storm surge prediction in vietnam -...

Storm Surge Prediction in Vietnam

By: Nguyen Ba Thuy1, Lars R. Hole2, Nils Melsom Kristensen2, Johannes

Röhrs2 and Pham Khanh Ngoc1

1VietnamNational Center for Hydro-meteorological Forecasting (NCHMF) 2Norwegian Meteorological Institute (MetNo)

Contents

1. Typhoon and storm surge in Vietnam

2. Storm surge prediction – Application ROMS Model

3. Future work

Large and Complicate Tide

Typhoon (June-November)

North- East Monsoon (November-March)

South - East Monsoon (June-October)

Geographic and climate effect

Typhoon in Vietnam

- There are about 10-12

typhoons and 5-6 affect

to land.

Storm distribution in South China Sea

Storm numbers monthly attacking

Vietnam coast in 53 years

Typhoon and storm surge in Vietnam

Track of typhoon in 2013

Total: 13 typhoons

Strong Haiyan typhoon

Land fall the coast at

Vietnam at low tide

- No inundation

Pressure variation

Track

Damage due to typhoon

Both Typhoon No 10 and11

(2013): 25 people die, loss

1800 billions VND ( 90 million

USD)

7 death and 43 injury during

Sonting (2012) typhoon affect,

with maximum wind speed up

to 47m/s, central pressure of

945 hPa. Loss 75000 billion

VND (375 million USD)

Television tower was collapsed by high wind force

Honla breakwater was broken by high wave (up to 5m)


Inundation due to high tide and heavy rain at Doson in Typhoon No4


High Vulnerable storm surge

(abundant typhoon +

shallow water)

Less Vulnerable storm surge

(rare typhoon + deep water)

Less Vulnerable storm surge

(shallow water +rare typhoon)

Number of

Typhoon

Typhoon and storm surge in Vietnam

Storms and surges along Vietnam coast

Storm surge in Vietnam coastal

storm surge in 2013

Typhoon No 2 (land fall at high tide,

surge height: 0.7m-inundation Typhoon No 10-Wutip (strong-Surge height:

1.3m at low tide)

Typhoon No 11-Nari (strong-Surge height: 1.5m at low tide)

In 2013: 13 typhoons.

Three generated hight

surge on coast

Two dimensional long wave equations + Swan model

SuWAT (Surge Wave and Tide) Model-Operational Model

Open bounday condition: NAO.99b, NAO.99Jb models-

http://www.miz.nao.ac.jp/staffs/nao99/README_NAOTI

DE_En.html).

Effect of

tide and

wave are

considered

Storm surge prediction in Vietnam

http://www.miz.nao.ac.jp/staffs/nao99/README_NAOTIDE_En.html
















- Wind and Pressure Model:

+ Typhoon Model: Empirical model

2

0)/(1

)(rr

PPPrP c

(Fujita)

Storm surge prediction in Vietnam

50021 )sinsincos(cos

)sincoscos(sin r

ty

tx

g

g

y

xe

v

vc

V

Vc

v

vV

+ NWP: WRF

Structure of SuWAT Model in Vietnam

D1 D2

D3

-1.5

-1

-0.5

0

0.5

1

1.5

4/1/2014 0:00 4/6/2014 0:00 4/11/2014 0:00 4/16/2014 0:00 4/21/2014 0:00 4/26/2014 0:00 5/1/2014 0:00

Time (h)

Tid

e e

levation (

m)

Harmonic Analyze

ModelCua Hoi Station

-1.5

-1

-0.5

0

0.5

1

1.5

4/1/2014 0:00 4/6/2014 0:00 4/11/2014 0:00 4/16/2014 0:00 4/21/2014 0:00 4/26/2014 0:00 5/1/2014 0:00

Time (h)

Tid

e e

levati

on

(m

)

Harmonic Analyze

ModelHondau Station

-1

-0.5

0

0.5

1

4/2/2014 0:00 4/7/2014 0:00 4/12/2014 0:00 4/17/2014 0:00 4/22/2014 0:00 4/27/2014 0:00 5/2/2014 0:00

Time (s)

Tid

e e

leva

tio

n (

m)

Harmonic Analyze

ModelDa Nang Station

-1

-0.5

0

0.5

1

4/1/2014 0:00 4/6/2014 0:00 4/11/2014 0:00 4/16/2014 0:00 4/21/2014 0:00 4/26/2014 0:00 5/1/2014 0:00

Time (h)T

ide

ele

va

tio

n (

m)

Harmonic Analyze

Model

Quy Nhon Station

-1

-0.5

0

0.5

1

4/1/2014 0:00 4/6/2014 0:00 4/11/2014 0:00 4/16/2014 0:00 4/21/2014 0:00 4/26/2014 0:00 5/1/2014 0:00

Time (h)

Tid

e e

levation (

m)

Harmonic Analyze

ModelNha Trang Station

Vunngtau

Verifying the SuWAT Model

on Tide on April 2014

Variation of storm surge at Danang Station

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

9/28/2006 19:12 9/29/2006 19:12 9/30/2006 19:12 10/1/2006 19:12

Thời gian (giờ)N

ướ

c d

âng

(m

)

Quan trắc

Không thủy triều và sóng

Có thủy triều-không sóng

Không có thủy triều-có sóng

Có thủy triều và sóng

Nước dâng

do sóng

OBS

Surge only

Surge+tide

Surge+wave

Surge+tide+wave Surge

height

(m)

Time(hour)

Wave

setup

Effect of tide is insignificant, but wave

significant

Effect of wave on Storm surge

Track of Xangsena typhoon ( 9/2006)

land fall at Danang (middle of

Vietnam)

Maximum storm surge

(a) (b) (a) Without consider wave (b) With wave

Effect of tide and storm surge on wave height

(a) Without consider wave (b) With wave

Maximum significant wave height


-2

0

2

4

6

8

10

9/29/2006 0:00 9/29/2006 19:12 9/30/2006 14:24 10/1/2006 9:36

Thời gian (giờ)

Độ c

ao (

m)

Hsig - Trên nền mực nước trung bình

Hsig. - Trên nền thủy triều và nước dâng do bão

Mực nước

Vị trí gần bờ H=6.5m

H=30m

-2

0

2

4

6

8

10

9/29/2006 0:00 9/29/2006 19:12 9/30/2006 14:24 10/1/2006 9:36

Thời gian (giờ)

Độ c

ao (

m)

Hsig - Trên nền mực nước trung bình

Hsig. - Trên nền thủy triều và nước dâng do bão

Vị trí xa bờ

(b)

Hig.- without tide and storm surge

Hsig.-With tide and storm surge

Water level

Hig.- without tide and storm surge

Hsig.-With tide and storm surge

D=4.5m D=30.5m

Time (hour) Time (hour)

Height

(m)

Height

(m)


Time variation of Hsig. at shallow and deep water point

- Model setup by: Norwegian

Meteorological Institute under

the project “Strengthen the early

warning system” at National

Centre for Hydrometeorological

Forecasting of Vietnam

(NCHMF)

-Meteorological Model:

+ WRF

+ Resolution: 15km.

+ Boundary: GSM-JMA GFS-

NCEP

ROMS Model - Under research

Computational domain and bathymetry

Some Preliminary Results



Vietnam)

Case 1: Xangxane typhoon 2006

Wind and pressure at the time

typhoon land fall –WRF model

Distribution of surge height at the time typhoon Xangxane (9/2009)

land fall – ROMS Mode Results

Time Variation of Storm Surge at

Cuviet (above) and Danang (below)

Stations

Cuviet: river station

Danang: Sea station

Verifying the model with OBS

data for typhoon Xangxane

(9/2006)

-0.5

0

0.5

1

1.5

2

2006/09/29 00:00 2006/09/30 00:00 2006/10/01 00:00 2006/10/02 00:00

Time (hour)

Surg

e hei

ght

(m)

OBS

SuWAT

ROMS

-0.5

0

0.5

1

1.5

2

9/29/06 0:00 9/30/06 0:00 10/1/06 0:00 10/2/06 0:00

Time (hour)

Su

rge

hei

gh

t (m

)

OBS

SuWAT

ROMS

Flooding due

heavy rain

Track of Ketsena typhoon ( 9/2009)


Vietnam)

Case 2: Ketsena typhoon (9/2009)

Wind and pressure at the time

typhoon land fall –WRF model

Distribution of surge height at the time typhoon Xangxane

(9/2006) land fall -ROMS Mode Results

Time Variation of Storm Surge at

Cuaviet (above) and Danang

(below) Stations

-0.5

0

0.5

1

1.5

2

2.5

9/25/2009

0:00

9/26/2009

12:00

9/28/2009

0:00

9/29/2009

12:00

10/1/2009

0:00

10/2/2009

12:00

Time (hour)

Su

rge

hei

gh

t (m

)

OBS

ROMS

Verifying the model with OBS

data for typhoon Ketsena

(9/2009)

In this case: SuWAT using

Empirical typhoon Model

(Fujita Model)

-0.5

0

0.5

1

1.5

2

2009/09/27

00:00

2009/09/28

00:00

2009/09/29

00:00

2009/09/30

00:00

2009/10/01

00:00

Time (hour)S

urg

e hei

ght

(m)

OBS

SuWAT

ROMS

-50

0

50

100

150

200

250

300

350

400

450

9/16/2014

9:36

9/16/2014

14:24

9/16/2014

19:12

9/17/2014

0:00

9/17/2014

4:48

9/17/2014

9:36

9/17/2014

14:24

9/17/2014

19:12

9/18/2014

0:00

9/18/2014

4:48

9/18/2014

9:36

9/18/2014

14:24

Time (h)

H (

cm)

Total water level

Tide

Surge

Time of typhoon land fall

time of storm

surge exceed

0.5m

Case 3: Kalmaegi typhoon 2014



Vietnam)

Time Variation of total level, tide

and Surge at Hondau Station

The surge generated after typhoon

landfall and reached to 12 hours (look

right figure). This is due to South-West

monsoon.

Suge and wave after typhoon Kalmaegi Land fall 12 hour

Surge + high tide + wave generated

inundation at Haiphong coast

Distribution of surge height at the time Kalmaegi typhoon

9/2014 land fall 3 and 6 hour - ROMS Mode Results.

Time Variation of Storm surge at Hondau Station

Verifying the model with OBS data for

typhoon Kalmaegi (9/2014)

-1

-0.5

0

0.5

1

1.5

2

9/16/2014 0:00 9/16/2014 18:00 9/17/2014 12:00 9/18/2014 6:00 9/19/2014 0:00

Time (hour)

Su

rge

hei

ght

(m)

OBS

SuWAT- WRF

SuWAT-Fujita

ROMS

0

5

10

15

20

25

9/15/2014 0:00 9/16/2014 0:00 9/17/2014 0:00 9/18/2014 0:00

Time (hour)

Win

d v

elo

city

(m

/s)

OBS

Fujita

WRF

980

985

990

995

1000

1005

1010

1015

9/14/2014 12:00 9/15/2014 12:00 9/16/2014 12:00 9/17/2014 12:00

Time (hour)

Pre

ssu

re (

hp

a)

OBS

Fujita

WRF

Time variation at Hondau station during typhoon Kalmaegi

(9/2014)

Conclusion and future work

1. ROMS model can simulate good agreement surge not only

in the case of typhoon, but strong wind.

2. Operation surge in monsoon (wind and airpressure

variation)

3. Coastal inundation due to storm tide.

4. Asiimilation for HF radar (wave and surface current)

Surface ccean current in South China sea and the coast of

Vietnam – Result from observation and analyze

- Strong surface current in SW direction

In winter (Dec.-Jan.) In summer (Jun-Aug.)

- Strong surface current in NE direction

Upwelling in SW monsoon

Observation station for investigation upwelling

Upwelling

zone

Thank You - Questions and Discussion?

storm surge prediction in vietnam -...

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