Chapter III
Numerical Modeling
44
III.5.2. Results interpretation
2-Year Return Period
The results obtained for the 2-year return period are presented in Table III-7 and Figure III-6.
Offshore waves in the Bay retain more than 95% of their initial height of 4.64 m at the model
boundaries due to the deep water near the Bay of Algiers. The seabed does not affect the waves
significantly.
As the waves enter the bay, their characteristics (height and initial power of 83 KW/m) gradually
decrease due to the underwater morphology of the bay, which is characterized by reduced depth.
The waves are slowed down by the seabed, undergo significant deviation through diffraction and
refraction when encountering obstacles, resulting in a progressive loss of energy.
All waves approach the structure with a north direction in the marina and a North-Northeast
direction in the port, influenced by orthogonal lines perpendicular to the isobaths.
On the marina side, Cape Matifou provides direct protection to the area. Additionally, due to the
underwater topography, the waves reaching the base of the structure have a height of
approximately 2.22 m, with a shoaling coefficient of 0.48, indicating a loss about half of their
intensity.
On the port side, Cape Matifou does not offer any protection to the area. Waves from this
direction attack the port obliquely, resulting in higher wave heights at the jetties compared to the
marina. These waves have a height of approximately 3.54 m, with a shoaling coefficient of about
0.48, indicating a loss of only 17% of their initial energy.
The currents in the area, generated by winds and waves from the North-Northeast direction, flow
East-West along the coast with an average speed of about 0.33 m/s. The incident wave direction
plays a significant role in generating currents in shallow areas near the coast.
In conclusion, the wave simulation for the 2-year return period, considering the most challenging
direction, demonstrates that the marina remains protected against wave and current impacts.
Although wave diffraction on the breakwater is observed, the marina's protection is maintained;
unlike the Port which is quite exposed to wave attacks of this direction.
10-Year Return Period
The results obtained for the 10-year return period are presented in Table III-7and Figure III-7.
According to the results, offshore waves in the Bay retain over 93% of their initial height of 5.81
m at the model boundaries.
As the waves enter the bay, their hydrodynamic characteristics, such as height and initial power
of 170 KW/m, gradually decrease due to friction with the seabed, which slows down the wave
and causes deviation through diffraction and refraction when encountering obstacles, leading to a
progressive loss of energy.
Numerical Modeling
44
III.5.2. Results interpretation
2-Year Return Period
The results obtained for the 2-year return period are presented in Table III-7 and Figure III-6.
Offshore waves in the Bay retain more than 95% of their initial height of 4.64 m at the model
boundaries due to the deep water near the Bay of Algiers. The seabed does not affect the waves
significantly.
As the waves enter the bay, their characteristics (height and initial power of 83 KW/m) gradually
decrease due to the underwater morphology of the bay, which is characterized by reduced depth.
The waves are slowed down by the seabed, undergo significant deviation through diffraction and
refraction when encountering obstacles, resulting in a progressive loss of energy.
All waves approach the structure with a north direction in the marina and a North-Northeast
direction in the port, influenced by orthogonal lines perpendicular to the isobaths.
On the marina side, Cape Matifou provides direct protection to the area. Additionally, due to the
underwater topography, the waves reaching the base of the structure have a height of
approximately 2.22 m, with a shoaling coefficient of 0.48, indicating a loss about half of their
intensity.
On the port side, Cape Matifou does not offer any protection to the area. Waves from this
direction attack the port obliquely, resulting in higher wave heights at the jetties compared to the
marina. These waves have a height of approximately 3.54 m, with a shoaling coefficient of about
0.48, indicating a loss of only 17% of their initial energy.
The currents in the area, generated by winds and waves from the North-Northeast direction, flow
East-West along the coast with an average speed of about 0.33 m/s. The incident wave direction
plays a significant role in generating currents in shallow areas near the coast.
In conclusion, the wave simulation for the 2-year return period, considering the most challenging
direction, demonstrates that the marina remains protected against wave and current impacts.
Although wave diffraction on the breakwater is observed, the marina's protection is maintained;
unlike the Port which is quite exposed to wave attacks of this direction.
10-Year Return Period
The results obtained for the 10-year return period are presented in Table III-7and Figure III-7.
According to the results, offshore waves in the Bay retain over 93% of their initial height of 5.81
m at the model boundaries.
As the waves enter the bay, their hydrodynamic characteristics, such as height and initial power
of 170 KW/m, gradually decrease due to friction with the seabed, which slows down the wave
and causes deviation through diffraction and refraction when encountering obstacles, leading to a
progressive loss of energy.