.014 -0.014 -0.025 -0.017 -0.012 -0.012 -0.014 -0.013 

T [°C] 14.2 14.3 14.7 15.0 15.2 15.2 15.2 15.2 15.1 15.1 

S [PSU] 36.9 37.2 37.6 38.1 38.3 38.4 38.5 38.5 38.5 38.5 

U [m/s] 0.093 0.088 0.056 0.025 -0.001 -0.015 -0.020 -0.020 -0.015 -0.015 

V [m/s] 0.323 0.217 0.125 0.067 0.044 0.005 0.001 0.001 0.000 0.000 

T [°C] 14.8 14.8 14.8 14.8 14.9 15.0 15.1 15.1 15.1 15.1 

S [PSU] 38.1 38.1 38.1 38.1 38.2 38.3 38.4 38.5 38.5 38.5 

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Depth [m] 

1 5 8 12 15 20 24 29 34 40 

U [m/s] 0.043 0.043 0.043 0.043 0.043 0.036 0.018 0.006 -0.001 -0.008 

V [m/s] 0.421 0.419 0.391 0.287 0.191 0.107 0.038 0.005 0.005 0.001 

18/01/2008 17/01/2008 16/01/2008 15/01/2008 14/01/2008 

T [°C] 14.8 14.8 14.8 14.8 14.8 14.8 14.9 14.9 15.0 15.0 

S [PSU] 38.3 38.3 38.3 38.3 38.3 38.4 38.4 38.4 38.5 38.5 

U [m/s] 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 

V [m/s] 0.261 0.261 0.261 0.259 0.199 0.134 0.080 0.027 0.000 -0.002 

T [°C] 14.5 14.6 14.7 14.7 14.8 14.8 14.9 14.9 14.9 14.9 

S [PSU] 38.1 38.2 38.3 38.3 38.3 38.4 38.4 38.5 38.5 38.5 

U [m/s] 0.001 0.001 0.001 0.001 0.001 0.002 0.003 0.003 0.003 0.003 

V [m/s] 0.074 0.047 0.036 0.028 0.008 -0.005 -0.003 -0.004 -0.004 -0.004 

T [°C] 14.3 14.4 14.6 14.7 14.7 14.8 14.8 14.9 14.9 14.9 

S [PSU] 37.9 37.9 38.1 38.2 38.3 38.4 38.5 38.5 38.5 38.5 

U [m/s] 0.035 0.035 0.035 0.035 0.025 0.011 -0.005 -0.018 -0.019 -0.020 

V [m/s] 0.310 0.214 0.130 0.077 0.044 0.007 0.002 0.001 0.001 0.001 

T [°C] 14.6 14.6 14.6 14.6 14.7 14.7 14.8 14.8 14.8 14.8 

S [PSU] 38.2 38.2 38.2 38.2 38.3 38.3 38.4 38.5 38.5 38.5 

U [m/s] 0.033 0.033 0.033 0.033 0.033 0.033 0.030 0.024 0.022 0.021 

V [m/s] 0.424 0.417 0.386 0.288 0.192 0.102 0.028 -0.001 -0.003 -0.003 

T [°C] 14.6 14.6 14.6 14.6 14.6 14.7 14.7 14.8 14.8 14.8 

S [PSU] 38.3 38.3 38.3 38.3 38.3 38.4 38.4 38.5 38.5 38.5 

U [m/s] 0.016 0.016 0.016 0.016 0.016 0.016 0.015 0.014 0.015 0.015 

V [m/s] 0.273 0.273 0.271 0.215 0.150 0.089 0.036 -0.003 -0.007 -0.007 

In addition to temperature, salinity and currents from the general circulation 

of the Adriatic Sea (baroclinic currents), also wind conditions for the selected 

time window have been extracted. As illustrated in Chapter 2, the WATCH 

model database has been used [2]. In particular, the hourly values of wind 

velocity components U and V, together with the hourly atmospheric pressure 

for the period 04/01/2008 – 18/01/2008, have been extracted from the 

closest location (the closest cell) to the Albanian landfall site. 

Finally, the astronomical tide conditions at the site during the period 

04/01/2008 – 18/01/2008 have been extracted from C-MAP database [5] 

(Chapter 2); the time series for the 15 days is illustrated in Figure 3-1: an 

entire tidal cycle is represented. 

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Figure 3-1 Astronomical tide during the period 04/01/2008 – 18/01/2008 for the Durres 

C-MAP station. Source: The time series is extracted from the database 

available in the tool MIKE C-MAP, part of DHI software package [5], station: 

Durres, period: 04/01/2008 – 18/01/2008 

2. Scenario 2: Representative meteomarine conditions during spring/summer 

season. 

This scenario has been selected in order to model the hydrodynamic field due 

to typical meteomarine spring/summer conditions. Again, a real period of 15 

days has been considered, so that a complete tidal cycle is included in the 

simulation. 

Scenario 2 conditions will be used in order to simulate the dispersion of the 

fine sediment which will be released during dredging operations. 

In order to select a reliable and representative scenario for this spring/summer 

scenario, with reference to the analysis of offshore data illustrated in 

Chapter 2, a time window during which currents come from north-east and 

are characterized by speed values with high frequency of occurrence has 

been selected (lower average speed than scenario 1). The vertical 

stratification of salinity and temperature is significant in these months, with a 

difference between surface and 20 m depth of around 8°C for temperature 

and of around 1 PSU for salinity. The selected time window is the period 

between 23/06/2008 and 07/07/2008. 

In Table 3-2 the daily averaged values of velocity components, temperature 

and salinity at 10 reference depths for the 15-day period are illustrated 

(source: MyOcean database [3]). 

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Table 3-2 

Temperature (T), salinity (S), horizontal (U) and vertical (V) current velocity 

at 10 different reference depths during the 15 days. Source: oceanographic 

data downloaded from MyOcean website [3] (http://www.myocean.org/) for 

the point of coordinates LON 19.25°, LAT 40.75° for the period 23/06/2008- 

07/07/2008 

Depth [m] 

1 5 8 12 15 20 24 29 34 40 

30/06/2008 29/06/2008 28/06/2008 27/06/2008 26/06/2008 25/06/2008 24/06/2008 23/06/2008 

T [°C] 23.6 22.6 21.8 20.7 19.1 17.2 16.3 15.7 15.4 15.3 

S [PSU] 37.7 37.9 38.0 38.1 38.2 38.3 38.3 38.4 38.4 38.4 

U [m/s] -0.076 -0.040 -0.028 -0.026 -0.033 -0.004 0.001 -0.001 0.009 0.015 

V [m/s] -0.213 -0.161 -0.150 -0.124 -0.138 -0.061 -0.032 -0.020 -0.016 -0.016 

T [°C] 23.9 22.6 21.6 20.4 18.8 17.1 16.3 15.6 15.3 15.2 

S [PSU] 37.8 38.0 38.1 38.1 38.2 38.3 38.3 38.4 38.4 38.4 

U [m/s] -0.097 -0.048 -0.028 -0.018 -0.025 -0.001 0.003 0.002 0.010 0.016 

V [m/s] -0.221 -0.156 -0.145 -0.121 -0.132 -0.057 -0.030 -0.019 -0.015 -0.015 

T [°C] 24.1 22.4 21.3 20.1 18.6 17.0 16.2 15.6 15.3 15.2 

S [PSU] 37.8 38.0 38.1 38.2 38.2 38.3 38.3 38.4 38.4 38.4 

U [m/s] -0.093 -0.042 -0.023 -0.017 -0.027 -0.003 0.001 -0.001 0.009 0.016 

V [m/s] -0.233 -0.163 -0.151 -0.128 -0.138 -0.061 -0.032 -0.021 -0.017 -0.017 

T [°C] 24.4 22.3 21.1 19.8 18.3 16.8 16.1 15.5 15.2 15.2 

S [PSU] 37.9 38.1 38.1 38.2 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.091 -0.040 -0.027 -0.024 -0.033 -0.006 0.001 0.000 0.012 0.018 

V [m/s] -0.215 -0.169 -0.157 -0.129 -0.136 -0.062 -0.035 -0.025 -0.022 -0.022 

T [°C] 24.9 22.6 21.1 19.8 18.5 17.0 16.1 15.5 15.2 15.1 

S [PSU] 37.9 38.1 38.1 38.2 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.033 -0.025 -0.024 -0.021 -0.029 -0.009 -0.003 -0.007 0.002 0.008 

V [m/s] -0.158 -0.150 -0.129 -0.099 -0.107 -0.052 -0.029 -0.018 -0.014 -0.014 

T [°C] 25.2 22.7 21.0 19.7 18.5 17.1 16.2 15.6 15.2 15.2 

S [PSU] 37.8 38.1 38.2 38.2 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.075 -0.026 -0.019 -0.014 -0.019 -0.003 0.001 -0.001 0.005 0.010 

V [m/s] -0.159 -0.132 -0.116 -0.092 -0.097 -0.045 -0.024 -0.015 -0.011 -0.011 

T [°C] 24.8 22.3 20.8 19.5 18.3 17.0 16.2 15.6 15.2 15.2 

S [PSU] 37.8 38.1 38.2 38.2 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.104 -0.029 -0.014 -0.010 -0.015 0.001 0.003 0.001 0.004 0.008 

V [m/s] -0.182 -0.124 -0.109 -0.084 -0.088 -0.034 -0.017 -0.010 -0.006 -0.006 

T [°C] 24.4 22.0 20.5 19.3 18.2 16.9 16.3 15.7 15.3 15.2 

S [PSU] 37.8 38.1 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.076 -0.031 -0.014 -0.012 -0.014 0.001 0.003 0.001 0.001 0.004 

V [m/s] -0.183 -0.119 -0.097 -0.072 -0.074 -0.026 -0.012 -0.006 -0.003 -0.003 

01/0 

7/20 

08 

T [°C] 24.7 22.1 20.5 19.4 18.3 17.1 16.4 15.8 15.3 15.3 

S [PSU] 37.8 38.0 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

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Depth [m] 

1 5 8 12 15 20 24 29 34 40 

U [m/s] -0.058 -0.028 -0.013 -0.007 -0.006 0.004 0.005 0.003 0.000 0.001 

V [m/s] -0.159 -0.107 -0.076 -0.049 -0.048 -0.016 -0.006 -0.002 0.002 0.001 

07/07/2008 06/07/2008 05/07/2008 04/07/2008 03/07/2008 02/07/2008 

T [°C] 24.9 22.1 20.4 19.3 18.3 17.1 16.5 15.9 15.4 15.3 

S [PSU] 37.7 38.0 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.041 -0.025 -0.015 -0.006 -0.004 0.005 0.006 0.005 0.001 0.001 

V [m/s] -0.115 -0.084 -0.062 -0.042 -0.040 -0.011 -0.002 0.001 0.004 0.003 

T [°C] 25.0 22.1 20.3 19.2 18.2 17.1 16.5 16.0 15.5 15.4 

S [PSU] 37.5 38.0 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.064 -0.019 -0.010 -0.007 -0.005 0.005 0.006 0.006 0.003 0.004 

V [m/s] -0.143 -0.084 -0.062 -0.044 -0.044 -0.009 -0.002 0.000 0.002 0.001 

T [°C] 25.1 22.1 20.4 19.3 18.2 17.1 16.5 16.0 15.6 15.5 

S [PSU] 37.5 37.9 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.040 -0.018 -0.012 -0.009 -0.008 0.004 0.005 0.004 0.002 0.003 

V [m/s] -0.125 -0.095 -0.066 -0.041 -0.042 -0.010 -0.001 0.002 0.003 0.002 

T [°C] 25.4 22.4 20.4 19.2 18.3 17.2 16.5 16.1 15.6 15.5 

S [PSU] 37.4 37.9 38.2 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.025 -0.030 -0.022 -0.011 -0.004 0.007 0.009 0.009 0.005 0.005 

V [m/s] -0.074 -0.076 -0.048 -0.027 -0.027 -0.005 0.000 0.003 0.004 0.003 

T [°C] 25.7 22.9 20.5 19.2 18.3 17.2 16.6 16.2 15.7 15.6 

S [PSU] 37.3 37.8 38.1 38.3 38.3 38.3 38.4 38.4 38.4 38.4 

U [m/s] -0.048 -0.024 -0.005 0.000 0.002 0.006 0.006 0.006 0.002 0.001 

V [m/s] -0.098 -0.052 -0.041 -0.030 -0.028 -0.004 0.003 0.005 0.006 0.006 

T [°C] 25.2 22.4 20.3 19.1 18.1 17.0 16.5 16.1 15.7 15.6 

S [PSU] 37.3 37.8 38.2 38.3 38.3 38.4 38.4 38.4 38.4 38.4 

U [m/s] -0.058 -0.017 -0.015 -0.014 -0.012 0.004 0.007 0.008 0.008 0.010 

V [m/s] -0.133 -0.093 -0.064 -0.041 -0.043 -0.007 0.000 0.002 0.002 0.001 

As illustrated for scenario 1, in addition to temperature, salinity and currents 

from the general circulation of the Adriatic Sea (baroclinic currents), also 

wind conditions for the selected time window have been extracted. As 

illustrated in Chapter 2, the WATCH model database has been used [2]. In 

particular, the hourly values of wind velocity components U and V, together 

with the hourly atmospheric pressure for the period 23/06/2008 – 

07/07/2008, have been extracted from the closest location (the closest cell) 

to the Albanian landfall site. 

Finally, the astronomical tide conditions at the Albanian landfall site during 

the period 23/06/2008 – 07/07/2008 have been extracted from C-MAP 

database (Chapter 2) [5]; the time series for 15 days is illustrated in Figure 

3-2: an entire tidal cycle is represented. 

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Figure 3-2 Astronomical tide during the period 23/06/2008 – 07/07/2008 for the Durres 

C-MAP station. Source: The time series is extracted from the database 

available in the tool MIKE C-MAP, part of DHI software package [5], station: 

Durres, period: 23/06/2008 – 07/07/2008 

3. Scenario 3: Representative meteomarine conditions for a spring/summer 

storm event. 

In this scenario the same meteomarine conditions assumed for scenario 2 of 

tide, wind and currents from the general circulation of the Adriatic Sea 

(baroclinic currents), have been considered. In addition, a relatively severe 

wave event has been added. 

Scenario 3 therefore includes the effect of wave generated currents and since 

the dredging operations will be suspended during storm conditions, this 

scenario will be particularly relevant in terms of resuspension of the amount 

of dredged sediment which will be temporarily deposited close to the dredged 

channel during the operations. The assumption for scenario 3 is that dredging 

operations will likely take place in the spring/summer period, which is 

characterized by a lower frequency and magnitude of storms. 

Under assumed wave conditions, a storm event characterized by a simplified 

triangular shape has been considered (Figure 3-3). The significant wave 

height at the peak of the storm has been chosen referring to the scatter 

analysis illustrated in Table 2-5 and Table 2-4 for spring/summer seasons: 

the most frequent direction for the seasons and a wave height characterized 

by approximately one year’s return period have been selected. 

The peak wave period has been estimated referring to the bivariate statistics 

provided by “Wind and Wave Mediterranean Atlas” [1] (Table 2-7). The wave 

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height at the peak of the storm, together with the mean wave direction and 

the peak wave period are illustrated in Table 3-3. 

Table 3-3 

Significant wave height, mean wave direction and peak wave period at the 

peak of the storm 

H s [m] T p [s] MWD [°N] 

2.5 7.0 315 

Figure 3-3 Modification of significant wave height during the storm event: shape of 

triangular wave storm assumed for scenario 3 

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4 3D HYDRODYNAMIC MODEL 

The numerical modelling study has been performed using the MIKEbyDHI 

package, developed by DHI (Danish Hydraulic Institute). In particular, the 3D 

model MIKE 3 HD FM has been used for the simulation of hydrodynamic fields in 

the Albanian landfall site. 

The MIKE 3 primitive equation model is based on a flexible mesh approach and it 

has been developed for applications within oceanographic, coastal and estuarine 

environments. The spatial discretization of the equations is performed using a 

cell centred finite volume method. 

The horizontal discretization can combine triangles and quadrilateral elements, 

while the vertical is based on a sigma or combined sigma-zed discretization. 

Together with the inclusion of the Flather boundary conditions, the model is ideal 

for down scaling the regional scale oceanographic models to high resolution 

coastal application. The regional scale resolution and bathymetry can be very 

well approximated at the boundaries, then gradually imposing the higher 

resolution through the flexible mesh approach. 

A detailed description of MIKE 3 HD FM model is included in Appendix F. 

In Section 4.1, a detailed description of the bathymetric data used in the model, 

together with a description of the model domain and the adopted horizontal and 

vertical resolution are illustrated. In Sections 4.2 to 4.4 the results of the 

hydrodynamic model for the three scenarios are illustrated, while some 

considerations on tidal currents can be found in Section 4.5. 

It has to be noticed that the model is not calibrated against measurements, due 

to unavailability of registered data. 

4.1 Bathymetric data, model domain and resolution 

For the bathymetric characterisation of the area, the database CM-93 from C- 

MAP has been used [4]. CM-93 is a global database of nautical cartography in 

digital format, created and continuously updated by the Norwegian C-MAP. 

While nautical charts data are widely used offshore, near shore, in shallow water, 

it is advisable to use a more detailed bathymetric survey, especially where the 

detail of the nautical charts is poor, as in the present case. Figure 4-1 illustrates 

the coarse resolution of nautical charts available for the Albanian landfall site. 

A rough representation of near shore bathymetry could become a critical issue 

when it is needed to model the hydrodynamic conditions at a certain site, 

especially when the modelled currents are generated by waves. In fact, the ratio 

between wave height and water depth is crucial for a proper representation of 

the energy dissipation, which occurs during the propagation of the wave from 

offshore to near shore. 

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Figure 4-1 Bathymetric data extracted from the CM-93 database [4], available within 

MIKE C-MAP toolbox, part of DHI software package [5] 

In order to obtain a more accurate representation of the local bathymetry, a 

detailed bathymetric survey, provided by TAP, has been used. This survey is 

showed in Annex D of the document “OPL00-STA-160-Y-TAE-0001_00-Final 

Report Environmental Survey Albanian Landfall”, where the environmental chart 

for the east side is represented. This detailed bathymetry is available for a 

narrow corridor (Figure 4-2) along the pipeline route, so these data have been 

merged with the bathymetric data coming from the C-MAP database [5] (Figure 

4-3). 

Latitude [°] 

Latitude [°] 

Longitude [°] 


Figure 4-2 Bathymetric survey provided by TAP 

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Latitude [°] 


Figure 4-3 Merge of the two sources of bathymetric data: bathymetric survey provided 

by TAP and bathymetric data extracted from CM-93 database [4] 

The final result of this processing is illustrated in Figure 4-4 where the model 

bathymetry is illustrated, including lines at equal depth and labels. 

The extension of the model domain is approximately equal to 27,000 m along 

the coast and to 15,000 m in the direction perpendicular to the coast. The 

maximum depth which can be found in the model domain is approximately equal 

to 95 m. 

The model bathymetry has been constructed using the flexible mesh approach: 

the offshore spatial resolution (average length of triangles sides) is around 1,000 

m; gradually, while approaching the coast and to the pipeline route corridor, the 

resolution is finer, up to around 100 m. Along the pipeline route corridor, a 

resolution of around 50 m has been selected; in this corridor a quadrangular 

mesh, instead of triangular, is used (Figure 4-5). The quadrangular mesh is 

more suitable when simulating local sources of sediment, like in this case. 

The vertical discretization is made of 5 sigma-layers combined with one zedlayer. 

The water depth between surface and -20 m is discretized through 5 

sigma-layers, each one characterized by a variable thickness depending on the 

local water depth (i.e. when the water depth is 15 m, the thickness of each 

sigma-layer is 3 m), while the deeper part of the water column is discretized 

through an unique zed-layer. 

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Latitude [°] 


Figure 4-4 Merged bathymetry in the calculation grid used to study the Albanian landfall 

site 

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Latitude [°] 


Figure 4-5 

Mesh used in the numerical model to study the Albanian landfall site 

Following the assumed progress of dredging operation, four different 

bathymetries have been created (Section 5.1.3), each one specific for the 

simulation of the sediment release at a certain point along the pipeline route. 

The detailed description of the dredging phases and the related bathymetries are 

illustrated in Chapter 5. 

4.2 Scenario 1: results 

Scenario 1 is representative of typical autumn/winter conditions. In these 

months the currents from the general circulation of the Adriatic Sea (baroclinic 

currents) are frequently directed from south to north and this direction can be 

found almost constant both along the 15 days simulated and along the water 

column, due to the reduced stratification. 

In general, results show that the currents are stronger offshore than near shore. 

In fact, the general circulation is dominated by currents from the general 

circulation of the Adriatic Sea (baroclinic currents), which are stronger at higher 

depths, because of the lower interaction with the sea bed that causes energy 

dissipation and a reduction in the current speed. 

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Another important forcing that plays an important role in the generation of the 

current field is the wind, the influence of which is very important at the surface. 

The following figures illustrate an example of the hydrodynamic field at three 

different depths (surface, intermediate depth and sea bed depth) for the existing 

bathymetry. The plots corresponding to “surface” and “intermediate depth” are 

referred to the upper and intermediate sigma layer of the model, respectively. 

This means that the plots are not representative of the same depth everywhere: 

where the water depth is 20 m or higher, the intermediate depth is 10 m, where 

the water depth is shallower than 20 m, the intermediate depth is half of the 

local water depth. The plots corresponding to “sea bed depth” are referred to the 

deeper sigma layer. This means that the plot is representative of what happens 

at the sea bed where the water depth is equal or shallower than 20 m (which is 

the limit of the sigma layer – zed layer interface). Where the water depth is 

deeper, the plot is representative of the behavior of the currents at the interface 

depth (20 m). 

The plots refer to two time steps: one is representative of an average condition 

of current speed and direction (04/01/2008), and the other is representative of a 

condition characterized by higher current speed (13/01/2008). The plots 

referring to the same time steps but to different bathymetries are illustrated in 

Appendix D. 

In general, at surface the average current speed is around 0.25 m/s (Figure 4-6) 

and decreases gradually in the deeper layer, up to an average speed of around 

0.1 m/s at the sea bed depth (Figure 4-8). 

The maximum current speed reached during the 15 days of simulation is 

approximately equal to 0.5 m/s at surface (Figure 4-9). At the same time step, 

the maximum current speed at the sea bed depth is around 0.30 m/s (Figure 

4-11). 

The influence of the dredging of the access channel on the hydrodynamic field is 

limited to the area where the channel will be dredged. In particular, the presence 

of the channel creates a discontinuity in the current field: along the dredged 

stretch the current velocity decreases significantly. In general, the current speed 

inside the channel is never higher than 0.05-0.10 m/s. 

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Latitude [°] 


Figure 4-6 Hydrodynamic field at surface for the Albanian landfall site (existing 

bathymetry) during autumn/winter representative conditions (04/01/2008) 

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Latitude [°] 


Figure 4-7 Hydrodynamic field at intermediate depth for the Albanian landfall site 

(existing bathymetry) during autumn/winter representative conditions 

(04/01/2008) 

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Latitude [°] 


Figure 4-8 Hydrodynamic field at sea bed depth for the Albanian landfall site (existing 


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Latitude [°] 




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Latitude [°] 



(existing bathymetry) during autumn/winter representative conditions 

(13/01/2008) 

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Latitude [°] 





Scenario 2 is representative of typical spring/summer conditions. In these 

months the currents from the general circulation of the Adriatic Sea (baroclinic 

currents) are frequently directed from north to south and this direction can be 

found almost constant both along the 15 days simulated but, due to the 

significant stratification of the water column, some differences in the 

hydrodynamic field can be noticed along the water column. 

In general, similarly to scenario 1, the results show that the currents are 

stronger offshore than near shore. 

The following figures illustrate an example of the hydrodynamic field at three 

different depths (surface, intermediate depth and sea bed depth) for the existing 

bathymetry. The definition of “surface”, “intermediate depth” and “sea bed 

depth” is illustrated in section 4.2. The plots refer to two time steps: one is 

representative of an average condition of current speed and direction 

(23/06/2008), and the other (01/07/2008) is representative of a condition 

characterized by the presence of a big eddy which generates at the lee side of the 

Seman river mouth: on this day, in fact, the near shore current is directed from 

south to north. 

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The plots referring to the same time steps but to different bathymetries are 

illustrated in Appendix D. 

In general, at surface the average current speed is around 0.20 m/s (Figure 

4-12) and decreases gradually in the deeper layer, up to an average speed of 

around 0.05 m/s at the sea bed depth (Figure 4-14). 

The maximum current speed reached during the 15 days of simulation is 

approximately equal to 0.40 m/s at surface. At the same time step, the 

maximum current speed at the sea bed depth is around 0.30 m/s. 

For scenario 2 conditions, the influence of the dredging of the access channel on 

the hydrodynamic field is even lower than for scenario 1. The current speed is in 

fact already very weak along the pipeline route, due to the protection from these 

currents induced by the presence of the Seman river mouth shape immediately 

north of the Albanian landfall site. 

Latitude [°] 



bathymetry) during spring/summer representative conditions (23/06/2008) 

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Latitude [°] 



(existing bathymetry) during spring/summer representative conditions 

(23/06/2008) 

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Latitude [°] 




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Latitude [°] 




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Latitude [°] 



(existing bathymetry) during spring/summer representative conditions 

(01/07/2008) 

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Latitude [°] 





In this scenario the same meteomarine conditions assumed for scenario 2 of 

tide, wind and currents from the general circulation of the Adriatic Sea 

(baroclinic currents) have been considered. In addition, a relatively severe wave 

event characterized by a duration of 48 h has been added. 

Scenario 3 therefore includes the effect of wave generated currents: during the 

propagation of the waves from offshore to near shore, when approaching the so 

called surf zone, if the mean wave direction is not perpendicular to the isolines, a 

gradient in radiation stress fields at the seabed generates longshore currents, 

which are characterized by higher speed in case of large waves and very oblique 

wave attack. 

In general, longshore currents are not strong enough to lift the sediment from 

the seabed and disperse it in the water column: the main responsible for this is 

the mechanical action of wave breaking, while longshore currents are responsible 

for the horizontal movement of the suspended sediments once they have already 

been put in suspension. 

On the basis of the above, a significant amount of sediment can be put in 

suspension from wave breaking, which mainly occurs in shallow water. The 

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presence of the temporary amount of sediment nearby the dredged channel 

locally determines shallow water conditions, above which wave breaking can 

therefore dissipate a great part of the energy associated to the incident wave. 

This is the reason why, for Scenario 3, the temporary amount of sediment is 

included in the model bathymetry. 

From the analysis of the model results, higher values of current speed can be 

observed where the temporary deposit will be placed (shallow water, more 

severe wave breaking). On the contrary, inside the channel, due to the local 

deepening of the seabed, the current speed decreases. This situation is 

particularly evident in Figure 4-20, Figure 4-21, and Figure 4-22. 

For this scenario, results have been plotted at three different depths (surface, 

intermediate depth and sea bed depth) in four different time steps. The time 

steps considered as representatives of this scenario are the following: 

 

 

 

growing phase of the storm: it is the first time step at which the significant 

wave height is bigger than 1.0 m (23/06/2008 – h. 7.00); 

peak of the storm: the wave event reaches the maximum significant wave 

height, which is equal to 2.5 m (23/06/2008 – h. 16.00); 

decreasing phase of the storm: it is the first time step at which the significant 

wave height again becomes smaller than 1.0 m (24/06/2008 – h. 11.00). 

During the growing phase of the storm, when the current speed is still low, at 

surface, in the zone of the channel the current speed is around 0.1 m/s and 

around 0.3 m/s in the zone of the deposit (Figure 4-12), while it is respectively 

0.05 m/s and 0.15 m/s in the deeper layer (Figure 4-14). 

At the peak of the storm, the current speed at surface is around 0.25 m/s inside 

the channel and higher than 0.50 m/s above the sediment deposit and around 

the dredged channel in general (Figure 4-21). At deeper water, the current 

speed is around 0.10 m/s along the channel and around 0.30 m/s above the 

temporary deposit. 

Again, the definition of “surface”, “intermediate depth” and 

associated to each plot is illustrated in section 4.2. 

“sea bed depth” 

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Latitude [°] 


Figure 4-18 Hydrodynamic field at surface for the Albanian landfall site (bathymetry 

includes the temporary deposit of dredged sediment) during the growing 

phase of the storm, at the first time step at which the significant wave height 

is bigger than 1.0 m (23/06/2008 – h. 7.00) 

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Latitude [°] 



(bathymetry includes the temporary deposit of dredged sediment) during the 

growing phase of the storm, at the first time step at which the significant 

wave height is bigger than 1.0 m (23/06/2008 – h. 7.00) 

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Latitude [°] 


Figure 4-20 Hydrodynamic field at sea bed depth for the Albanian landfall site 




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Latitude [°] 



includes the temporary deposit of dredged sediment) during the peak of the 

storm, when the wave event reaches the maximum significant wave height 

equal to 2.5 m (23/06/2008 – h. 16.00) 

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Latitude [°] 




peak of the storm, when the wave event reaches the maximum significant 

wave height equal to 2.5 m (23/06/2008 – h. 16.00) 

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Latitude [°] 






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Latitude [°] 



includes the temporary deposit of dredged sediment) during the decreasing 


again becomes smaller than 1.0 m (24/06/2008 – h. 11.00) 

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Latitude [°] 




decreasing phase of the storm, at the first time step at which the significant 

wave height again becomes smaller than 1.0 m (24/06/2008 – h. 11.00) 

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Latitude [°] 






4.5 Considerations on tidal currents 

It is important to notice that the contribution of tidal currents in the 

representative current conditions at the Albanian landfall site can be considered 

as negligible: specific simulations considering only tidal forcing have been 

performed and the conclusion is that the current speed induced by tidal variation 

is at least one order of magnitude lower than currents from the general 

circulation of the Adriatic Sea (baroclinic currents) and/or wind currents at 

surface (example in Figure 4-27, where the current field during a condition of 

spring tide is illustrated). This figure shows a maximum current speed of about 

0.016 m/s and an average speed of about 0.01 m/s. 

Although it is negligible, the tidal current contribution is included as a separate 

forcing in both scenario 1 and scenario 2. 

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Latitude [°] 


Figure 4-27 Current field at the Albanian landfall site generated by astronomical tide 

variations (Spring tide condition) 

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5 3D SEDIMENT DISPERSION MODEL 

The numerical modelling study of the sediment dispersion during dredging 

operations and during storm conditions has been performed using the 

MIKEbyDHI package, developed by DHI (Danish Hydraulic Institute). In 

particular, the 3D model MIKE 3 MT FM has been used for the simulation of 

sediment dispersion in the area. 

MT is a specific module developed to simulate the suspension and sedimentation 

of cohesive and mixed sediments under hydrodynamics forcing and external 

actions. 

The mud transport model includes the following physical phenomena: 

 

 

 

 

 

 

flocculation due to concentration; 

flocculation due to salinity; 

density effects at high concentrations; 

hindered settling; 

consolidation; 

morphological bed changes 

A detailed description of MIKE 3 MT FM model [7] is included in Appendix G. 

The sediment dispersion model is fully integrated with the hydrodynamic model 

MIKE 3 HD FM [6] (Chapter 4). Each simulation of the MT model is therefore 

characterized by a duration of 15 days, during which the plume of suspended 

sediment released during dredging operations or during a storm changes in 

extension, shape and concentration according to hydrodynamics (advection) and 

dispersion conditions. 

In Section 5.1 the methodological approach is illustrated, including the selection 

of representative points for the sediment release, the estimation of the dredging, 

release rates and settling velocity and the definition of the model bathymetries. 

In Sections 5.3 to 5.5 the maps of the maximum sediment concentrations over 

the entire duration of the simulation, averaged in the first 20 m of the water 

column and for the selected release points are illustrated. 

The plots representing maps of suspended sediment concentration (SSC) at 

three different depths (surface, intermediate depth and sea bed depth) for 

significant time steps are illustrated in Appendix E. 

5.1 Methodological approach 

5.1.1 Selection of representative points for the sediment release 

The choice of these points has taken into account the different approach in the 

dredging operations at different locations along the pipeline route: three 

different stretches can be identified, as follows: 

 

The first stretch is approximately 200 m long from the shoreline. Along this 

stretch the pipeline is placed through the use of cofferdams. Within the area 

of the cofferdams materials will be removed to a minimum dredging depth of 

3 m; this will provide a minimum burial depth (to top of pipe) of 

approximately 2 m. The purpose of the structure is to prevent natural 

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backfilling and retain the depth of the dredged channel until the pipeline can 

be laid during pipe installation. The area shall remain wet at all times. At this 

first stretch, the sediment released during dredging operations will stay 

confined within the area of the cofferdams. The assumed release point for 

the model of this first stretch is therefore the offshore end of the cofferdams, 

where the sediment can migrate from the protected area to the open sea; 

 

The second stretch is approximately 2,000 m long, from the offshore end of 

the cofferdam, where the depth is around 2.5 m, to a depth of approximately 

8 m. This stretch is characterized by the dredging of an access channel, 

aiming at guaranteeing the accessibility of the dredger to the actual shallow 

water areas. The channel will be dredged using Cutter-Suction Dredger 

(CSD), which excavates the channel by means of cutting and suction, 

pumping the excavated masses through a floating hose controlled by a 

support vessel. The excavated masses will be temporarily deposited outside 

the channel, starting from a distance of around 10 m. The process will be 

reversed when the channel is back-filled following the pipeline installation, 

restoring the seabed to its natural condition. In total the estimated time span 

from beginning of these operations to the end, weather permitting, is 

approximately 80 days: about 40 days are needed to remove the soil from 

the access channel and about 40 days are needed to backfill the same 

channel. In general, the CSD capacity is depending on type and size; 

according to the information provided by TAP, for Albanian landfall a capacity 

of 2,500 m 3 /hour (theoretical 60,000 m 3 per day) has been assumed. The 

access channel will be approximately 160 m wide, 2,000 m long and 5 m 

deep; so the total amount of dredged sediment will be approximately equal 

to 1,600,000 m 3 . 

Along this second stretch, which is the most relevant in terms of released 

quantity of dredged sediment, 4 release points have been considered, each 

representative of different zones and different steps of the operational 

activities. In particular, one point is located at the offshore end of the 

cofferdam (point n°1), one at the offshore end of the access channel (point 

n°4), and the two remaining points (point n°2 and point n°3) are located in 

the middle of the access channel. The mutual distance between the four 

points is constant. The geographical coordinates, the distances from the 

coastline and the water depths where these points are located are illustrated 

in Table 5-1. In addition, the location of the points is illustrated in the plots 

from Figure 5-3 to Figure 5-5. For each of these four points, due to the 

expected dredging methodology, two release sources are considered: one is 

located inside the channel, where the sediment is dredged, and one outside 

the channel, where the material is temporarily deposited. 

Table 5-1 Locationn of release points 

Release 

point 

Geographical coordinates 

[°] 

Depth 

[m] 

Distance 

from the 

coastline [m] 

1 LON 19.3734; LAT 40.7924 2.7 220 

2 LON 19.3655; LAT 40.7921 5.0 880 

3 LON 19.3577; LAT 40.7916 6.7 1,540 

4 LON 19.3500; LAT 40.7911 8.0 2,200 

5 LON 19.3280; LAT 40.7897 11.8 4,000 

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Following the expected time schedule for the dredging operations, each 

release point has been considered representative of 10 days of work: during 

these 10 days, a continuous release is assumed. The simulation time is 

longer (15 days) because there is a time lag between the end of the release 

and the complete dispersion of the suspended sediment introduced in the 

water column. 

 

The third stretch is approximately 4,000 m long, between the offshore end of 

the access channel, where the water depth is 8 m, to a distance from the 

coastline of around 6,000 m, where the water depth is approximately 30 m. 

Along this stretch the pipeline is placed at the bottom of a dredged trench. 

Release point n°5 is located halfway along the trench; the geographical 

coordinates, the distance from the coastline and the water depth of this point 

are illustrated in Table 5-1. In this case, as agreed with TAP, only one release 

source, inside the trench, has been assumed. 

Along this trench the volume of dredged sediment is significantly lower than 

in the access channel. On the basis of the expected time schedule of the 

operations, it has been agreed with TAP that point n°5 is representative of 

only one day of continuous release. 

To study this stretch some assumptions have been made because of the 

uncertainty of operational techniques that will be applied. In particular, it is 

here assumed that the dredging of the offshore stretch will be operated 

through CSD. The use of post-trenching instead of CSD would produce less 

sediment. Hence, the assumption is conservative. 

5.1.2 Dredging rate, release rate, settling velocity 

During dredging operations, both sand fraction and fine fraction are released in 

the water column. The sand fraction is assumed to settle nearby the release 

point and therefore its environmental impact is generally negligible. Following 

the above assumption, the numerical model only aims at simulating the 

dispersion and fate of the fine fraction of the sediment, which can have a 

significant environmental impact since it can remain in suspension for a long 

time and migrate to sensitive areas. 

Under the above assumption, the calculation of the sediment volume that will be 

modelled only refers to the fine fraction of the material. In order to quantify this 

fraction for each of the 5 release points, the grain curves provided by TAP 

referring to the collected samples by FUGRO OCEANSISMICA S.p.A. have been 

used. In particular, the particle size analysis of the samples which are located 

closer to each release point has been considered. Referring to the “Trans Adriatic 

Pipeline (TAP) – Environmental Survey Albanian Landfall – Final Report” provided 

by TAP, for the 5 release points the samples illustrated in Table 5-2 have been 

considered. 

Table 5-2 

Samples used for the sediment dispersion study 

Release point 

number 

Sample 

Sample coordinates 

[°] 

Percentage of fine 

sediment [%] 

1 ADD2 LON 19.37261; LAT 40.7938 13.2 

2 E4 LON 19.3655; LAT 40.7921 8.8 

3 and 4 F4 LON 19.3527; LAT 40.7911 21.2 

5 H4 LON 19.3291; LAT 40.7895 96.2 

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Figure 5-1 illustrates the grain curves associated to the above four sediment 

samples. 

Figure 5-1 Grain curves of the samples listed in Table 5-2 

The grain diameter threshold between sand fraction and fine fraction has been 

assumed equal to 63 μm, according to the Wentworth scale, a standard 

classification for clastic sediment and rock (Figure 5-2). The threshold is the limit 

between very fine sand and coarse silt. 

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Figure 5-2 Wentworth scale for clastic sediment and rock standard classification 

On the basis of the expected dredging rate (2,500 m 3 /hour) and the calculated 

ratio between fine fraction and sand fraction, it has been possible to quantify the 

dredging rate of the fine part of the sediment for each of the 5 points. Based on 

the large DHI experience within dredging studies, a density of 1,900 Kg/m 3 is 

assumed to be reasonable for the fine fraction of sediments. Table 5-3 illustrates 

the dredging rates for the 5 points. 

Table 5-3 

Dredging rates in each release point 

Release point 

number 

Dredging rate 

[m 3 /h] 

Dredging rate 

fine fraction 

[m 3 /h] 

Dredging rate 

fine fraction 

[kg/s] 

1 2,500 330 174 

2 2,500 220 116 

3 2,500 530 280 

4 2,500 530 280 

5 2,500 2,405 1,269 

The high dredging rate for point n°5 (offshore) is due to the high ratio between 

fine fraction and sand fraction. The release from this point is, however, less 

critical because the duration of the release is only 1/10 compared to the other 

points and because the release source is one instead of two (see assumptions in 

Section 5.1.1). 

The amount of sediment actually released in the water column during dredging 

operations is only a fraction of the dredged sediment: the rate of release per unit 

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of dredged material is an "average" loss quantity that can take into account 

differences between dredging methods and enables comparison between 

methods of total mass lost into the surrounding water. Blokland (1988) describes 

a systematic method for determining the quantity of sediment released into the 

immediate vicinity of the dredger, in kg/m 3 dredged. This is the socalled "Sfactor". 

It is based on in situ measurements of suspended sediment 

concentrations, rather than measured release rates from the dredger and so 

takes into account any dynamic plume effects. In this case the S-factor has been 

useful to estimate the magnitude of sediment losses because of the lack of sitespecific 

information of the rate of release per unit of dredged material. 

Kirby and Land (1991) made further use of the S-factor, and provided 

indications on losses of fine sediment resulting from the different types of 

dredging operations in muddy sediment. 

On the basis of the above references and on large DHI experience within 

dredging studies, a release rate of 1% of the dredging rate is assumed to be 

associated to the CSD dredger. 

Another important assumption when modelling sediment dispersion is the 

estimation of settling velocity. In this case, for each release point, 

independently on the grain diameter variations from point to point, a settling 

velocity of 0.05 cm/s has been considered. This estimation is based both on 

DHI’s experience and on many references [8 ÷ 12] regarding the definition of 

settling velocity, which has been estimated to lie between 0.023 and 0.054 cm/s 

for suspended material characterized by diameters smaller than 50 μm. 

5.1.3 Model bathymetries 

As anticipated in Chapter 4, both the hydrodynamic and the mud transport 

model have been setup considering different bathymetric conditions in relation to 

the progress of the dredging operations. A tentative sequence of operations for 

the dredging activities, agreed with TAP, is illustrated below: 

1. Placement of cofferdam: the cofferdam is a simple sheet piling construction 

that extends from the shoreline out to approximately 200 m from the 

shoreline. The purpose of the structure is to prevent natural backfilling and 

retain the depth of the dredged channel until the pipeline can be laid during 

pipe installation; 

2. Dredging of the access channel, from offshore to near shore. The access 

channel is needed in order to allow the CSD (Cutter Suction Dredger) to 

operate in the stretch now characterized by shallow water depths 

(approximately 2,000 m from the end of the cofferdam to offshore). The 

expected width of the channel is 160 m, its average depth is 5 m and the 

total volume dredged is in the order of 1.6 million m 3 ; 

3. Dredging of the trench which will host the pipeline; the trench will be 

dredged from the offshore end of the access channel up to the depth of 25 m 

offshore (approximately length of the trench; 4 km); 

4. Backfilling of the access channel, from onshore to offshore. 

Due to the relevant variations in the bathymetry at different steps of the above 

sequence of operations, four different bathymetries, representing four different 

seabed conditions, have been built: 

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bathymetry n°1 (Figure 5-3): the bathymetry is the existing bathymetry, 

without the presence of the access channel, but with the cofferdam already in 

place. This bathymetry is used to simulate the sediment dispersion for 

release point n°4. This bathymetric representation is used for meteomarine 

scenarios 1 and 2; 

bathymetry n°2 (Figure 5-4): the offshore half of the access channel is 

dredged, the is cofferdam in place. This bathymetry is used to simulate the 

sediment dispersion for release points n°2 and n°3. This bathymetric 

representation is used for meteomarine scenarios 1 and 2; 

bathymetry n°3 (Figure 5-5): the whole access channel is dredged, the 

cofferdam is in place. This bathymetry is used to simulate the sediment 

dispersion for release points n°1 and n°5. This bathymetric representation is 

used for meteomarine scenarios 1 and 2; 

bathymetry n°4 (Figure 5-6): the cofferdam is in place, the whole access 

channel is dredged and the temporary deposit of dredged sediment is in 

place nearby the channel. This bathymetric representation is used for 

meteomarine scenario 3. Due to the high level of uncertainties in assuming a 

reliable shape and location of this deposit, the following assumptions, agreed 

with TAP, are considered: 

o the deposit will be placed very close to the dredged channel 

(starting at a distance of 10 m); 

o the top of the sediment deposit reaches at any location half of the 

actual water depth; 

o as a consequence of the above assumption, the width of the base of 

the sediment deposit is variable along the channel; the width is 

therefore larger where the actual water depth is smaller. If we 

assume this, a sketch for 3 different water depths is illustrated in 

Figure 5-7: at the offshore end of the access channel, where the 

actual water depth is around 8 m, the width of the deposit is 

assumed to be around 200 m, while at the near shore end, next to 

the cofferdam, where the actual water depth is around 3 m, the 

width of the deposit is assumed to be around 530 m. 

As agreed with TAP, due to the high level of uncertainty in assuming a shape and 

location of the temporary deposit, its presence has only been taken into account 

in the simulation of scenario 3, in which the deposit itself is the source of 

sediment resuspension and dispersion. 

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Figure 5-3 Detail of bathymetry n°1 (cofferdam in place, no access channel), used to 

study representative meteomarine scenarios 1 and 2, and location of release 

point n°4 

Latitude [°] 

Latitude [°] 


Figure 5-4 Detail of bathymetry n°2 (cofferdam in place, offshore part half dredged 

within access channel), used to study representative meteomarine scenarios 

1 and 2, and location of release points n°2 and n°3 

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Figure 5-5 Detail of bathymetry n°3 (cofferdam in place, whole access channel 

dredged), used to study representative meteomarine scenarios 1 and 2, and 

location of release points n°1 and n°5 

Latitude [°] 

Latitude [°] 


Figure 5-6 Detail of bathymetry n°4 (cofferdam in place, whole access channel dredged 

and dredged material deposited nearby), used to study representative 

meteomarine scenario 3 

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Figure 5-7 Representation of sea bed after the operations of dredging and deposition 

5.2 Assumptions on background suspended sediment concentration 

The Albanian landfall of the Trans Adriatic Pipeline is located very close to two 

important river mouths: Seman rivers to the north and Vjosa river to the south. 

Considering the relevance of these two rivers and their basins, it has to be 

noticed, although without available data, that there is a high probability that the 

background suspended sediment concentration of the water column in the area, 

which has been assumed equal to zero in the simulations, is naturally high. 


The dispersion and fate of the suspended sediment plume depend essentially on 

the hydrodynamic conditions, once fixed the release location and the release 

rate. 

During the autumn/winter months, considering release point n°1 (Figure 5-8), 

the maximum SSC, averaged in the first 20 m of the water column can be found 

in the cofferdam area, with concentrations that locally, due to the limited water 

depth, can reach 2.5 kg/m 3 . 

Out of the cofferdam area, the SSC rapidly decreases. Significant concentrations 

(higher than 0.1 kg/m 3 ) can still be found between the cofferdam and the Seman 

river mouth (approximately 3 km north of the Albanian landfall site). 

The highest concentration of suspended sediment can be found along the coast, 

distributed over a distance from the shore not higher than 800 ÷ 1,000 m. 

Based on the DHI experience within measurements of suspended sediment 

concentration, 0.002 kg/m 3 can be considered the threshold value below which 

the measured concentration cannot be considered reliable. 

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Latitude [°] 


Figure 5-8 Maximum Suspended Sediment Concentration, averaged in the first 20 m of 

the water column during autumn/winter months for release point n°1 (LON 

19.3734°, LAT 40.7924°) 

Considering release point n°2 (Figure 5-9), the maximum SSC, averaged in the 

first 20 m of the water column, is located between the release point and the 

coastline, with concentrations in the order of 0.20 ÷ 0.30 kg/m 3 . 

Similarly to what happens during the release from point n°1, the highest 

concentration of suspended sediment can be found along the coast, mainly south 

of the area of the cofferdam for 2.5 ÷ 3.0 km. 

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Latitude [°] 



the water column, during autumn/winter months for release point n°2 (LON 

19.3655°, LAT 40.7921°) 


first 20 m of the water column, is located in correspondence to the release 

sources, with values up to 0.65 kg/m 3 . 

In this case, the maximum concentrations of the plume develop mainly 

southward for 4.0 ÷ 4.5 km and towards the coastline: in this zone SSC is on 

average around 0.15 ÷ 0.20 kg/m 3 . It has to be noticed that the map 

corresponding to maximum concentration is time independent; therefore it is not 

straightforward to identify a strict correlation between the instantaneous 

direction of the current and the development of the plume. 

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Latitude [°] 




19.3577°, LAT 40.7916°) 

The shape of the plume associated to maximum concentration generated by 

release point n°4 (Figure 5-11) is similar to the one described for point n°3, both 

maximum concentration and extension. 

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Latitude [°] 




19.3500°, LAT 40.7911°) 

In point n°5 the sediment is released only for one day; for this reason the 

maximum values of SSC are significantly lower than in the other points. In 

particular the maximum SSC, averaged in the first 20 m of the water column, is 

located in correspondence to the release source, with local values around 0.32 

kg/m 3 (Figure 5-12). The concentration quickly drops down to 0.10 kg/ m 3 after 

few hundred meters north and south of the release point. 

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Latitude [°] 




19.3280°, LAT 40.7897°) 


During the spring/summer months, considering release point n°1 (Figure 5-13), 

the maximum SSC, averaged in the first 20 m of the water column, can be found 

in the area of the cofferdam with concentrations that locally, due to the limited 

water depth, can reach 2.8 kg/m 3 . 

Out of the area of the cofferdam, the concentration of suspended sediment is 

still higher than 0.1 kg/ m 3 for the first 1,000 m west of the cofferdam, 800 m 

south and 200m north. 

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Latitude [°] 



the water column, during spring/summer months for release point n°1 (LON 

19.3734°, LAT 40.7924°) 

The shape of the maximum concentration plume generated by release in point 

n°2 looks very similar to the one obtained for point n°1. 

In this case (Figure 5-14), the maximum SSC, averaged in the first 20 m of the 

water column, is located in correspondence to the release sources with values 

around 1.00 kg/m 3 . Relevant concentrations, with values around 0.60 kg/m 3 , 

can be found between the release points and the coast. Inside the area of the 

cofferdam the SSC is around 0.35 kg/m 3 . 

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Latitude [°] 



the water column, during spring/summer months for release point 2 (LON 

19.3655°, LAT 40.7921°) 


first 20 m of the water column, is located in correspondence to the release 

sources with values of about 1.1 kg/m 3 . 

Significant concentration, higher than 0.1 kg/m 3 can be found around the release 

point in a circular area characterized by a radius of approximately 2 km. 

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Latitude [°] 



the water column, during spring/summer months for release point n°3 (LON 

19.3577°, LAT 40.7916°) 

The shape of the maximum suspended sediment concentration plume generated 

by the sediment release in point n°4 looks similar to the one obtained for point 

n°3 but it is more elongated in the direction perpendicular to the coast (Figure 

5-16). 

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Latitude [°] 



the water column during spring/summer months for release point n°4 (LON 

19.3500°, LAT 40.7911°) 

The plume of the maximum suspended sediment concentration generated by 

release point n°5 is very limited both in extension and magnitude (Figure 5-17) 

due to the reduced duration of the release (only one day). In this case the 

maximum SSC, averaged in the first 20 m of the water column, is located in 

correspondence to the release source with values of about 0.18 kg/m 3 . 

The concentration quickly drops to 0.10 kg/ m 3 after few hundred meters south 

of the release point. 

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Latitude [°] 



the water column during spring/summer months for release point n°5 (LON 

19.3280°, LAT 40.7897°) 


This scenario is used to simulate the resuspension of sediment due to a storm 

event which determines both significant wave generated long shore currents 

(Section 4.4) and strong bed shear stresses due to the direct action of wave 

breaking. 

Since the dredging operations will be suspended during storm conditions, this 

scenario is relevant in terms of resuspension of the amount of dredged sediment 

which will be temporarily deposited close to the dredged channel during the 

operations. The assumption for scenario 3 is that dredging operations will occur 

in the spring/summer period, which is characterized by a lower frequency and 

magnitude of storms (same meteomarine conditions assumed for scenario 2). 

In the map (Figure 5-18) illustrating the maximum SSC over the 15-day period 

(the duration of the storm is only 48 h but the suspended sediment dispersion in 

the model domain of course continues) it is possible to observe that the plume is 

distributed southward of the deposit. The maximum values of concentration is 

around 0.12 kg/m 3 in the area closer to the temporary sediment deposit and 

close to the coastline, while it is less relevant proceeding offshore. 

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In terms of evolution in time of the plume (plots in Appendix E), the maximum 

concentration corresponds to the peak of the storm. After the peak, the SSC 

decreases and it becomes equal to zero already at the end of the storm in the 

proximity of the temporary deposit. 

The approach followed for scenario 3 aims at supporting the environmental 

impact analysis of the dredging operations. It has to be noticed that it is 

recommended to investigate in detail both the stability of the temporary deposit 

of sediment and the risk of natural backfilling of the access channel during the 

storm. 

Latitude [°] 



the water column, for hydrodynamic scenario 3 

5.6 Settling of fine sediment in the model domain 

Following a specific request from TAP, the settling of fine sediment in the 

model domain has been investigated. In the autumn/winter scenario, the 

combination of very small settling velocity and relatively high current speed 

prevents the fine suspended sediment to settle within the model domain in the 

time window of the simulation: in particular, almost 100% of the fine sediment 

in the water column goes out of the model domain after only 3 days from the 

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time of release (over a wide front and very low concentration). The amount of 

fine sediment which settles in the model domain is not relevant. 

In the spring/summer scenario the average current speed is lower so only 90% 

of the fine suspended sediment goes out of the domain after 15 days from the 

time of release (again over a wide front and very low concentration). The 

remaining 10%, however, still remains suspended in the water column and in 

this case, as for scenario 1, the amount of fine sediment which settles in the 

model domain is not relevant. 

5.7 Settling of sand in the model domain 

As illustrated in Chapter 5.1, the numerical modelling of the sediment dispersion 

only refers to the fine fraction of the material. This choice derives from the 

assumption that the sand fraction will settle nearby the release points, therefore 

being not relevant from an environmental impact perspective. 

Following a specific request from TAP, a rough estimation of the amount of sand 

fraction which will settle around the release point has been investigated. 

The amount of dredged material in terms of sand fraction is calculated as the 

difference of the already used dredging rates (total and fine fraction) illustrated 

in Table 5-3. Through simple desktop calculations involving settling velocity and 

current velocity, most of the released material (sand fraction) will settle in the 

first 100 m from each release point. 

The average volume of deposited sand is quite similar in the points along the 

access channel (points n°1, n°2, n°3, n°4) while it is much smaller in point n°5. 

A rough estimation for points n°1, n°2, n°3, n°4 brings approximately 7,500 

g/m 2 of settled sand within the 100 m radius area, while for point n°5 the settled 

sand is around 350 g/m 2 . 

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6 CONCLUSIONS 

This numerical modelling study aims at supporting the Environmental and Social 

Impact Assessment (ESIA) for the offshore part of the Albanian landfall of the 

TAP. The pipeline is planned to go from Italy (Puglia) to Albania, covering a 

distance of more than 100 km. 

In particular, the modeling study is focused on simulating the dispersion and fate 

of suspended sediment occurring during dredging operations. During dredging, 

both sand fraction and fine fraction are released in the water column. The sand 

fraction is assumed to settle nearby the release point and therefore its 

environmental impact is generally negligible. Following the above assumption, 

the numerical model only aimed at simulating the dispersion and fate of the fine 

fraction of the sediment, which can have a significant environmental impact 

since it can remain in suspension for a long time and migrate to sensitive areas. 

The meteomarine conditions which have been assumed as representative of 

typical conditions at the Albanian landfall of the TAP derive from an accurate 

processing of collected data of winds, waves, both yearly and seasonal, tidal 

variations and circulation in the southern Adriatic Sea; three meteomarine 

scenarios have been finally selected as representative of typical conditions at the 

Albanian landfall of the TAP: 

 

 

 

scenario 1: representative meteomarine conditions during autumn/winter 

season as wind, tide, currents from the general circulation of the Adriatic 

Sea, temperature and salinity profile; 

scenario 2: representative meteomarine conditions during spring/summer 

season as wind, tide, currents from the general circulation of the Adriatic 

Sea, temperature and salinity profile; 

scenario 3: representative meteomarine conditions for a spring/summer 

storm wave event 

In autumn/winter conditions (scenario 1), the currents from the general 

circulation of the Adriatic Sea, which is the main hydrodynamic forcing at the 

Albanian landfall of the TAP, are frequently directed from south to north and the 

vertical stratification of temperature and salinity is limited. This leads to quite 

uniform magnitude of currents along the water column. In spring/summer 

conditions (scenario 2) the currents from the general circulation of the Adriatic 

Sea are frequently directed from north to south but, due to a significant thermal 

stratification of the water column, significant differences in the hydrodynamic 

field can be noticed along the water column. 

Another important forcing that plays an important role in the generation of the 

current field is the wind, but its influence is only relevant at surface. 

For scenario 3, a relatively severe wave event characterized by a duration of 48 

hours has been considered. This scenario therefore includes the effect of wave 

breaking and wave generated currents. The presence of the temporary amount 

of sediment nearby the dredged channel locally determines shallow water 

conditions, above which wave breaking can dissipate a great part of the energy 

associated to the incident wave. The model results show higher values of current 

speed where the temporary deposit will be placed (shallow water, more severe 

wave breaking). On the contrary, inside the channel, due to the local deepening of 

the seabed, the current speed decreases. 

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Both the hydrodynamic and the mud transport model have been setup considering 

different bathymetric conditions in relation to the progress of the dredging 

operations. The sediment dispersion model is fully integrated with the 

hydrodynamic model. Each simulation of the sediment model is characterized by a 

duration of 15 days, during which the plume of suspended sediment released 

during dredging operations or during a storm changes in extension, shape and 

concentration according to hydrodynamics (advection) and dispersion conditions. 

The sediment dispersion model has been implemented for five release locations 

along the pipeline route, each one characterized by a specific sediment release in 

the water column, depending on the dredging rate, on the dredging method 

(Cutter Suction Dredger) and on the local percentage of the fine fraction. 

The results of the sediment dispersion model showed a high variability of the 

distribution of the suspended sediment concentration depending on the season 

and on the release point. In general, the stronger currents during autumn/winter 

conditions determine a shape of the sediment plume which is almost parallel to 

the coast, while during the spring/summer season the currents are weaker and 

the plume is more uniformly distributed around the release location. In both 

cases the concentration of suspended sediment is higher than 0.5 kg/m 3 in the 

proximity of the release point, while a concentration higher than 0.2 kg/m 3 can 

be found up to 2÷3 km from the release points. Offshore of the access channel, 

the volume of the dredged sediment is significantly lower, leading to very low 

concentration of suspended sediment released from the location which is 

representative of this stretch. 

In the third scenario, the release of sediment is not due to dredging operations 

but it is generated by the effect of wave breaking in shallow water. The results of 

the third scenario showed that the plume is distributed southward of the 

temporary deposit. The maximum values of concentration is around 0.12 kg/m 3 

in the area closer to the temporary sediment deposit and close to the coastline, 

while it is less relevant proceeding offshore. 

It has to be noticed that the Albanian landfall of the Trans Adriatic Pipeline is 

located very close to two important river mouths: Seman rivers to the north and 

Vjosa river to the south. Considering the relevance of these two rivers and their 

basins, although without available data, there is a high probability that the 

background suspended sediment concentration of the water column in the area, 

which has been assumed equal to zero in the simulations, is naturally high. 

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7 REFERENCES 

[1] Wind and Wave Mediterranean Atlas, Medatlas project led by a 

consortium of six companies located in France, Italy and Greece, 1999- 

2004. 

[2] Integrated Project Water and Global Change (WATCH), European Union 

Sixth Framework Programme (EU FP6), 2007-2011. 

[3] Mediterranean Forecasting System (MFS) database available within the 

framework of MyOcean EU Project. 

[4] Database CM-93, Norwegian C-MAP, release 2011. 

[5] Tool MIKE C-MAP, Danish Hydraulic Institute (DHI), release 2011. 

[6] MIKE 3 HD FM, Danish Hydraulic Institute (DHI), release 2011. 

[7] MIKE 3 MT FM, Danish Hydraulic Institute (DHI), release 2011. 

[8] Måling af insitu faldhastigheder af klappet havnesediment i Grådyb. 

GRAS A/S July 2004. 

[9] Edelvang, K A study of the significance of flocculation for the in situ 

settling velocities in a tidal channel. Advanced Limnology 47: 462-467. 

1996. 

[10] Edelvang, K The significance of particle aggregation in an estuarine 

environment. Case studies from the Lister Dyb tidal area. Geographica 

Hafnesia A5: 1-105, 1996. 

[11] Edelvang, K Tial variation in the settling diameters of suspended matter 

on a tidal mud flat. Helgoländer meeresuntersuchungen 51: 269-279, 

1997. 

[12] Edelvang, K Austen, I The temporal variation of flocs and fecal pellets in 

a tidal channel. Estuarine, Coastal and shelf science 44: 361-367, 1997. 

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A P P E N D I X A 

Yearly sea temperature 

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Figure 1 

Sea temperature during 2006 at three different depths (0, -10, -20 m m.s.l.) 

offshore the Albanian landfall site. Source: the trends are processed by DHI on the 

basis of the oceanographic data downloaded from MyOcean website 

(http://www.myocean.org/) for the point of coordinates LON 19.25°, LAT 40.75° 

Figure 2 





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Figure 3 





Figure 4 





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Figure 5 





Figure 6 





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A P P E N D I X B 

Yearly sea salinity 

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Figure 7 

Sea salinity during 2006 at three different depths (0, -10, -20 m m.s.l.) 

offshore the Albanian landfall site. Source: the trends are processed by DHI 



40.75° 

Figure 8 





40.75° 

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Figure 9 





40.75° 

Figure 10 





40.75° 

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Figure 11 





40.75° 

Figure 12 





40.75° 

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A P P E N D I X C 

Offshore currents speed and direction 

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Figure 13 Current speed and direction during January 2006 at three different depths (0, 

-10, -20 m m.s.l.) offshore the Albanian landfall site. Source: the trends are 

processed by DHI on the basis of the oceanographic data downloaded from 

MyOcean website (http://www.myocean.org/) for the point of coordinates 

LON 19.25°, LAT 40.75° 





LON 19.25°, LAT 40.75° 

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LON 19.25°, LAT 40.75° 





LON 19.25°, LAT 40.75° 

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LON 19.25°, LAT 40.75° 





LON 19.25°, LAT 40.75° 

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Figure 19 

Current speed and direction during February 2006 at three different depths 

(0, -10, -20 m m.s.l.) offshore the Albanian landfall site. Source: the trends 

are processed by DHI on the basis of the oceanographic data downloaded 

from MyOcean website (http://www.myocean.org/) for the point of 

coordinates LON 19.25°, LAT 40.75° 

Figure 20 






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Figure 22 






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Figure 24 






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Figure 25 Current speed and direction during March 2006 at three different depths (0, - 

10, -20 m m.s.l.) offshore the Albanian landfall site. Source: the trends are 



LON 19.25°, LAT 40.75° 





LON 19.25°, LAT 40.75° 

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Figure 31 Current speed and direction during April 2006 at three different depths (0, - 




LON 19.25°, LAT 40.75° 





LON 19.25°, LAT 40.75° 

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Figure 37 Current speed and direction during May 2006 at three different depths (0, - 




LON 19.25°, LAT 40.75° 





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Figure 43 Current speed and direction during June 2006 at three different depths (0, - 




LON 19.25°, LAT 40.75° 





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Figure 49 Current speed and direction during July 2006 at three different depths (0, - 




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Figure 55 Current speed and direction during August 2006 at three different depths (0, 




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Figure 61 

Current speed and direction during September 2006 at three different depths 





Figure 62 






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Figure 64 






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Figure 65 






Figure 66 






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Figure 67 Current speed and direction during October 2006 at three different depths (0, 




LON 19.25°, LAT 40.75° 





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Figure 73 

Current speed and direction during November 2006 at three different depths 





Figure 74 






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Figure 76 






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Figure 77 






Figure 78 

Current speed and direction during December 2006 at three different depths 





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Figure 79 


(0, -10, -20 m m.s.l.) offshore the landfall site. Source: the trends are 



LON 19.25°, LAT 40.75° 

Figure 80 






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Figure 81 






Figure 82 






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A P P E N D I X D 

Plots representing maps of currents 

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Figure 83 Location of the release points. For points n°1 (P1), n°2 (P2), n°3 (P3), n°4 

(P4), due to the expected dredging methodology, two release sources are 

considered: one is located inside the channel, where the sediment is dredged, 

and one outside the channel, where the material is temporarily deposited. For 

point n°5 only one release source, inside the trench, has been assumed. 

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Figure 84 


Hydrodynamic field at surface for the Albanian landfall site (bathymetry n°1) 

during autumn/winter representative conditions (04/01/2008) 

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Figure 85 

Hydrodynamic field at intermediate depth for the Albanian landfall site 

(bathymetry n°1) during autumn/winter representative conditions 

(04/01/2008) 

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Figure 86 

Hydrodynamic field at sea bed depth for the Albanian landfall site 


(04/01/2008) 

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Figure 87 



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Figure 88 




(04/01/2008) 

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Figure 89 




(04/01/2008) 

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Figure 90 



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Figure 91 



(04/01/2008) 

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Figure 92 



(04/01/2008) 

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Figure 93 



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Figure 94 



(13/01/2008) 

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Figure 95 



(13/01/2008) 

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Figure 96 



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Figure 97 



(13/01/2008) 

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Figure 98 



(13/01/2008) 

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Figure 99 




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Figure 100 Hydrodynamic field at intermediate depth for the Albanian landfall site 


(13/01/2008) 

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Figure 101 Hydrodynamic field at sea bed depth for the Albanian landfall site 


(13/01/2008) 

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Figure 102 Hydrodynamic field at surface for the Albanian landfall site (bathymetry n°1) 

during spring/summer representative conditions (23/06/2008) 

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(bathymetry n°1) during spring/summer representative conditions 

(23/06/2008) 

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(23/06/2008) 

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Figure 120 Hydrodynamic field at surface for the Albanian landfall site (bathymetry 

includes the temporary deposit of dredged sediment) during the growing 


is bigger than 1.0 m (23/06/2008 – h. 7.00) 

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includes the temporary deposit of dredged sediment) during the peak of the 

storm, when the wave event reaches the maximum significant wave height 

equal to 2.5 m (23/06/2008 – h. 16.00) 

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includes the temporary deposit of dredged sediment) during the decreasing 


again becomes smaller than 1.0 m (24/06/2008 – h. 11.00) 

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A P P E N D I X E 

Plots representing maps of suspended sediment 

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Figure 129 Location of the release points. For points n°1 (P1), n°2 (P2), n°3 (P3), n°4 

(P4), due to the expected dredging methodology, two release sources are 

considered: one is located inside the channel, where the sediment is dredged, 

and one outside the channel, where the material is temporarily deposited. For 

point n°5 only one release source, inside the trench, has been assumed. 

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Latitude [°] 


Figure 130 Suspended Sediment Concentration field at surface for the Albanian landfall 

site (bathymetry n°3) during autumn/winter representative conditions 

(04/01/2008) for release point n°1 (LON 19.3734°, LAT 40.7924°) 

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Figure 131 Suspended Sediment Concentration field at intermediate depth for the 

Albanian landfall site (bathymetry n°3) during autumn/winter representative 

conditions (04/01/2008) for release point n°1 (LON 19.3734°, LAT 40.7924°) 

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Figure 132 Suspended Sediment Concentration field at sea bed depth for the Albanian 

landfall site (bathymetry n°3) during autumn/winter representative 


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site (bathymetry n°3) during spring/summer representative conditions 


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Albanian landfall site (bathymetry n°3) during spring/summer representative 


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landfall site (bathymetry n°3) during spring/summer representative 


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site (bathymetry includes the temporary deposit of dredged sediment) during 

the growing phase of the storm, at the first time step at which the significant 


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Latitude [°] 



Albanian landfall site (bathymetry includes the temporary deposit of dredged 

sediment) during the growing phase of the storm, at the first time step at 

which the significant wave height is bigger than 1.0 m (23/06/2008 – h. 

7.00) 

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Latitude [°] 



landfall site (bathymetry includes the temporary deposit of dredged 

sediment) during the growing phase of the storm, at the first time step at 

which the significant wave height is bigger than 1.0 m (23/06/2008 – h. 

7.00) 

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the peak of the storm, when the wave event reaches the maximum 

significant wave height equal to 2.5 m (23/06/2008 – h. 16.00) 

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sediment) during the peak of the storm, when the wave event reaches the 

maximum significant wave height equal to 2.5 m (23/06/2008 – h. 16.00) 

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Latitude [°] 




sediment) during the peak of the storm, when the wave event reaches the 

maximum significant wave height equal to 2.5 m (23/06/2008 – h. 16.00) 

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the decreasing phase of the storm, at the first time step at which the 

significant wave height again becomes smaller than 1.0 m (24/06/2008 – h. 

11.00) 

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Latitude [°] 




sediment) during the decreasing phase of the storm, at the first time step at 

which the significant wave height again becomes smaller than 1.0 m 

(24/06/2008 – h. 11.00) 

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Latitude [°] 




sediment) during the decreasing phase of the storm, at the first time step at 

which the significant wave height again becomes smaller than 1.0 m 

(24/06/2008 – h. 11.00) 

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A P P E N D I X F 

Description of MIKE 3 HD FM Model 

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MIKE 21 & MIKE 3 FLOW MODEL FM 

Hydrodynamic Module 

Short Description




Agern Allé 5 

DK-2970 Hørsholm 

Denmark 

Tel: +45 4516 9200 

Support: +45 4516 9333 

Fax: +45 4516 9292 

mikebydhi@dhigroup.com 

www.mikebydhi.com 

MIKE213_HD_FM_Short_Description.docx/ AJS/EBR/2011Short_Descriptions.lsm/2011-06-10 

Hydrodynamic Module



MIKE 21 & MIKE 3 Flow Model FM 

The Flow Model FM is a comprehensive 

modelling system for two- and three-dimensional 

water modelling developed by DHI. The 2D and 

3D models carry the same names as the classic 

DHI model versions MIKE 21 & MIKE 3 with an 

„FM‟ added referring to the type of model grid - 

Flexible Mesh. 

The modelling system has been developed for 

complex applications within oceanographic, 

coastal and estuarine environments. However, 

being a general modelling system for 2D and 3D 

free-surface flows it may also be applied for 

studies of inland surface waters, e.g. overland 

flooding and lakes or reservoirs. 

MIKE 21 & MIKE 3 Flow Model FM is a general 

hydrodynamic flow modelling system based on a finite 

volume method on an unstructured mesh 

DHI‟s Flexible Mesh (FM) series includes the 

following: 

Flow Model FM modules 

Hydrodynamic Module, HD 

Transport Module, TR 

Ecology Module, ECO Lab 

Oil Spill Module, ELOS 

Sand Transport Module, ST 

Mud Transport Module, MT 

Particle Tracking Module, PT 

Wave module 

Spectral Wave Module, SW 

The FM Series meets the increasing demand for 

realistic representations of nature, both with 

regard to „look alike‟ and to its capability to model 

coupled processes, e.g. coupling between currents, 

waves and sediments. Coupling of modules is 

managed in the Coupled Model FM. 

All modules are supported by advanced user 

interfaces including efficient and sophisticated 

tools for mesh generation, data management, 

2D/3D visualization, etc. In combination with 

comprehensive documentation and support, the 

FM series forms a unique professional software 

tool for consultancy services related to design, 

operation and maintenance tasks within the marine 

environment. 

An unstructured grid provides an optimal degree 

of flexibility in the representation of complex 

geometries and enables smooth representations of 

boundaries. Small elements may be used in areas 

where more detail is desired, and larger elements 

used where less detail is needed, optimising 

information for a given amount of computational 

time. 

The spatial discretisation of the governing 

equations is performed using a cell-centred finite 

volume method. In the horizontal plane an 

unstructured grid is used while a structured mesh 

is used in the vertical domain (3D). 

This document provides a short description of the 

Hydrodynamic Module included in MIKE 21 & 

MIKE 3 Flow Model FM. 

Example of computational mesh for Tamar Estuary, UK 

Short Description Page 1




MIKE 21 & MIKE 3 FLOW MODEL FM supports both Cartesian and spherical coordinates. Spherical coordinates are 

usually applied for regional and global sea circulation applications. The chart shows the computational mesh and 

bathymetry for the planet Earth generated by the MIKE Zero Mesh Generator 

MIKE 21 & MIKE 3 Flow Model FM - 

Hydrodynamic Module 

The Hydrodynamic Module provides the basis for 

computations performed in many other modules, 

but can also be used alone. It simulates the water 

level variations and flows in response to a variety 

of forcing functions on flood plains, in lakes, 

estuaries and coastal areas. 

Application Areas 

The Hydrodynamic Module included in MIKE 21 

& MIKE 3 Flow Model FM simulates unsteady 

flow taking into account density variations, 

bathymetry and external forcings. 

The choice between 2D and 3D model depends on 

a number of factors. For example, in shallow 

waters, wind and tidal current are often sufficient 

to keep the water column well-mixed, i.e. 

homogeneous in salinity and temperature. In such 

cases a 2D model can be used. In water bodies 

with stratification, either by density or by species 

(ecology), a 3D model should be used. This is also 

the case for enclosed or semi-enclosed waters 

where wind-driven circulation occurs. 

Typical application areas are 

Assessment of hydrographic conditions for 

design, construction and operation of 

structures and plants in stratified and nonstratified 

waters 

Environmental impact assessment studies 

Coastal and oceanographic circulation studies 

Optimization of port and coastal protection 

infrastructures 

Lake and reservoir hydrodynamics 

Cooling water, recirculation and desalination 

Coastal flooding and storm surge 

Inland flooding and overland flow modelling 

Forecast and warning systems 

Example of a global tide application of MIKE 21 Flow 

Model FM. Results from such a model can be used as 

boundary conditions for regional scale forecast or hindcast 

models 

Page 2 

Hydrodynamic Module



The MIKE 21 & MIKE 3 Flow Model FM also 

support spherical coordinates, which makes both 

models particularly applicable for global and 

regional sea scale applications. 

Typical applications with the MIKE 21 & MIKE 3 Flow 

Model FM include cooling water recirculation and 

ecological impact assessment (eutrophication) 

The Hydrodynamic Module is together with the 

Transport Module (TR) used to simulate the 

spreading and fate of dissolved and suspended 

substances. This module combination is applied in 

tracer simulations, flushing and simple water 

quality studies. 

Example of a flow field in Tampa Bay, FL, simulated by 

MIKE 21 Flow Model FM 

Tracer simulation of single component from outlet in the 

Adriatic, simulated by MIKE 21 Flow Model FM HD+TR 

Study of thermal recirculation 

Prediction of ecosystem behaviour using the MIKE 21 & 

MIKE 3 Flow Model FM together with ECO Lab 





The Hydrodynamic Module can be coupled to the 

Ecological Module (ECO Lab) to form the basis 

for environmental water quality studies 

comprising multiple components. 

Furthermore, the Hydrodynamic Module can be 

coupled to sediment models for the calculation of 

sediment transport. The Sand Transport Module 

and Mud Transport Module can be applied to 

simulate transport of non-cohesive and cohesive 

sediments, respectively. 

In the coastal zone the transport is mainly 

determined by wave conditions and associated 

wave-induced currents. The wave-induced 

currents are generated by the gradients in radiation 

stresses that occur in the surf zone. The Spectral 

Wave Module can be used to calculate the wave 

conditions and associated radiation stresses. 

Coastal application (morphology) with coupled MIKE 21 

HD, SW and ST, Torsminde harbour Denmark 

Model bathymetry of Taravao Bay, Tahiti 

Example of Cross reef currents in Taravao Bay, Tahiti simulated with MIKE 3 Flow Model FM. The circulation and renewal of 

water inside the reef is dependent on the tides, the meteorological conditions and the cross reef currents, thus the circulation 

model includes the effects of wave induced cross reef currents 

Page 4 

Hydrodynamic Module



Computational Features 

The main features and effects included in 

simulations with the MIKE 21 & MIKE 3 Flow 

Model FM – Hydrodynamic Module are the 

following: 

Flooding and drying 

Momentum dispersion 

Bottom shear stress 

Coriolis force 

Wind shear stress 

Barometric pressure gradients 

Ice coverage 

Tidal potential 

Precipitation/evaporation 

Wave radiation stresses 

Sources and sinks 

Model Equations 

The modelling system is based on the numerical 

solution of the two/three-dimensional incompressible 

Reynolds averaged Navier-Stokes equations 

subject to the assumptions of Boussinesq and of 

hydrostatic pressure. Thus, the model consists of 

continuity, momentum, temperature, salinity and 

density equations and it is closed by a turbulent 

closure scheme. The density does not depend on 

the pressure, but only on the temperature and the 

salinity. 

For the 3D model, the free surface is taken into 

account using a sigma-coordinate transformation 

approach or using a combination of a sigma and z- 

level coordinate system. 

Below the governing equations are presented 

using Cartesian coordinates. 

The local continuity equation is written as 

u 

v 

w 

S 

x 

y 

z 

and the two horizontal momentum equations for 

the x- and y-component, respectively 

2 

u 

u 

vu 

wu 

 

t 

x 

y 

z 

1 pa 

g 

 

x 

 

0 

0 

1 pa 

g 

 

y 

 

 

 

z 

 

dz F 

x 

 

fv g 

x 

u 

u 

 

 

t usS 

z 

z 

 

2 

v 

v 

uv 

wv 

 

fu g 

t 

y 

x 

z 

y 

0 

0 

 

 

z 

 

v 

 

dz Fv 

 

t vs 

S 

y 

z 

z 

 

Temperature and salinity 

In the Hydrodynamic Module, calculations of the 

transports of temperature, T, and salinity, s follow 

the general transport-diffusion equations as 

T 

uT 

vT 

wT 

F 

t 

x 

y 

z 

s 

us 

vs 

ws 

F 

t 

x 

y 

z 

T 

 

D 

z 

 

s 

v 

 

D 

z 

 

T 

 

z 

v 

 

 

 

H T S 

s 

 

s 

z 

 

s 

s 

S 

Unstructured mesh technique gives the maximum degree of 

flexibility, for example: 1) Control of node distribution allows for 

optimal usage of nodes 2) Adoption of mesh resolution to the 

relevant physical scales 3) Depth-adaptive and boundary-fitted 

mesh. Below is shown an example from Ho Bay Denmark with the 

approach channel to the Port of Esbjerg 





The horizontal diffusion terms are defined by 

 

, s h h 

x 

x 

y 

y 

 

F 

F D D T 

s 

T , 

The equations for two-dimensional flow are 

obtained by integration of the equations over 

depth. 

Heat exchange with the atmosphere is also 

included. 

Symbol list 

t 

time 

x, y, z: Cartesian coordinates 

u, v, w: flow velocity components 

T, s: temperature and salinity 

D v : 

H : 

vertical turbulent (eddy) diffusion 

coefficient 

source term due to heat exchange 

with atmosphere 

S: magnitude of discharge due to point 

sources 

T s , s s : temperature and salinity of source 

F T , F s , F c : 

D h : 

h : 

horizontal diffusion terms 

horizontal diffusion coefficient 

depth 

Solution Technique 

The spatial discretisation of the primitive 


volume method. The spatial domain is discretised 

by subdivision of the continuum into nonoverlapping 

elements/cells. 

In the horizontal plane an unstructured mesh is 

used while a structured mesh is used in the vertical 

domain of the 3D model. In the 2D model the 

elements can be triangles or quadrilateral 

elements. In the 3D model the elements can be 

prisms or bricks whose horizontal faces are 

triangles and quadrilateral elements, respectively. 

Model Input 

Input data can be divided into the following 

groups: 

Domain and time parameters: 

computational mesh (the coordinate type is 

defined in the computational mesh file) 

and bathymetry 

simulation length and overall time step 

Calibration factors 

bed resistance 

momentum dispersion coefficients 

wind friction factors 

Initial conditions 

water surface level 

velocity components 

Boundary conditions 

closed 

water level 

discharge 

Other driving forces 

wind speed and direction 

tide 

source/sink discharge 

wave radiation stresses 

Principle of 3D mesh 

View button on all the GUIs in MIKE 21 & MIKE 3 FM HD 

for graphical view of input and output files 

Page 6 

Hydrodynamic Module



3D visualization of a computational mesh 

The Mesh Generator is an efficient MIKE Zero tool for the 

generation and handling of unstructured meshes, including 

the definition and editing of boundaries 

Providing MIKE 21 & MIKE 3 Flow Model FM 

with a suitable mesh is essential for obtaining 

reliable results from the models. Setting up the 

mesh includes the appropriate selection of the area 

to be modelled, adequate resolution of the 

bathymetry, flow, wind and wave fields under 

consideration and definition of codes for defining 

boundaries. 

If wind data is not available from an atmospheric 

meteorological model, the wind fields (e.g. 

cyclones) can be determined by using the windgenerating 

programs available in MIKE 21 

Toolbox. 

Global winds (pressure & wind data) can be 

downloaded for immediate use in your simulation. 

The sources of data are from GFS courtesy of 

NCEP, NOAA. By specifying the location, 

orientation and grid dimensions, the data is 

returned to you in the correct format as a spatial 

varying grid series or a time series. The link is: 

www.mikebydhi.com/Download/DocumentsAndTools/Tools/Av 

ailableData.aspx 

2D visualization of a computational mesh (Odense 

Estuary) 

Bathymetric values for the mesh generation can 

e.g. be obtained from the MIKE by DHI product 

MIKE C-Map. MIKE C-Map is an efficient tool 

for extracting depth data and predicted tidal 

elevation from the world-wide Electronic Chart 

Database CM-93 Edition 3.0 from Jeppesen 

Norway. 

The chart shows a hindcast wind field in the North Sea 

and Baltic Sea as wind speed and wind direction 





Model Output 

Computed output results at each mesh element and 

for each time step consist of: 

Basic variables 

water depth and surface elevation 

flux densities in main directions 

velocities in main directions 

densities, temperatures and salinities 

Additional variables 

Current speed and direction 

Wind velocities 

Air pressure 

Drag coefficient 

Precipitation/evaporation 

Courant/CFL number 

Eddy viscosity 

Element area/volume 

The output results can be saved in defined points, 

lines and areas. In the case of 3D calculations the 

results are saved in a selection of layers. 

Output from MIKE 21 & MIKE 3 Flow Model 

FM is typically post-processed using the Data 

Viewer available in the common MIKE Zero shell. 

The Data Viewer is a tool for analysis and 

visualization of unstructured data, e.g. to view 

meshes, spectra, bathymetries, results files of 

different format with graphical extraction of time 

series and line series from plan view and import of 

graphical overlays. 

Vector and contour plot of current speed at a vertical 

profile defined along a line in Data Viewer in MIKE Zero 

Validation 

Prior to the first release of MIKE 21 & MIKE 3 

Flow Model FM the model has successfully been 

applied to a number of rather basic idealized 

situations for which the results can be compared 

with analytical solutions or information from the 

literature. 

The domain is a channel with a parabola-shaped bump in 

the middle. The upstream (western) boundary is a 

constant flux and the downstream (eastern) boundary is a 

constant elevation. Below: the total depths for the 

stationary hydraulic jump at convergence. Red line: 2D 

setup, green line: 3D setup, black line: analytical solution 

The Data Viewer in MIKE Zero – an efficient tool for 

analysis and visualization of unstructured data including 

processing of animations. Above screen dump shows 

surface elevations from a model setup covering Port of 

Copenhagen 

Page 8 

Hydrodynamic Module



A dam-break flow in an L-shaped channel (a, b, c): 

a) Outline of model setup showing the location of 

gauging points 

c) Contour plots of the surface elevation at T = 1.6 s 

(top) and T = 4.8 s (bottom) 

b) Comparison between simulated and measured water 

levels at the six gauge locations. 

(Blue) coarse mesh (black) fine mesh and (red) 

measurements 

Example from Ho Bay, a tidal estuary (barrier island coast) 

in South-West Denmark with access channel to the Port of 

Esbjerg. Below: Comparison between measured and 

simulated water levels 

The model has also been applied and tested in 

numerous natural geophysical conditions; ocean 

scale, inner shelves, estuaries, lakes and overland, 

which are more realistic and complicated than 

academic and laboratory tests. 





The user interface of the MIKE 21 and MIKE 3 Flow Model FM (Hydrodynamic Module), including an example of the 

extensive Online Help system 

Graphical User Interface 

The MIKE 21 & MIKE 3 Flow Model FM are 

operated through a fully Windows integrated 

graphical user interface (GUI). Support is 

provided at each stage by an Online Help system. 

The common MIKE Zero shell provides entries 

for common data file editors, plotting facilities and 

utilities such as the Mesh Generator and Data 

Viewer. 

Overview of the common MIKE Zero utilities 

Page 10 

Hydrodynamic Module



Parallelisation 

The computational engines of the MIKE 21/3 FM 

series are available in versions that have been 

parallelised using both shared memory (OpenMP) 

as well as distributed memory architecture (MPI). 

The result is much faster simulations on systems 

with many cores. 

MIKE 21/3 FM speed-up using multicore PCs for Release 

2011 with distributed memory architecture (blue) and 

shared memory architecture that was part of Release 2009 

(green) 

Hardware and Operating System 

Requirements 

The MIKE 21 and MIKE 3 Flow Model FM 

Hydrodynamic Module supports Microsoft 

Windows XP Professional Edition (32 and 64 bit), 

Microsoft Windows Vista Business (32 and 64 bit) 

and Microsoft Windows 7 Enterprise (32 and 64 

bit). Microsoft Internet Explorer 6.0 (or higher) is 

required for network license management as well 

as for accessing the Online Help. 

The recommended minimum hardware 

requirements for executing MIKE 21 & MIKE 3 

Flow Model FM are listed below: 

Support 

News about new features, applications, papers, 

updates, patches, etc. are available here: 

www.mikebydhi.com/Download/DocumentsAndTools.aspx 

For further information on MIKE 21 and MIKE 3 

Flow Model FM software, please contact your 

local DHI office or the Software Support Centre: 

MIKE by DHI 

DHI 

Agern Allé 5 


Denmark 

Tel: +45 4516 9333 

Fax: +45 4516 9292 



References 

The MIKE 21 & MIKE 3 Flow Model FM are 

provided with comprehensive user guides, online 

help, scientific documentation, application 

examples and step-by-step training examples. 

Processor: 

Memory (RAM): 

Hard disk: 

Monitor: 

Graphic card: 

Media: 

3 GHz PC (or higher) 

4 GB (or higher) 


SVGA, resolution 1024x768 

32 MB RAM (or higher), 

32 bit true colour 

CD-ROM/DVD drive, 20 x 

speed (or higher) 





Petersen, N.H., Rasch, P. “Modelling of the Asian 

Tsunami off the Coast of Northern Sumatra”, 

presented at the 3rd Asia-Pacific DHI Software 

Conference in Kuala Lumpur, Malaysia, 21-22 

February, 2005 

French, B. and Kerper, D. Salinity Control as a 

Mitigation Strategy for Habitat Improvement of 

Impacted Estuaries. 7 th Annual EPA Wetlands 

Workshop, NJ, USA 2004. 

DHI Note, “Flood Plain Modelling using 

unstructured Finite Volume Technique” January 

2004 – download from 

www.mikebydhi.com/Download/DocumentsAndTools/PapersA 

ndDocs/Hydrodynamics.aspx 

Page 12 

Hydrodynamic Module



A P P E N D I X G 

Description of MIKE 3 MT FM Model 

22700172-01-00101.docx 

DHI Italia




Mud Transport Module 

Short Description




Agern Allé 5 


Denmark 

Tel: +45 4516 9200 

Support: +45 4516 9333 

Fax: +45 4516 9292 



MIKE213_MT_FM_ShortDescription.docx/AJS/HKH/ULU/KAE/2011Short_Descriptions.lsm/2011-06-17 

Mud Transport Module



MIKE 21 & MIKE 3 Flow Model FM 

– Mud Transport Module 

This document describes the Mud Transport 

Module (MT) under the comprehensive modelling 

system for two- and three-dimensional flows, the 

Flexible Mesh series, developed by DHI. 

The MT module includes a state-of-the-art mud 

transport model that simulates the erosion, 

transport, settling and deposition of cohesive 

sediment in marine, brackish and freshwater areas. 

The module also takes into account fine-grained 

non-cohesive material. 

With the FM series it is possible to combine and 

run the modules dynamically. If the morphological 

changes within the area of interest are within the 

same order of magnitude as the variation in the 

water depth, then it is possible to take the 

morphological impact on the hydrodynamics into 

consideration. This option for dynamic feedback 

between update of seabed and flow may be 

relevant to apply in shallow areas, for example, 

where long term effects are being considered. 

Furthermore it may be relevant in shallow areas 

where capital or considerable maintenance 

dredging is planned and similarly at sites where 

disposal of the dredged material takes place. 

Example of spreading of dredged material in Øresund, 

Denmark 

The MT module is an add-on module to MIKE 21 

& MIKE 3 Flow Model FM. It requires a coupling 

to the hydrodynamic solver and to the transport 

solver for passive components (Advection 

Dispersion module). The hydrodynamic basis is 

obtained with the MIKE 21 or MIKE 3 FM HD 

module. The influence of waves on the 

erosion/deposition patterns can be included by 

applying the Spectral Wave module, MIKE 21 FM 

SW. 

Example of sediment plume from a river near Malmö, 

Sweden 





Application Areas 

The MT module is used in a variety of cases 

where the erosion, dispersion, and deposition of 

cohesive sediments are of interest. Fine-grained 

sediment may cause impacts in different ways. In 

suspension, the fines may shadow areas over a 

time span, which can be critical for the survival of 

light-depending benthic fauna and flora. The finegrained 

sediment may deposit in areas where 

deposition is unwanted, for instance in harbour 

inlets. Furthermore, pollutants such as heavy 

metals and TBT are prone to adhere to the 

cohesive sediment. If polluted sediment is 

deposited in ecologically sensitive areas it may 

heavily affect local flora and fauna and water 

quality in general. 

Optimisation of dredging operations 

Siltation of harbours 

Siltation in access channels 

Cohesive sediment dynamics and morphology 

Dispersion of river plumes 

Erosion of fine-grained material under 

combined waves and currents 

Studies of dynamics of contaminated 

sediments 

Example of muddy estuary. Caravelas, Brazil 

Example of resuspension in the nearshore zone. 

Caravelas, Brazil. Assessment of resuspension may be 

relevant in for example dredging projects to identify 

sources and levels of background turbidity 

The estimation of siltation rates is an area where 

the MT module often is applied and also an 

important aspect to consider when designing new 

approach channels or deepening existing channels 

to allow access for larger vessels to the ports. 

Simulations of fine-grained sediment dynamics 

may contribute to optimise the design with regard 

to navigation and manoeuvrability on one hand 

and minimising the need for maintenance dredging 

on the other. 

The MT module has many application areas and 

some of the most frequently used are listed below: 

Dispersion of dredged material 

Computational Features 

The main features of the MIKE 21 & MIKE 3 

Flow Model FM Mud Transport module are: 

Multiple sediment fractions 

Multiple bed layers 

Flocculation 

Hindered settling 

Inclusion of non-cohesive sediments 

Bed shear stress from combined currents and 

waves 

Waves included as wave database or 2D time 

series 

Consolidation 

Morphological update of bed 

Tracking of sediment spills 

Example of modelled physical processes 

Page 2 




Model Equations 

The governing equations behind the MT module 

are essentially based on Mehta et al. (1989). The 

impact of waves is introduced through the bed 

shear stress. 

The cohesive sediment transport module or mud 

transport (MT) module deals with the movement 

of mud in a fluid and the interaction between the 

mud and the bed. 

The transport of the mud is generally described by 

the following equation (e.g. Teisson, 1991): 

i i i i i 

c 

uc 

vc 

wc 

w s c 

 

t 

x 

y 

z 

z 

i 

i 

 

Tx c 

 

 

Ty c 

 

 

Tz 

 

 

x 

i 

x 

y 

i 

y 

z 

i 

 

Tx 

Ty 

Tz 

i 

c 

 

 

z 

 

 

The transport of the cohesive sediment is handled 

by a transport solver for passive components (ADmodule). 

The settling velocity w s is a 

sedimentological process and as such it is 

described separately with the extra term 

using an operator splitting technique. 

Symbol list 

t 

time 

x, y, z: Cartesian co-ordinates 

u, v, w: flow velocity components 

D v : 

c i : 

w s i : 

Tx i : 

Tx : 

S i : 

vertical turbulent (eddy) diffusion 

coefficient 

i 

ws 

C 

z 

i 

S 

the i’th scalar component (defined as the 

mass concentration) 

fall velocity 

turbulent Schmidt number 

anisotropic eddy viscosity 

source term 

The bed interaction/update and the settling 

velocity terms are handled in the MT module. 

The sedimentological effects on the fluid density 

and viscosity (concentrated near-bed suspensions) 

are not considered as part of the mud process 

module. Instead they are provided as separate submodules 

as they are only relevant for higher 

suspended sediment concentrations (SSC). 

Mud plains in Loire river, France 

Settling velocity 

The settling velocity of the suspended sediment 

may be specified as a constant value. Flocculation 

is described as a relationship with the suspended 

sediment concentration as given in Burt (1986). 

Hindered settling can be applied if the suspended 

sediment concentration exceeds a certain level. To 

distinguish between three different settling 

regimes, two boundaries are defined, c floc and 

c hindered , being the concentrations where 

flocculation and hindered settling begins, 

respectively. 

Constant settling velocity 

Below a certain suspended sediment concentration 

the flocculation may be negligible and a constant 

settling velocity can be applied: 

w k 

c 

s 

c floc 

where w s is the settling velocity and k is the 

constant. 

Flocculation 

After reaching c floc , the sediment will begin to 

flocculate. Burt (1986) found the following 

relationship: 

c 

ws 

k 

 

 

sediment 

 

 

 

 

c 

floc 

c c 

hindered 

In which k is a constant, sediment is the sediment 

density, and is a coefficient termed settling 

index. 

Hindered settling 

After a relatively high sediment concentration 

(c hindered ) is reached, the settling columns of flocs 

begin to interfere and hereby reducing the settling 

velocity. Formulations given by Richardson and 





Zaki (1954) and Winterwerp (1999) are 

implemented. 

Deposition 

The deposition is described as (Krone, 1962): 

S w c 

D 

s 

b 

p 

D 

where w s is the settling velocity of the suspended 

sediment (m s -1 ), c b is the suspended sediment 

concentration near the bed, and p d is an 

expression of the probability of deposition: 

p 

d 

 

b 

1 

 

cd 

In the three-dimensional model, c b is simply equal 

to the sediment concentration in the water cell just 

above the sediment bed. 

In the two-dimensional model, two different 

approaches are available for computing c b . If the 

Rouse profile is applied, the near bed sediment 

concentration is related to the depth averaged 

sediment concentration by multiplying with a 

constant centroid height: 

c b 

c (centroid 

height) 

Teeter (1986) related the near bed concentrations 

to the Peclet number (P e ), the bed fluxes, and the 

depth averaged suspended sediment 

concentrations. In this case, the near bed sediment 

concentration is described as: 

c 

 

 

P 

 

e 

c 1 

1.25 

4.75p 

b 

 

2. 5 

d 

where P e is the Peclet number: 

 

 

 

 

ws 

h 

Pe 

 

Dz 

where h is the water depth, D z is the eddy 

diffusivity, both computed by the hydrodynamic 

model. 

Where E is the erodibility (kg m -2 s -1 ), n is the 

power of erosion, b is the bed shear stress (N m -2 ) 

and ce is the critical shear stress for erosion 

(N m -2 ). S E is the erosion rate (kg m -2 s -1 ). 

Soft bed 

For a soft, partly consolidated bed the erosion rate 

can be written as (Parchure and Mehta, 1985): 

 

 

 

b 

 

c 

S E e 

E 

 

b 

c 

 

 

 

 

 

 

Consolidation 

When long term simulations are performed 

consolidation of deposited sediment may be an 

important process. If several bed layers are used a 

transition rate (T i ) can be applied. This will cause 

sediment from the top layers to be transferred to 

the subsequently lower layers. 

Solution Technique 

The solution of the transport equations is closely 

linked to the solution of the hydrodynamic 

conditions. 

The spatial discretisation of the primitive 


volume method. The spatial domain is discretised 

by subdivision of the continuum into nonoverlapping 

elements/cells. In the horizontal plane 

an unstructured grid is used while in the vertical 

domain in the 3D model a structured mesh is used. 

In the 2D model the elements can be triangles or 

quadrilateral elements. In the 3D model the 

elements can be prisms or bricks whose horizontal 

faces are triangles and quadrilateral elements, 

respectively. 

The time integration is performed using an explicit 

scheme. 

Erosion 

Erosion features the following two modes. 

Hard bed 

For a consolidated bed the erosion rate can be 

written as (Partheniades, 1965): 

S 

E 

n 

 

E 

b 

 

 

1 

ce 

 

b 

c 

Page 4 




Computed bed shear stress 

Computed settling velocities 

Updated bathymetry 

Principle of 3D mesh 

Validation 

The model engine is well proven in numerous 

studies throughout the world: 

The MT module is a tool for estuary sediment 

management in complex estuaries like San Francisco bay, 

California, USA 

Model Input 

The generic nature of cohesive sediment dynamics 

reveals a numerical model that will always call for 

tremendous field work or calibration due to 

measurements performed. The following input 

parameters have to be given: 

Settling velocity 

Critical shear stress for erosion 

Critical shear stress for deposition 

Erosion coefficients 

Power of erosion 

Suspended sediment 

Concentration at open boundaries 

Dispersion coefficients 

Thickness of bed layers or estimate of total 

amount of active sediment in the system 

Transition coefficients between bed layers 

Dry density of bed layers 

Model Output 

The main output possibilities are listed below: 

Suspended sediment concentrations in space 

and time 

Sediment in bed layers given as masses or 

heights 

Net sedimentation rates 

The Rio Grande estuary, Brazil 

In 2001, the model was applied for a 3D study in 

the Rio Grande estuary (Brazil). The study 

focused on a number of hydrodynamic issues 

related to changing the Rio Grande Port layout. In 

addition the possible changes in sedimentation 

patterns and dredging requirements were 

investigated. 

SSC in surface layer (kg/m 3 ), Rio Grande, Brazil 





Graadyb tidal inlet (Skallingen), Denmark 

Instantaneous erosion (kg/m 2 /s), Rio Grande, Brazil 

The figure below shows the most common 

calibration parameter, which is the suspended 

sediment concentration (SSC). The results are 

reasonable given the large uncertainties connected 

with mud transport modelling. 

Bathymetry and computational mesh for the Graadyb tidal 

inlet, Denmark 

A comparison between measured and simulated 

SSC time series is shown below. The overall 

comparison is excellent. 

Suspended sediment concentrations, Rio Grande, Brazil 

The Graadyb tidal inlet, Denmark 

The MT module has also been used in the 

Graadyb tidal inlet located in the Danish part of 

the Wadden Sea. In this area, the highest tidal 

range reaches 1.7 m at springs, but the storm surge 

in the area can be as high as 2-4 metres. 

The maximum current in the navigation channel 

leading to the harbour of Esbjerg is in the range of 

1-2 m/s. The depth in the channel is 10-12 m at 

mean sea level. 

Comparison between measured and simulated suspended 

sediment concentrations, Graadyb tidal inlet, Denmark 

Page 6 




The graphical user interface of the MIKE 21 & MIKE 3 Flow Model FM MT module including an example of the Online Help 

System 

Graphical User Interface 

The MIKE 21 & MIKE 3 Flow Model FM, Mud 

Transport module is operated through a fully 

Windows integrated Graphical User Interface 

(GUI). Support is provided at each stage by an 

Online Help System. 

The common MIKE Zero shell provides entries 

for common data file editors, plotting facilities and 

utilities such as the Mesh Generator, the Data 

Viewer and the Data Manager. 

Overview of the common MIKE Zero utilities 





Parallelisation 

The computational engines of the MIKE 21/3 FM 

series are available in versions that have been 

parallelised using both shared memory (OpenMP) 

as well as distributed memory architecture (MPI). 

The result is much faster simulations on systems 

with many cores. 

MIKE 21/3 FM speed-up using multicore PCs for Release 

2011 with distributed memory architecture (blue) and 

shared memory architecture that was part of Release 2009 

(green) 

Hardware and Operating System 

Requirements 

The MIKE 21 and MIKE 3 Flow Model FM Mud 

Transport Module supports Microsoft Windows 

XP Professional Edition (32 and 64 bit), Microsoft 

Windows Vista Business (32 and 64 bit) and 

Microsoft Windows 7 Enterprise (32 and 64 bit). 

Microsoft Internet Explorer 6.0 (or higher) is 

required for network license management as well 

as for accessing the Online Help. 

The recommended minimum hardware 

requirements for executing MIKE 21 & MIKE 3 

Flow Model FM Mud Transport Module are: 

Processor: 

Memory (RAM): 

Hard disk: 

Monitor: 

Graphic card: 

Media: 

3 GHz PC (or higher) 



SVGA, resolution 1024x768 

32 MB RAM (or higher), 

32 bit true colour 

CD-ROM/DVD drive, 20 x 

speed (or higher) 

Support 

News about new features, applications, papers, 

updates, patches, etc. are available here: 

www.mikebydhi.com/Download/DocumentsAndTools.aspx 

For further information on MIKE 21 & MIKE 3 

Flow Model FM software, please contact your 

local DHI office or the Software Support Centre: 

MIKE by DHI 

DHI 

Agern Allé 5 


Denmark 

Tel: +45 4516 9333 

Fax: +45 4516 9292 



References 

Burt, N., 1986. Field settling velocities of estuary 

muds. In: Estuarine Cohesive Sediment Dynamics, 

edited by Mehta, A.J. Springer-Verlag, Berlin, 

Heidelberg, NewYork, Tokyo, 126–150. 

Krone, R.B., 1962. Flume Studies of the Transport 

of Sediment in Estuarine Shoaling Processes. 

Final Report to San Francisco District U. S. Army 

Corps of Engineers, Washington D.C. 

Mehta, A.J., Hayter, E.J., Parker, W.R., Krone, 

R.B. and Teeter, A.M., 1989. Cohesive sediment 

transport. I: Process description. Journal of 

Hydraulic Engineering – ASCE 115 (8), 1076– 

1093. 

Parchure, T.M. and Mehta, A.J., 1985. Erosion of 

soft cohesive sediment deposits. Journal of 

Hydraulic Engineering – ASCE 111 (10), 1308– 

1326. 

Partheniades, E., 1965. Erosion and deposition of 

cohesive soils. Journal of the hydraulics division 

Proceedings of the ASCE 91 (HY1), 105–139. 

Richardson, J.F and Zaki, W.N., 1954. 

Sedimentation and fluidization, Part I, 

Transactions of the institution Chemical Engineers 

32, 35–53. 

Teeter, A.M., 1986. Vertical transport in finegrained 

suspension and newly deposited sediment. 

In: Estuarine Cohesive Sediment Dynamics, edited 

by Mehta, A.J. Springer-Verlag, Berlin, 

Heidelberg, NewYork, Tokyo, 170–191. 

Page 8 




Teisson, C., 1991. Cohesive suspended sediment 

transport: feasibility and limitations of numerical 

modelling. Journal of Hydraulic Research 29 (6), 

755–769. 

Winterwerp, J.C. (1999) “Flocculation and settling 

velocity”, TU delft. pp 10-17. 

References on applications 

Edelvang, K., Lund-Hansen, L.C., Christiansen, 

C., Petersen, O.S., Uhrenholdt, T., Laima, M. and 

Berastegui, D.A., 2002. Modelling of suspended 

matter transport from the Oder River. Journal of 

Coastal Research 18 (1), 62–74. 

Lumborg, U., Andersen, T.J. and Pejrup, M., 

2006. The effect of Hydrobia ulvae and 

microphytobenthos on cohesive sediment 

dynamics on an intertidal mudflat described by 

means of numerical modelling. Estuarine, Coastal 

and Shelf Science 68 (1-2), 208–220. 

Lumborg, U. and Pejrup, M., 2005. Modelling of 

cohesive sediment transport in a tidal lagoon – An 

annual budget. Marine Geology 218 (1-4), 1–16. 

Petersen, O. and Vested, H.J., 2002. Description 

of vertical exchange processes in numerical mud 

transport modelling. In: Fine Sediment Dynamics 

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Date 01/2013 

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ESIA Albania Annex 9 - Sediment Dispersion Modelling

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