A Prediction Study Of Wave Propagation Before And After Tsunami In Ulee Lheue Coastal Waters, Aceh - Indonesia.pdf
International Symposium
Land Use after the Tsunami
Supporting Education, Research and Development
in the Aceh Region
Syiah Kuala University, Banda Aceh, Indonesia
November 4-6, 2008
Proceedings
Managing Board
Dr. T. Fadrial Karmil
Syiah Kuala University, Banda Aceh, Indonesia
Dr. Arifudin Bidin
Tadulako University, Palu, Indonesia
Prof. Walter Wenzel
University of Natural Resources and Applied Life Science, Vienna, Austria
Prof. Torsten Müller
Hohenheim University, Stuttgart, Germany
Prof. Eckhard George
Humboldt University, Institute of Vegetable and Ornamental Crops,
Berlin and Großbeeren, Germany
Dr. Laxman Joshi
World Agroforestry Centre Southeast Asia, Bogor, Indonesia
Edited by: Henrike Perner, Andrea George, Zaitun, Syahabuddin
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
A PREDICTION STUDY OF WAVE PROPAGATION BEFORE AND AFTER
TSUNAMI IN ULEE LHEUE COASTAL WATERS, ACEH, INDONESIA Setiawan,
I., Y. Ilhamsyah, E. Miswar and A. Haddrevi
Ichsan Setiawan1, Yopi Ilhamsyah1, Edy Miswar1 and Aykal Haddrevi1
Marine Sciences Department, Faculty of Mathematics and Natural Sciences, Syiah Kuala
Universit, Banda Aceh, Indonesia; ichsansetiawan@yahoo.com
Abstract
The prediction of wave propagation was done using wave numerical model for Ulee Lheue
coastal waters, Banda Aceh. The purpose of the present research is to predict the wave
propagation in Ulee Lheue coastal waters. The wind velocity and direction data for 2001
to 2006 were used to predict wave propagation before and after Tsunami. It is showed the
maximum height of wave is 0.33 m during wet season and 0.25 m in dry season.
Meanwhile, the maximum height after Tsunami is 1.50 m and 0.66 m during wet and dry
season.
Key words: Wave refraction, maximum height of wave before and after tsunami in Ulee
Lheue coastal waters
Introduction
Ulee Lheue coastal waters is situated in the northwest of Banda Aceh. It is a main sea
trade route from Ulee Lheue port to Balohan Sabang port. Erosion and Sedimentation are
major recent problems in this region, mostly caused by the wave striking upon the coast.
Thereby, a forecast research of wave propagation which in advance results in wave height
distribution is essential to carry out.
Material and Methods
The simulation of wave propagation was done by means of wave numerical model (Figure
1). Such incident wave data as height, angle and period were predicted using formulas
taken from US Army Corps of Engineers, 2006. In addition, such initial data of wind as
velocity and direction are taken from Agency of Meteorology and Geophysics (BMG) for
2001 - November 2004 and 2005-2006 for both pre-Tsunami and post-Tsunami data,
respectively. In the meantime, the equation taken from US Army Corps of Engineers, 1984
was used to calculate wind Fetch. Pre-Tsunami bathymetry data are acquired from Agency
of Hydro-Oceanography (Dishidros), 2001 (Figure 2). Meanwhile, Post-Tsunami
bathymetry data are acquired from Departemen Pekerjaan Umum Dinas Sumber Daya
Perairan Provinsi NAD for 2005 (Figure 3). Both data were used as the initial input in the
model. The numerical solutions are derived from wave equation taken from van Rijn, 1990
and Koutitas, 1984. On the other hand, equation H = H 0 K s K r was then used to calculate
wave height (Dean, 1984).
249
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
Model is run based on the following flowchart shown below:
1
START
The calculation of x-y orthogonal wave
The equation used are as follows:
θ n +1 + θ n
x n +1 = x n + ∆s. cos
2
n +1
n
θ +θ
y n +1 = y n + ∆s. sin
2
Bathimetry input (depth)
Wind input
The calculation of shoaling coefficient
The equation used are as follows:
Calculation of Fetch, Fetch =
1
Ks =
+
kd
kd
kd
1
2
sinh
2
tanh
)
(
∑ Li cos α i
∑ cos α
H 0 = 4.13 × 10
u ∗2
g
u
T = 0.751 ∗
g
gX
2
u∗
gX
2
u∗
pt = −
[
kh = y 0.5 1 + 0.166 y + 0.031y 2
y = 4.02
∂c
∂c
cos θ + sin θ
∂x
∂y
∂ 2c 2
∂ 2c
∂ 2c
qt = c
sin θ −
sin 2θ +
cos 2 θ
∂
∂
∂
∂
x
x
y
y
Kr =
1
β
Wave height calculation H
The equation used are as follows:
]
H = H0KS KR
h
T2
The determination of orthogonal wave
direction with wave refraction equation
The equation used are as follows:
sin θ n ∂c n cos θ n ∂c n
−
n
∂x
∂
cn
c
θ n +1 − θ n = ∆s
[sinh kd cosh kd + kd ]
∂ 2 β 1 ∂β
+ pt
+ qt β = 0
∂t 2 2
∂t
1/ 2
g
tanh(kh)
k
cosh kd
The calculation of refraction coefficient
The equation used are as follows:
Calculation of speed of wave
propagation
The equation used are as follows:
c=
=
i
Calculation of H0, T, α0 with wind input:
−2
12
Results:
(x,y) reference of orthogonal wave
Wave height distribution
END
1
Fig. 1: Flowchart
250
12
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
1
N
2
3
Fig. 2: The digitized pre-Tsunami Bathymetri data (m) according to Agency of HydroOceanography (Dishidros), 2001. 1). Ulee Lheue port 2). Main road to Banda Aceh. 3).
Main road to Lho’nga.
1
N
2
3
Fig. 3: The digitized pre-Tsunami Bathymetri data (m) according to Departemen
Pekerjaan Umum Dinas Sumber Daya Perairan Provinsi NAD. 1). Ulee Lheue port 2).
Main road to Banda Aceh. 3). Main road to Lho’nga.
Results and Discussion
The simulation of wave propagation
Figure 4 showed the propagation of wave for wet and dry season before and after
Tsunami. The propagation eventually brings about the divergence and convergence zone.
The latter occurred in cape where energy is greater than in bay (divergence zone). ErosionSedimentation are depicted by wave energy representing the formation of sedimentation in
divergence zone where orthogonal wave spread in this area whereas erosion occurred in
the convergence zone on the contrary.
251
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
a).
b).
c).
d).
Fig. 4: Wave propagation in Ulee Lheue waters for a). wet season before Tsunami, b). dry
season before Tsunami, c). wet season after Tsunami, and d). dry season after
Tsunami. 1). Convergence zone 2). Divergence zone.
Wave Height Distribution
Wave height distributions in the research before and after Tsunami are 0.33 m and 0.25 for
wet and dry season. Meanwhile, after Tsunami they reach 1.5 m and 0.66 for wet and dry
season. In addition, wave height breaks and decreases when it comes unto the coastal
zone.
252
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
050 35’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 18’ 00”
050 35’ 00” LU, 950 18’ 00”
N
050 33’ 00” LU, 950 15’ 30”
N
a.)
050 33’ 00” LU, 950 18’ 00”
050 35’ 00” LU, 950 15’ 30” BT
050 35’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 15’ 30” BT
050 35’ 00” LU, 950 18’ 00” BT
N
050 33’ 00” LU, 950 15’ 30” BT
b).
050 33’ 00” LU, 950 18’ 00”
N
050 33’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 15’ 30” BT
d).
c).
Fig. 5: The wave height distributions for a). scenario for wet season before Tsunami (m)
b). scenario for dry season before Tsunami (m), c). scenario for wet season after
Tsunami (m) and d). scenario for dry season after Tsunami (m).
Conclusions
From the results above, it can be concluded that:
1. The maximum height of wave propagation before Tsunami for wet and dry season are
0.33 and 0.25 m.
2. The maximum height of wave propagation after Tsunami for wet and dry season are
1.5 and 0.66 m.
3. The simulation of wave propagation is helpful in locating sedimentation and erosion
zone.
Acknowledgments
The author wished to express the gratitude to Prof. Dr. Syamsul Rizal for kindly supervise
and assist during the research, and at last but least to all my colleagues for kindly critical,
suggestion and support during the research.
References
1. Dean, R. and Dalrymple, R., (1984), “Water Wave Mechanics for Engineers and
Scientist”, Prentice Hall Press.
2. Koutitas, C. G., (1988) “Mathematical Models in Coastal Engineering”, Pentech Press
Limited, London.
253
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
3. U.S Army Coastal Engineering Research Center, (1984), “Shore Protection Manual
Volume I”, Department Of The Army Corps Of Engineering, Washington D.C, USA
4. U.S
Army Coastal Engineering Research Center, (2006), “Coastal
EngineeringManual”, Department Of The Army Corps Of Engineering, Washington
D.C, USA
5. van Rijn,L.C., (1990), “Principles of Fluid Flow and Surface Waves in Rivers,
Estuaries, Seas, and Oceans”, University of Utrecht, Department of Physical
Geography.
254
Land Use after the Tsunami
Supporting Education, Research and Development
in the Aceh Region
Syiah Kuala University, Banda Aceh, Indonesia
November 4-6, 2008
Proceedings
Managing Board
Dr. T. Fadrial Karmil
Syiah Kuala University, Banda Aceh, Indonesia
Dr. Arifudin Bidin
Tadulako University, Palu, Indonesia
Prof. Walter Wenzel
University of Natural Resources and Applied Life Science, Vienna, Austria
Prof. Torsten Müller
Hohenheim University, Stuttgart, Germany
Prof. Eckhard George
Humboldt University, Institute of Vegetable and Ornamental Crops,
Berlin and Großbeeren, Germany
Dr. Laxman Joshi
World Agroforestry Centre Southeast Asia, Bogor, Indonesia
Edited by: Henrike Perner, Andrea George, Zaitun, Syahabuddin
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
A PREDICTION STUDY OF WAVE PROPAGATION BEFORE AND AFTER
TSUNAMI IN ULEE LHEUE COASTAL WATERS, ACEH, INDONESIA Setiawan,
I., Y. Ilhamsyah, E. Miswar and A. Haddrevi
Ichsan Setiawan1, Yopi Ilhamsyah1, Edy Miswar1 and Aykal Haddrevi1
Marine Sciences Department, Faculty of Mathematics and Natural Sciences, Syiah Kuala
Universit, Banda Aceh, Indonesia; ichsansetiawan@yahoo.com
Abstract
The prediction of wave propagation was done using wave numerical model for Ulee Lheue
coastal waters, Banda Aceh. The purpose of the present research is to predict the wave
propagation in Ulee Lheue coastal waters. The wind velocity and direction data for 2001
to 2006 were used to predict wave propagation before and after Tsunami. It is showed the
maximum height of wave is 0.33 m during wet season and 0.25 m in dry season.
Meanwhile, the maximum height after Tsunami is 1.50 m and 0.66 m during wet and dry
season.
Key words: Wave refraction, maximum height of wave before and after tsunami in Ulee
Lheue coastal waters
Introduction
Ulee Lheue coastal waters is situated in the northwest of Banda Aceh. It is a main sea
trade route from Ulee Lheue port to Balohan Sabang port. Erosion and Sedimentation are
major recent problems in this region, mostly caused by the wave striking upon the coast.
Thereby, a forecast research of wave propagation which in advance results in wave height
distribution is essential to carry out.
Material and Methods
The simulation of wave propagation was done by means of wave numerical model (Figure
1). Such incident wave data as height, angle and period were predicted using formulas
taken from US Army Corps of Engineers, 2006. In addition, such initial data of wind as
velocity and direction are taken from Agency of Meteorology and Geophysics (BMG) for
2001 - November 2004 and 2005-2006 for both pre-Tsunami and post-Tsunami data,
respectively. In the meantime, the equation taken from US Army Corps of Engineers, 1984
was used to calculate wind Fetch. Pre-Tsunami bathymetry data are acquired from Agency
of Hydro-Oceanography (Dishidros), 2001 (Figure 2). Meanwhile, Post-Tsunami
bathymetry data are acquired from Departemen Pekerjaan Umum Dinas Sumber Daya
Perairan Provinsi NAD for 2005 (Figure 3). Both data were used as the initial input in the
model. The numerical solutions are derived from wave equation taken from van Rijn, 1990
and Koutitas, 1984. On the other hand, equation H = H 0 K s K r was then used to calculate
wave height (Dean, 1984).
249
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
Model is run based on the following flowchart shown below:
1
START
The calculation of x-y orthogonal wave
The equation used are as follows:
θ n +1 + θ n
x n +1 = x n + ∆s. cos
2
n +1
n
θ +θ
y n +1 = y n + ∆s. sin
2
Bathimetry input (depth)
Wind input
The calculation of shoaling coefficient
The equation used are as follows:
Calculation of Fetch, Fetch =
1
Ks =
+
kd
kd
kd
1
2
sinh
2
tanh
)
(
∑ Li cos α i
∑ cos α
H 0 = 4.13 × 10
u ∗2
g
u
T = 0.751 ∗
g
gX
2
u∗
gX
2
u∗
pt = −
[
kh = y 0.5 1 + 0.166 y + 0.031y 2
y = 4.02
∂c
∂c
cos θ + sin θ
∂x
∂y
∂ 2c 2
∂ 2c
∂ 2c
qt = c
sin θ −
sin 2θ +
cos 2 θ
∂
∂
∂
∂
x
x
y
y
Kr =
1
β
Wave height calculation H
The equation used are as follows:
]
H = H0KS KR
h
T2
The determination of orthogonal wave
direction with wave refraction equation
The equation used are as follows:
sin θ n ∂c n cos θ n ∂c n
−
n
∂x
∂
cn
c
θ n +1 − θ n = ∆s
[sinh kd cosh kd + kd ]
∂ 2 β 1 ∂β
+ pt
+ qt β = 0
∂t 2 2
∂t
1/ 2
g
tanh(kh)
k
cosh kd
The calculation of refraction coefficient
The equation used are as follows:
Calculation of speed of wave
propagation
The equation used are as follows:
c=
=
i
Calculation of H0, T, α0 with wind input:
−2
12
Results:
(x,y) reference of orthogonal wave
Wave height distribution
END
1
Fig. 1: Flowchart
250
12
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
1
N
2
3
Fig. 2: The digitized pre-Tsunami Bathymetri data (m) according to Agency of HydroOceanography (Dishidros), 2001. 1). Ulee Lheue port 2). Main road to Banda Aceh. 3).
Main road to Lho’nga.
1
N
2
3
Fig. 3: The digitized pre-Tsunami Bathymetri data (m) according to Departemen
Pekerjaan Umum Dinas Sumber Daya Perairan Provinsi NAD. 1). Ulee Lheue port 2).
Main road to Banda Aceh. 3). Main road to Lho’nga.
Results and Discussion
The simulation of wave propagation
Figure 4 showed the propagation of wave for wet and dry season before and after
Tsunami. The propagation eventually brings about the divergence and convergence zone.
The latter occurred in cape where energy is greater than in bay (divergence zone). ErosionSedimentation are depicted by wave energy representing the formation of sedimentation in
divergence zone where orthogonal wave spread in this area whereas erosion occurred in
the convergence zone on the contrary.
251
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
a).
b).
c).
d).
Fig. 4: Wave propagation in Ulee Lheue waters for a). wet season before Tsunami, b). dry
season before Tsunami, c). wet season after Tsunami, and d). dry season after
Tsunami. 1). Convergence zone 2). Divergence zone.
Wave Height Distribution
Wave height distributions in the research before and after Tsunami are 0.33 m and 0.25 for
wet and dry season. Meanwhile, after Tsunami they reach 1.5 m and 0.66 for wet and dry
season. In addition, wave height breaks and decreases when it comes unto the coastal
zone.
252
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
050 35’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 18’ 00”
050 35’ 00” LU, 950 18’ 00”
N
050 33’ 00” LU, 950 15’ 30”
N
a.)
050 33’ 00” LU, 950 18’ 00”
050 35’ 00” LU, 950 15’ 30” BT
050 35’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 15’ 30”
050 35’ 00” LU, 950 15’ 30” BT
050 35’ 00” LU, 950 18’ 00” BT
N
050 33’ 00” LU, 950 15’ 30” BT
b).
050 33’ 00” LU, 950 18’ 00”
N
050 33’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 18’ 00” BT
050 33’ 00” LU, 950 15’ 30” BT
d).
c).
Fig. 5: The wave height distributions for a). scenario for wet season before Tsunami (m)
b). scenario for dry season before Tsunami (m), c). scenario for wet season after
Tsunami (m) and d). scenario for dry season after Tsunami (m).
Conclusions
From the results above, it can be concluded that:
1. The maximum height of wave propagation before Tsunami for wet and dry season are
0.33 and 0.25 m.
2. The maximum height of wave propagation after Tsunami for wet and dry season are
1.5 and 0.66 m.
3. The simulation of wave propagation is helpful in locating sedimentation and erosion
zone.
Acknowledgments
The author wished to express the gratitude to Prof. Dr. Syamsul Rizal for kindly supervise
and assist during the research, and at last but least to all my colleagues for kindly critical,
suggestion and support during the research.
References
1. Dean, R. and Dalrymple, R., (1984), “Water Wave Mechanics for Engineers and
Scientist”, Prentice Hall Press.
2. Koutitas, C. G., (1988) “Mathematical Models in Coastal Engineering”, Pentech Press
Limited, London.
253
Poster
International Symposium
Land Use after the Tsunami – Supporting Education, Research and Development in the Aceh Region
November 4-6, 2008
3. U.S Army Coastal Engineering Research Center, (1984), “Shore Protection Manual
Volume I”, Department Of The Army Corps Of Engineering, Washington D.C, USA
4. U.S
Army Coastal Engineering Research Center, (2006), “Coastal
EngineeringManual”, Department Of The Army Corps Of Engineering, Washington
D.C, USA
5. van Rijn,L.C., (1990), “Principles of Fluid Flow and Surface Waves in Rivers,
Estuaries, Seas, and Oceans”, University of Utrecht, Department of Physical
Geography.
254