tsunami hazard and risk assessment and warning system for coastal areas of vietnam

Tsunami Hazard and Risk Assessment and Warning System for Coastal Areas of Vietnam

Institute of Geophysics/VAST, VietnamGNS Science, New Zealand

Dr Terry H. Webb , Professor Bui Cong Que, Dr Le Huy Minh, Dr My Thanh Tran Thi, Dr Nguyen Dinh Xuyen, Dr Ken R. Gledhill , and Dr Mark W. Stirling

Institute of Geophysics, VAST GNS Science

NZAID/ADAF Programme Goals

– To assist in strengthening the capacity of Vietnamese scientists to enable Vietnam to minimise the impact of tsunami disasters on coastal and offshore island communities so that risk can be assessed and mitigation strategies developed. (Objective 1)

– To strengthen the capacity of scientists at IGP in the development of an earthquake information and tsunami early warning system. (Objective 2)


Roadmap for a Probabilistic Tsunami Hazard & Risk Assessment

Hazard Source Identification- Local, Regional, Distant

Tsunami wave height at coast, with likelihood

(magnitude/frequency)

numerical modelling, historical data, empirical approach

Inundation empirical equations & GIS or hydrodynamic modelling

Loss/Risk Exposure, census data, casualty & infrastructure models

OutputLosses at specified return period (loss curve)

Is the level of risk acceptable?

• Natural and engineering mitigation• Land-use Planning• Effective early warning systems

earthquake, volcano, landslide

Tsunami Hazard Now Defined


Objective 1 – Tsunami hazard and risk assessment

Capacity building by training to date:– Introductory workshops, April 2007;

– Working session to define tsunami sources, August 2007;

– Training in New Zealand for 3 scientists, October 2007;

– Technical Review (at IGP/VAST, April 2008);

– Field campaign – Asset data collection, April 2008; and

– Training in New Zealand for 3 scientists, October 2008.


Objective 1 Tsunami Hazard and Risk Assessment – Nha Trang pilot

Capacity building by application – Ongoing

• Develop input for propagation model– Source catalogue development (2008)– Bathymetry model for propagation paths (2008)

• Community assets defined– Data collection & ground truth (April 2008)

• Building inventory • Population distribution• Local creation of asset inventory – GIS based (Sept 08)

– Development of roughness layer for inundation modelling (underway)


Current Training

Applied training at GNS Science for 3 IGP staff:

– Source definition confirmation

– Propagation modelling – Nha Trang

– Impact tables development – Nha Trang

• Inundation modelling

• Asset model quantification

– Risk application – principles and application


Philippines Subduction Source Preliminary Segmentation Model


Maximum Wave Heights for Full Subduction Source (Mw 9.2)


Nha TrangTopographyModel


Nha Trang Preliminary Inundation Model

Camfield algorithm implemented in GIS

6 m inundation depth at shore assumed


Building Block Definition and Assignment


Identifier Description % Building types Storey Comments

A1 Single building 100 Use = Tourist All Hotel, Hostel, Motel

A2 Single building 100 Use = Office All

A3 Single building 100 Use = Government Admin All

A4 Single building 100 Use = Education All School, preschool, University

A5 Single building 100 Use = Medical All Hospital, Clinic

A6 Single building 100 Use = Emergency All Police, Army, Ambulance,

B1 Residential 100 Type 1 Old timber weak poor construction

B2 Residential 100 Type 2 Old Masonry weak construction

B3 Residential 100 Type 4 Age≥3, Closed ground floor Modern single houses ≤ 4 storey

Building Block Definitions


Ground Truthing Building Type and Use


Identifier Name Mapper function Description

1 Weak timber or masonry Age<3, Mat=1 Old tin/stick construction

2 Brick (simple construction) Age<3, Mat=2 Older simple masonry buildings

3 Moderate strength timber or masonry Age>3, Mat=1 or 2 Post-1975 masonry or timber buildings

4 Reinforced concrete and brick Mat=3 Modern building form

Building Types


Image Name Street Name Street No.

No. of Floors

Basement (y/n)

Total Area (m2)

Use Height (m)

Ground Floor

Height (m)

1st Floor

Height (m)

Age class

Quality

Condition

People Day

People night

1Day02\C1\

P4130328.jpg

Biệt thự Sts 32 3 0 54shopping

and housing

0.2 5 5 1 1 6 5

2Day02\C1\

P4130329.jpg

Nguyễn Thiện Thụât 85 4 308

shopping and

housing12 0.2 5 5 1 1

3Day02\C1\

P4130330.jpg

Nguyễn Thiện Thụât 81 2 660

shopping and

housing9 0.2 4.5 4 2 2 25 20

4Day02\C1\

P4130336.jpg

Nguyễn Thiện Thụât 71 2 0 96

shopping and

housing8 0.15 4 4 2 2 30 15

Building Attribute Data


Pathway forward (Objective 1; 2009 1st quarter)

• Methodology for development of Tsunami Hazard Maps (‘Wave Height at Coast’)– 3–6 Coastal Zones– Interpolation for full coastal coverage

• For Nha Trang– Scenario propagation and inundation models applied– Probabilistic loss models developed– Tsunami risk evaluated


Objective 2 – Earthquake information and tsunami early warning system

• Review of Vietnet proposal;• Options for Operations Centre;• Study Tour to New Zealand;• IRIS training course in KL;• Attendance at Taiwan early warning meeting Feb 2008

by Berryman; and• Visit to Vietnam by Webb & Gledhill in late Nov 2008.


Summary• Objective 1

– Progress made according to expectations– Skill transfer for modelling hazard and loss consistent with

expectations– Probabilistic modelling to be addressed during current

training at GNS Science• Objective 2

– Overview guidance on VietNet provided (and ongoing)– Early warning system support provided

• Capacity Building concludes in April 2009• Memorandum of Understanding GNS Science/VAST in

place– Future collaboration anticipated– Future funding support needed

tsunami hazard and risk assessment and warning system for coastal areas of vietnam

Documents

technical review

continuitygns scienceobjective

continuitygns scienceroadmap

tsunami sources

tsunami early warning

capacity of scientists

subduction source mw

dr ken