Impacts of Climate Change
on Malaysia Coastline
National Water Research Institute of Malaysia / Institut Penyelidikan Air Kebangsaan Malaysia
Sea Level Rise
National Water Research Institute of Malaysia / Institut Penyelidikan Air Kebangsaan Malaysia
PROJECTED SEA LEVEL RISE FROM 2020 TO 2100
• Observed tide gauge
shown the trend of
rising sea
• The projections were
based on IPCC Fifth
Assessment Report
AR5 (Representative
Concentration PathwayRCP)
Source: NAHRIM 2017
Link:
http://www.nahrim.gov.my/images/pengu
muman/CSIRO_Malaysia_SeaLevelRise
Report_FinalReport_2017.pdf
National Water Research Institute of Malaysia / Institut Penyelidikan Air Kebangsaan Malaysia
4
PROJECTED SEA LEVEL RISE RCP 8.5 @ 2100 Vs
Land Elevation Less Than 1m
Contour elevation < 1 m
Source: NAHRIM 2017
National Water Research Institute of Malaysia / Institut Penyelidikan Air Kebangsaan Malaysia
5
COASTAL FLOODING DUE TO SEA LEVEL RISE SCENARIO RCP 8.5
Ban tanah kawasan Kuala Muda (Nov. 3,
2021, bhnews@bh.com.my)
Anggaran panjang pantai yang berisiko kesan kenaikan aras laut
• Semenanjung Malaysia : 1,015 km
• Sabah : 1,160 km
• Sarawak : 700 km
Jumlah keseluruhan panjang pantai berisiko: 2,875 km
Kawasan banjir pantai
kesan RCP 8.5 @ tahun 2100
Cadangan kawasan ban
pantai (aras lindung selamat)
Lokasi gambar kawasan terjejas
Pekan Sibu dinaiki air limpahan Sg. Rajang
(Okt. 2021, suaras arawak.my)
Foto udara Jetty Minyak Beku
(NAHRIM, 2021)
Tebingan Kuching ditenggelami air Sg.
Sarawak
Jan. 2021 (www.astroawani.com)
Long Lama, Marudi di Sarawak (Malaysianow.com,
Bernama May 22, 2021)
Laluan di sekitar kawasan pekan Putatan dinaiki
air (www.borneotoday.net)
Storm Surge
National Water Research Institute of Malaysia / Institut Penyelidikan Air Kebangsaan Malaysia
OFFSHORE WAVE AT STRAIT OF MALACCA
WAVE ANALYSIS
Northeast Monsoon
Annual
Item
Seasonal
Wave Height
Analysis on extreme value over 10 years data
Inter Monsoon
Southwest Monsoon
Unit
Northeast
Monsoon
(NE)
Southwest
Monsoon (SW)
Wave height
m
0.8
1.1
Wave Period
s
4.5
5.2
Wave
Direction
°N
80 °N
270 °N
Significant Angle
Return
Period
[years]
60 DEG
90 DEG
210 DEG
240 DEG
270 DEG
300 DEG
Hs (m) Tp (s) Hs (m) Tp (s) Hs (m) Tp (s) Hs (m) Tp (s) Hs (m) Tp (s) Hs (m) Tp (s)
2
2.06
4.96
2.26
5.26
2.48
6.28
2.16
5.93
2.97
5.80
1.83
5.36
5
2.29
5.08
2.51
5.41
3.04
6.44
2.48
6.09
3.28
5.88
2.10
5.52
10
2.44
5.16
2.67
5.51
3.48
6.55
2.70
6.18
3.48
5.93
2.29
5.63
30
2.66
5.27
2.92
5.64
4.26
6.71
3.03
6.31
3.78
6.00
2.64
5.80
50
2.76
5.31
3.033
5.70
4.67
6.79
3.19
6.37
3.91
6.03
2.81
5.89
100
2.90
5.37
3.19
5.78
5.27
6.89
3.38
6.44
4.08
6.07
3.07
6.00
Annually %
increase
ARI
1-5 year
3.48
5-10 year
1.22
10 - 30 year
0.43
30 - 50 year
0.17
50 - 100 years
0.09
OFFSHORE WAVE AT SOUTH CHINA SEA
Unit
Northeast
Monsoon
(NE)
Southwest
Monsoon
(SW)
Wave
height
m
1.3
0.7
Wave
Period
s
4.8
4.1
Wave
Direction
°N
65 °N
165°N
Item
Wave
Analysis on extreme value over 10 years data
Significant Angle
Return Period [years]
2
5
10
30
50
31-60 DEG
Hs (m)
3.776
4.168
4.414
4.772
4.93
Tp (s)
5.96
6.11
6.21
6.33
6.38
61-90 DEG
Hs (m)
3.952
4.455
4.786
5.284
5.511
Tp (s)
6.14
6.28
6.37
6.49
6.54
151-180 DEG
Hs (m)
1.821
2.198
2.488
2.998
3.263
Tp (s)
4.61
4.72
4.79
4.89
4.94
181-210 DEG
Hs (m)
1.477
1.726
1.913
2.235
2.399
Tp (s)
4.53
4.64
4.72
4.84
4.90
ARI
1-5 year
5-10 year
10 - 30 year
30 - 50 year
Annually %
increase
4.24
1.49
0.52
0.21
Penang
ARI
270deg
2
2.97
5
3.28
10
3.48
30
3.78
50
3.91
100
4.08
A
Annually
10.43771 3.479237
6.097561 1.219512
8.62069 0.431034
3.439153 0.171958
4.347826 0.086957
Dominated Hs for Kedah and Penang
Hs (m)
A
3.952
4.455
4.786
5.284
5.511
Annually
12.72773 4.242578
7.429854 1.485971
10.40535 0.520267
4.295988 0.214799
• Hs at ARI 10yr= 4.786m
• Hs at ARI 5yr= 3.28m
• To get the % increase from ARI 2yrto ARI 5yr is
ARI 5yr = [Existing + increase %] * ARI 2yr
existing
A increase in (5 -2 yr)=3 years
3.28m = [(100+A)/100] * 2.97 m
A = [3.28/2.97]m*100- 100
A= 10.43% for 3 years; thus 1 year =3.48%
Note: referred to
2
5
10
30
50
61-90 DEG
Dominated Hs for Kelantan and Terengganu
• Hs at ARI 2yr= 2.97 m
3.28m = [(100+A)/100] * 2.97 m
Return Period
[years]
• Hs at ARI 30yr= 5.284m
• To get the % increase from ARI 10yrto ARI 30yr is
ARI 30yr = [existing + increase %] * ARI 10yr
5.284m = [(100+A)/100] * 4.786 m
existing
A increase in (30-10 yr)=20 years
A = [5.284/4.786]m*100- 100
A= 10.41% for 20 years; thus 1 year =0.52%
COMPARISON SIGNIFICANT WAVE HEIGHT (M)
Annually well calibrated SW model
Water depth at 10 m ACD
Coastal Structural Crest
Height Calculation
INITIAL COASTAL PROTECTION CREST LEVEL
No
ARI
MHWS
1
2020
2030
2050
2100
1.38
1.38
1.38
1.38
2
2020
2030
2050
2100
1.02
1.02
1.02
1.02
3
2020
2030
2050
2100
0.83
0.83
0.83
0.83
SLR
Hs @ ARI (Wave and wind set up) General Crest level @LSD
Kedah
0.07
1.61
3.06
0.11
1.77
3.26
0.22
1.95
3.55
0.68
2.14
4.20
Terengganu
0.07
3.60
4.69
0.11
3.96
5.09
0.23
4.36
5.61
0.7
4.79
6.51
Kota Kinabalu
0.07
2.33
3.23
0.12
2.56
3.51
0.25
2.82
3.90
0.73
3.10
4.66
% increase
1%
0.50%
0.20%
1%
0.50%
0.20%
1%
0.50%
0.20%
• Crest level = MHWS + Sea level rise + Wind set up + Wave Setup
Using the Hs at 10 m water depth (further research is on going
between DID and NAHRIM)
MHWS~ 1.02m
No
ARI
2
MHWS
2020
2030
2050
2100
1.02
1.02
1.02
1.02
Hs @ ARI (Wave and wind
SLR
set up)
Terengganu
0.07
3.60
0.11
3.96
0.23
4.36
0.7
4.79
General Crest level
@LSD
% increase
4.69
5.09
5.61
6.51
1%
0.50%
0.20%
• Crest height = MHWS + SLR +Wave setup + Wind setup
• Spectral wave (SW) using wind velocity components, with the coverage from the pacific ocean to
Andaman sea in the grid series data
• MHWS= 1.02m
• SLR referred to NAHRIM 2017
• HS at 10 m ACD~ 3 m (20% is added because the HS was based on 2002 to
2006 simulated result.
• Wave calibration used the time series continued wave measurement data at
Cherating in 2005 & 2006 by NAHRIM.
percentage
• Therefore Hs for year 2020= 3 m*120/100=3.6m
• Hsfor 2030 : assumed to increase 1% annually = [(existing+ (increase in number
of year )/100]*Hs for 2020
• Hsfor 2030 = [(100+ ((year 2030-2020) * 1)/100]*3.6m = 3.96 m
• Hsfor 2050 = [(100+ ((year 2050-2030) * 0.5)/100]*3.96m = 4.36 m
• Hsfor 2100 = [(100+ ((year 2100-2050) * 0.2)/100]*4.36m = 4.79m
• Crest level for 2050= 1.02m (MHWS) + 0.23m (SLR) + 4.36 m (Hs)= 5.61 m from the mean sea level
MHWS~ 1.02m
LAYOUT OF ROCK REVETMENT
LAYOUT OF ROCK REVETMENT
Results & Discussion
Adopted Design Approach
Table 3: Changes to Design Parameters and Design Output at
Terengganu Coast
• The differences in the design of
coastal rock revetment works are
compared to obtain the optimum
design
parameters
for
Kuala
Terengganu.
No.
Description
1
2
• The main design parameters and
design output that will be the main
focus of the comparison are the
Design Water Level, Design Wave
Height, Crest Level and Armour
Stone Size.
4
MSL (mCD*)
MHHW
/MHWS
(mCD*)
Design Water Level
(mCD*)
Design Wave Height
(m)
Crest Level (mCD*)
Crest Width (m)
Armour Size (tons)
• A sketch of the coastal revetment
design for the current condition and
the year 2100 condition is shown in
Figure 10.
3
5
6
7
Current
Condition (m)
1.45
2..67
Year 2100
(m)
1.75
2.97
Difference
3.49
3.79
0.30
4.77
4.79
0.02
7.89
5.00
12.10
8.20
5.05
12.40
0.31
0.05
0.30
0.30
0.30
Thanks