training - tsunami hazard and vulnerability for decision makers planners and managers of coastal...

Content Index

Review Summary

Acronyms

Chapter 1: Origin and cause of Tsunami

1.0 Introduction 2

1.1 What is a Tsunami 2

1.2 Phenomenon of Tsunami 2

1.3 How Tsunamis are triggered 3

1.4 Factors for Determining the Magnitude of Tsunami 7

1.5 How does a Tsunami propagate? 9

1.6 Where Tsunami occurs 9

1.7 How behaves a Tsunami, when it approaches land? 12

1.8 What are the potential impacts of Tsunami? 13

Chapter 2: Tsunami threat in Bangladesh

2.0 Introduction 17

2.1 Bangladesh and Tsunami Hazards 17

2.2 Bangladesh and tsunami vulnerabilities 20

Chapter 3: Tsunami forecasting and Early Warning System

3.0 Introduction 23

3.1 What is the relation between Tsunami Forecasting and Early

Warning System?

23

3.2 Tsunami Forecasting and Early Warning Process 25

3.2.1 1st Component: Earth Data Observation 25

3.2.2 2nd

Component: Data and Information Collection 27

3.2.3 3rd

Component: Tsunami Detection 27

3.2.4 4th

Component: Tsunami Warning Decision Support 30

3.2.5 5th

Component: Warning and other products 30

3.2.6 6th

Component: Dissemination and notification 30

3.2.7 7th

Component: Community connections 32

3.3 Approach to carry out an Early Warning System? 32

3.4 The Four Elements of Effective Early Warning Systems 33

3.5 Preparedness steps for Tsunami forecasting and Early Warning

System

34

3.6 Bangladesh TF and EWS 35

Chapter 4: The Tsunami vulnerability on Production sector

4.0 Introduction 37

4.1 Fisheries Industries 37

4.1.1 Fish Farming 37

4.1.2 Productivity and Livelihood 39

4.1.3 Import and Export 40

4.1.4 Fish Species 41

4.1.5 Critical Fishery Infrastructure 41

4.2 Agriculture Sector 42

4.3 Industry 44

4.4 Tourism 46

Chapter 5: The Tsunami vulnerability on social sector

5.0 Introduction 52

5.1 Impact of Tsunami on Housing Sector 52

5.2 Health infrastructure 55

5.3 Education 58

5.4 Water Supply, Drainage and Sanitation 60

Chapter 6: The Tsunami vulnerability on Infrastructure sector

6.0 Introduction 64

6.1 Electricity Generation, Operation and Distribution and

Telecommunication

64

6.2 Transportation 66

6.3 Urban Development 68

6.4 Coastal Infrastructure including Ports and Jetties 69

6.5 Natural Infrastructure 71

6.6 Critical Emergency Response services 71

Chapter 7: Systematic Approach for Mainstreaming Disaster Risk Reduction in

Development Planning

7.0 Introduction 74

7.1 Approaches for Successful Mainstreaming 75

7.2 Tools for Mainstreaming DRR in Development 78

7.2.1 Collecting and Using Information on Natural Hazards 80

7.2.2 Poverty Reduction Strategy 80

7.2.3 Country Programming 81

7.2.4 Project Management Cycle 82

7.2.5 Logical and Results-Based Frameworks 83

7.2.6 Environmental Assessment 85

7.2.7 Economic Analysis 85

7.2.8 Vulnerability and Capacity Analysis (VCA) 85

7.2.9 Sustainable Livelihood Approaches 86

7.2.10 Social Impact Assessment 86

7.2.11 Construction Design, Building Standards and Site Selection 87

7.2.12 Evaluating Disaster Risk Reduction Initiatives 87

7.2.13 Budget Support 87

Chapter 8: Community Based Tsunami Preparedness Planning

8.0 Introduction 93

8.1 Family level Planning for TPP 93

8.2 Community based Tsunami Preparedness Planning (CBTPP) 94

8.3 Conclusion 103

Glossary Tsunami Terminology 104

List of Figures

Chapter 1: Origin and cause of Tsunami

1.1 Tsunami Waves Approaching Coastal Area 2

1.2 Worldwide tectonic plates and their interaction 4

1.3 The different fault-types 5

1.4 The tectonic plate motions 5

1.5 Step-by-step process for Tsunami to be generated by an earthquake 6

1.6 Location of Krakatau Volcano 7

1.7 The eruption of Krakatau in 1883 triggered a large Tsunami killing

over 36,000 people.

7

1.8 Matrix to evaluate the scale of risks linked to magnitude and distance

to epicenter

8

1.9 Distribution of Tsunami in the world 10

1.10 Correlation between Tsunami

Wave Speed and Water Depth

12

1.11 Indonesian Tsunami size scale. Take into consideration that Tsunami

can reach three times this height

12

1.12 Mechanism of Tsunami Formation 13

1.13 Tsunami hitting the coastal line of Penang

14

1.14

1.15 The Tsunami aftermath in Indonesia; important aspects:

amount of debris, structural destructions, stagnant waters

15

Chapter 2: Tsunami threat in Bangladesh

2.1 Bangladesh fault lines and historical magnitude recordings 18

2.2 Seismicity of Southern Asia 19

2.3 Seismic map of South Asia 20

2.4 Tsunami vulnerability map of Bangladesh 21

Chapter 3: Tsunami forecasting and Early Warning System

3.1 Tsunami Forecasting and Early Warning System 28

3.2 DART based Tsunami Monitoring System 29

Chapter 4: The Tsunami vulnerability on Production sector

4.1 Dead fish along Penang island Malaysia 38

4.2 Losses in income generating sectors

40

4.3 Boats damaged by Tsunami 2004 42

4.4 Damage to Tourism in Thailand during Tsunami 2004

47

Chapter 5: The Tsunami vulnerability on social sector

5.1 Damage to coastal housing during Tsunami 2004 53

5.2 Damage to Hospital during Tsunami 2004 55

5.3 Damage to water supply infrastructure during Tsunami 2004 61

Chapter 6: The Tsunami vulnerability on Infrastructure sector

6.1 Power and Telecommunication damage due to Tsunami 64

6.2 Impact of Tsunami on Coastal Road 67

6.3 Damage to Bridges causes by Tsunami waves 67

6.4 Impact of Tsunami Waves on Coastal Infrastructure 69

Chapter 7: Systematic Approach for Mainstreaming Disaster Risk Reduction in

Development Planning

7.1 Steps to Success Mainstreaming process 78

7.2 process of Mainstreaming DRR in Development 79

7.3 Integration of disaster risk concerns into a poverty reduction strategy 80

7.4 process of introducing DRR in poverty reduction strategy 81

7.5 Integration of disaster risk concerns into country programming 82

7.6 Project Cycle 83

7.7 Integration of disaster risk concerns into log frame analysis and

results-based management in hazard-prone countries

84

7.8 Integration of disaster risk reduction in environment assessment 88

7.9 Economic Analysis 89

7.10 Vulnerability and Capacity Assessment 90

7.11 Integration of DRR in Livelihood Approaches 90

7.12 Integration of Disaster Risk Concerns at Budgetary Support

List of Acronyms

ADPC Asian Disaster Preparedness Center

AIT Asian Institute of Technologies

AOR Area of Responsibility

BPR Bottom Pressure recorder

CCR Coastal Community Resilience

CTBTO Comprehensive Nuclear Test Ban treaty organization

DART Deep Ocean Assessment and Reporting of Tsunami

EWS Early Warning System

GCN Global Core Network

GLOSS Global Sea Level Observing System

GSN Global Seismic Network

GTS Global Telecommunications System

IOC Intergovernmental Oceanographic Commission

IRIS Incorporated Research Institutions for Seismology

LAN Local Area Network

NDMO National Disaster Management Office

NDWC National Disaster Warning Center

NEIC National Earthquake Information Center

NGO Nongovernmental organization

NMC National Meteorological Centers

NOAA National Oceanic and Administration

NTWC National Tsunami Warning Center

PDC Pacific Disaster Center

PSMSL Permanent Service for Mean Sea Level

RTH Regional Telecommunication Hubs

RTWP Regional Tsunami Watch Provider

UNESCO United Nations Educational, Scientific, and Cultural Organization

USGS U.S. Geological Survey

WAN Wide area network

WMO World Meteorological Organization

WTWP World Tsunami Warning Provider

Executive Summary

The unsustained rapid industrial development and urbanization in developing world is

adding vulnerability to the society. Recent frequent disasters have increased losses

many folds. The Tsunami 2004 affected larger part of South-South East Asia killing

more than 295,000 people from 11 countries. This event has given new dimension to

disasters which stretched across the contingent, leaving long term horrible impression

on our social system.

Respective governments have taken lead role along with United Nations and

international organisations to build the resilience in society to combat with such awful

situation. Bangladesh government has taken firm commitment to develop extensive

programme to understand earthquake and Tsunami hazards of whole country, seismic

microzontion of major urban area, contingency planning and development of early

warning system for various local hazards under Comprehensive Disaster Management

Program. This program is supported by European Union, United Nation Development

programme, Department of International Development and Government of

Bangladesh.

One of the components of this project is capacity building about Tsunami hazard and

vulnerability for decision makers/ planners and managers of coastal infrastructure The

capacity building activities will be organized in three different cities of the coastal

area (Barishal, Coxs Bazar and Khulna) to educate the vulnerability and nature of

warning of the Tsunami hazard to the decision makers/planners and mangers of the

coastal critical infrastructures. It will focus on the reduction of risks to the coastal

livelihoods posed by Tsunami events.

The course material has been developed to understand the mechanism of Tsunami

occurrence, Tsunami hazards in Bangladesh, Tsunami Forecasting and Early waning

system, impact of Tsunami on various coastal critical Infrastructures, approaches for

mainstreaming Tsunami disaster reduction in regular development and community

planning mechanism. The concept has been linked to past experience of Tsunami

2004 with context of Bangladesh.

The course material has been developed in view of requirements of senior level

officials associated with critical infrastructure in costal areas. The concept and

principles of Tsunami preparedness has been comprehensively related to Bangladesh

costal context. This will give better understanding for preparing the stakeholders for

Tsunami hazards.

The manual has been compartmented into eight chapters. The First Chapter discusses

mechanism of Tsunami, Linkage of earthquake with Tsunami, Propagation of waves,

probable spots for impacts etc. The second chapter describes status of Tsunami

forecasting system in Bangladesh. The chapter three deliberates on mechanism of

Tsunami forecasting and Early Warning System. Mechanism of Tsunami warning has

been discussed in line with concept of CONOPS. Chapter Four discusses Impact of

Tsunami on production infrastructure, including fisheries, agriculture, industry and

tourism in coastal areas. The fifth chapter discusses impact on social sectors like

education, health, water supply, sanitation and housing. Various aspects of damage

and losses in Bangladesh probable context has been discussed in the manual. Sixth

chapter discusses impact of Tsunami on critical infrastructure including transportation,

roads, bridges, coastal infrastructure like ports, jetties and harbours, emergency

service units etc. The seventh chapter discusses about approach and concept of

mainstreaming Tsunami disaster risk in sustained development. The chapter eight

discusses about community based planning for Tsunami risk reduction.

The reading material has been developed for capacity building of senior officials.

However, this material can be used for wide circulation among community,

government and nongovernment stakeholders.

*************************

1 Chapter Origin and Cause

of Tsunami Objective

The chapter aims at providing firm understanding about various terminologies used

in Tsunami risk management, occurrence phenomenon, wave propagation mechanism,

probable hazards associated with Tsunami risk.

Content Covers

What is Tsunami

Phenomenon of Tsunami occurrence

Triggering of Tsunami

Mode of wave propagation

Behaviour of Tsunami waves on coast

Potentials of Tsunami Waves

Origin and Cause of Tsunami

2


1.0 Introduction

Tsunamis are not new phenomenon; but the scope of the impacts they can generate is

getting more and more catastrophic as more and more human settlements are located

within hazard-prone areas. Preparedness and mitigation are thus necessary. To be

better prepared in front of Tsunami waves the origin and the causes of Tsunamis

should be well known.

1.1 What is a Tsunami?

Tsunami is a Japanese word, which means harbor wave 1 , named by Japanese

fishermen. In the deep ocean, they were not able to notice a Tsunami, thus it was only

when they were returning to their harbors that they were discovering the massive

destruction of their villages due to the path of a Tsunami.

1.2 Phenomenon of Tsunami

Tsunamis are a series of very large waves with

extremely long wavelength and long periods, generated

in a body of water by an impulsive disturbance that

displaces the water. Also known as seismic sea waves,

they represent a great threat as they attack coastlines resulting to damage property and

loss of life in the run-up zone.

In 80% of the cases2,

Tsunamis are

generated from

large, shallow

earthquakes with

the epicenter or

fault line located

near or on the ocean

floor. The waves

could travel away

Since 1850,

Tsunami across the

world has taken more

than 420000 lives.

Figure 1.1: Tsunami Waves Approaching Coastal Area

(Source: NOAA, US National Weather Service)


3

from the triggering source with speeds exceeding 800 km/h over very long distances.

From the area where the Tsunami originates, waves travel outward in all directions. In

the deep ocean,

Tsunami may reach only a few decimeters high above the water surface and the length

from crest to crest may be 100 km and more. This is why Tsunamis cannot be felt

aboard ships far from the seashore nor can be seen from the air in the open ocean.

Their speed diminishes as the waves enter shallower waters and jointly their height

increase. Tsunami waves look like a massive water wall and not as breaking waves

(Figure 1.1).

Since 1850 alone, Tsunamis have been responsible for the loss of over 420,000 lives3;

billions of dollars of damage to coastal structures and habitats; and widespread

colossal collateral damages. Predicting when and where the next Tsunami will strike

is currently impossible. Nevertheless, once the Tsunami is generated, forecasting

Tsunami arrival and impact is possible through modeling and measurement

technologies. That is why, preparedness on the what-to-do in case of such an

emergency, and fostering resilient communities and livelihoods, are prime

requirements.

1.3 How Tsunamis are triggered?

Four main causes can trigger Tsunamis which primarily include earthquake, volcanic

eruption, landslide activity and meteorites and

asteroids. Brief discussion is as below:

Earthquake spawns the most destructive and

common Tsunami, as it disturbs the ocean's

surface, causes abrupt displacement of the

seafloor, and vertically displaces the overlying

water. As a sudden tremor or movement of the earths crust, earthquake currently

generates most Tsunamis. Three main causes can explain earthquake occurrence.

Earthquake can be triggered by tectonic activity along the plate boundaries and

fault-lines, where geological plates collide.

Earthquake can be linked to an explosive volcanic eruption.

Tsunami can be

generated by earthquake,

volcanic eruption, massive

landslides, meteorites &

asteroids


4

Earthquake can be generated by man-made activities, like man-made

explosions, landslides, the filling of new reservoirs or the pumping of fluids

deep into the earth through wells.

The earth crust is composed of nine large and major tectonic plates that are constantly

in interaction. Constant and dynamic earth movements are at the source of

earthquakes, which then can lead to volcanic eruptions, landslides, soil liquefaction,

fire, floods and Tsunami. For more information on the different type of interactions

among the tectonic plates (Figure 1.2).

Figure 1.2: Worldwide tectonic plates and their interaction (Source: Source: US Geological Survey, The dynamic Earth, 1996.)

A Tsunami tremor occurs at a thrust fault: an oceanic plate dives under a continental

plate dragging it down until huge amount of energy is concentrated to snap the fault.

Different types of faults exist (Figure 1.3); either slip faults or strike slip faults can

trigger a Tsunami.

In a normal slip fault, the two involved blocks are pulling away from each

other, which lead to one of the fault blocks slipping upward and the other one


5

downward with respect to the fault line. The resulting scarp may reach 300

kilometers long and few to hundreds meters height.

In a dip slip fault the two blocks are pulling toward each other, causing an

overlaying of materials.

In a strike slip fault the blocks are moving horizontally. The material located

at the fault line is either torn apart or offset. mass of water. Tsunami scenario

is illustrated on Figure 1.5

Figure 1.3: The different fault-types (Source: www.geog.nau.edu)

Figure 1.4 below indicates zones of subduction. At this particular location, an earthquake may occur,

lifting the seafloor. Thus the water above the deformation zone is displaced from its equilibrium

position, resulting in waves and displacement of water causing Tsunami.

Figure 1.4: The tectonic plate motions (Source: U.S. Geological Survey (USGS) Map, This

dynamic planet)


6

. Volcanic Eruption: Much less frequently, Tsunamis can also be triggered by

volcanic activity, through an aboveground eruption or a submarine event-eruption,

cascades of ash or the collapse of volcanic flank. An impressive Tsunami was

triggered by volcanic activity in Krakatau, Indonesia in 1883. See below (Figures

1.6 and 1.7) the location of Krakatau volcano and the illustration of the scope of

its impressive eruption in 1883. This volcano is still currently active.

Figure 1.5: Step-by-step process for Tsunami to

be generated by an earthquake. (Source Roach 20)

Landslides moving into oceans, bays or lakes often occur during a large

earthquake or volcanic eruption. These landslides displace the water from its

equilibrium position and therefore generate a Tsunami. The largest Tsunami wave

ever observed was triggered by a rock fall in Alaska on July 9, 1958. A huge

block (40 million cubic meter) fall into the sea generating a huge wave.


7

Figure 1.6: Location of Krakatau Volcano

Figure 1.7: The eruption of Krakatau in 1883 triggered a large Tsunami killing over 36,000

people. (Source: www.gfd-dennou.org)

Meteorites / Asteroids: Falling of three-to-four-miles-diameter meteorites or asteroids

can also trigger Tsunamis, however it is very rare.

1.4 Factors for Determining the Magnitude of Tsunami

The main factor determining the initial size of a Tsunami is the amount of vertical sea

floor deformation. The parameters that condition the deformation are:

Earthquake's magnitude,


8

Earthquakes depth,

Fault characteristics

Topography of the coastline and of the ocean floor.

Usually, an earthquake that deform the sea bottom

and displace enough water to propel destructive wave

pulses for a thousand miles has to be colossal, at least

a magnitude of 7.5 on the Richter scale. Please refer

to the Figure 1.8 matrix to evaluate the scale of

coastal risks linked to magnitude and distance from

epicenter.

Figure 1.8: Matrix to evaluate the scale of risks linked to magnitude and distance

to epicenter (Source- Chapter 6: Tsunami Warning Decision Support, Tsunami Warning Center Reference Guide, USAIDS-NOAA-IOTWS, 2007, p.6-6)

After an earthquake has triggered a Tsunami, different parameters influence the size

of a Tsunami along the coast, as the waves enter shallow water. Few of the factors are

mentioned below:

The shoreline and bathymetric configuration,

The velocity of the sea floor deformation,

The water depth near the earthquake source,

Earthquake

magnitude, depth, fault

characteristics & topology

of coastlines influences the

magnitude of Tsunami


9

The efficiency of energy transferred from the earth's crust to the water column.

1.5 How does a Tsunami propagate?

Several parameters influence the wave propagation of a Tsunami. First of all, the

speed of the Tsunami wave depends essentially to the depth the earthquake in the

ocean floor occurs: in fact, the deeper the water, the faster the Tsunami wave will

travel. Tsunamis total energy4 is spread over a larger and larger circumference as the

waves travel and lose very small original energy during propagation process. Thus

they can propagate very far (several thousands kilometers from the epicenter), in all

directions. The earth movements associated with large earthquakes are thousand of

square kilometers in area. Therefore, any vertical movement of the seafloor

immediately changes the sea-surface. The energy of the set of waves produced is

concentrated at the wavelengths. This ultimate depends on the earth movement. The

height of the waves is determined by vertical displacement and wave directions rely

on the adjacent coastline geometry.

The main difference between wind-generated waves and Tsunami waves relies on

wavelengths. Tsunami waves are characterized by shallow-water waves with long

period and wavelengths. A wave becomes a shallow-water one when the ratio

between the water depth and its wavelength gets very small.

Tsunamis are phenomena, which move the entire depth of the ocean often several

kilometers deep, rather than just the surface, so they contain immense energy,

propagate at high speeds and can travel great trans-oceanic distances with little overall

energy loss.

Each earthquake is unique, thus every Tsunami has unique wavelengths, wave heights

and wave directionality. From a Tsunami warning perspective, it seems daunting to

forecast the characteristics of a Tsunami in real time.

1.6 Where Tsunami occurs

Tsunamis can be generated in all parts of the worlds oceans and inland seas. Each

region of the world appears to have its own cycle of frequency and pattern in

generating Tsunamis that range in size from small to the large and highly destructive

events. As submarine earthquakes5 trigger most of the Tsunamis, the Pacific region is

highly concerned (figure 1.2), because the Pacific covers more than one-third of the


10

earth's surface and is surrounded by a series of mountain chains, deep-ocean trenches

and island arcs called the "ring of fire" -where due to subducting geological plates,

dense oceanic plates sliding under the lighter continental plates- most earthquakes

occur in this area. The concentration of the dots draw the different fault lines, the

contact zone between tectonic plates. In South-east Asia, the confrontation between

the Indo-Australian plate and the Eurasian one triggers a lot of earthquakes. Figure 1.9

shows world tectonic maps.

Figure 1.9 : Distribution of Tsunami in the world (Source: www.Tsunami-alarm-system.com)

Tsunamis can also occur in the Atlantic Ocean, in the Indian Ocean and the

Mediterranean Sea and even within smaller bodies of water, like the Sea of Marmara,

in Turkey.

A Tsunami can propagate in all directions and very

far from the epicenter, thus all coastal areas in the

world, especially in the Pacific are potentially

exposed to seismic sea waves and its destructive

impacts; according to the Pacific Disaster

Management Information Network, the December 26, 2004, Tsunami killed about

295,0006 people along the coast areas of 11 countries. In fact, distant shores of

countries located very far away from the epicenter have also been hardly affected by

Tsunami 2004, 26

December, killed more than

2,95,000 peoples affecting

11 counties.


11

Tsunami waves impacts. In Sri Lanka, 30,000 people died due to Tsunami; 8,000 in

India; 90 in Myanmar; 75 in the Maldives and 2 in Bangladesh. Even now, the exact

number of fatalities is still unknown in major area.

Aug. 27, 1883- Java and Sumatra islands: Eruptions from the Krakatoa

volcano fueled a 30-meter Tsunami that drowned 36,000 people

in the Indonesian Islands of western Java and southern Sumatra.

Krakatoa Island is situated just above the subduction zone of

the Eurasian plate and the Indo-Australian plate. The strength

of the waves pushed coral blocks as large as 600 tons onto the

shore.

June 15, 1896- East coast of Japan: Waves as high as 30 meters, spawned by

an earthquake, swept the east coast of Japan. Some 27,000

people died

July 9, 1958- Lituya Bay, Alaska: Considered as the largest recorded in

modern times, the Tsunami was caused by a landslide triggered

by an 8.3 magnitude earthquake. Waves reached a height of

576 meters in the bay, but because of the non-presence of

vulnerable elements -the area is relatively isolated and in a

unique geologic setting- the Tsunami did not cause much

damage. It sank a single boat, killing two fishermen.

May 22, 1960- Chile: The largest recorded earthquake, magnitude 8.6, created

a Tsunami that hit the Chilean coast within 15 minutes. The

surge, up to 25 meters high, killed an estimated 1,500 people in

Chile and Hawaii.

Aug. 23, 1976 Philippines: A Tsunami in the southwest killed 8,000 on the

heels of an earthquake.

July 17, 1998 Papua New Guinea: A magnitude 7.1 earthquake generated a

Tsunami: three waves measuring more than 7 meter high struck

a 10-kilometer stretch of coastline within ten minutes of the

earthquake/slump. Three coastal villages were swept

completely and 2,200 people dead.

December Indian Ocean: The deadliest natural disaster, magnitude of 9.0

to 9.3, generated a series of lethal Tsunamis that killed

approximately 300,000 people. The scope of the Tsunami was

colossal, from the immediate vicinity to the quake coastal areas

(Indonesia, Thailand, Malaysia) to very distant areas (The

Maldives, India, Sri Lanka, Somalia, Tanzania, Kenya

Bangladesh): this type of widespread Tsunami is called

teleTsunami or intercontinental Tsunami.

26, 2004-

T

I

M

E


12

1.7 How behaves a Tsunami, when it approaches land?

As the waves enter shallower waters of the coastal areas, the velocity of the waves

decreases to about 50-60 km/h, combined with the concentration of energy inside a

smaller water volume: their heights increase drastically. Figure 1.10 demonstrates the

link between decreasing Tsunami wave speed and decreasing water depth.

Figure 1.10- Correlation between Tsunami

Wave Speed and Water Depth

(Source: NOAA) Figure 1.11: Indonesian Tsunami size

scale. Take into consideration that

Tsunami can reach three times this

height. (Source: Wikimedia)

In fact, as the Tsunami waves become compressed near the coast, the wavelength is

shortened whereas the amount of energy stay equal; thus the wave energy is directed

upward, that is why their heights considerably increase. When the waves become

closer to the coastal areas, a large Tsunami can crest

to heights exceeding 30 m or the water level could

rise in a very short time for several tens of meters.

Areas are at greater risk if they are less than 25 feet

above sea level and within a mile of the shoreline.

The first wave of the series may not be the largest. For comprehensive understanding

of Tsunami wave behavior, see illustration on Figure 1.12.

Tsunami waves can

raise up to the height of 30

meters


13

1.8 What are the potential impacts of Tsunami?

As Tsunamis arrived on the coastal areas, they are carrier of three factors of

destruction:

Inundation (Scope of inundation may be referred to figures 1.13 and 1.14)

Wave impact on structures (refer to Figure 1.13)

Erosion (refer to figures 1.14 and 1.15)

Figure 1.12 Mechanism of Tsunami Formation( Source : Reuters)

In fact, Tsunamis present the capacity of inundating hundreds of meters inland. They

have great erosion potential and can strip beaches of sand and undermine trees and

other coastal vegetation.

Figure 1.13: Tsunami hitting

the coastal line of Penang (Source: Sydney Morning Herald,

December 2007)

Figure 1.14


14

Structural infrastructures like bridges; seawalls; roads and coastal buildings are also

exposed to Tsunamis forces and can be totally demolished by the strong currents

induced by them. Flotation and drag forces move houses, cars and boats.

Figure 1.15: The Tsunami aftermath in Indonesia; important aspects:

amount of debris, structural destructions, stagnant waters.

Source: www.scienceray.com

Apart from Tsunami waves, the coastal area will be

affected by earthquake ground shaking, liquefaction,

subduction, fire, etc. Tsunamis induce many

collateral risks, as water entails a high and long-term

destructive potential. Usually greater risks appear

when the waves are withdrawing. Floating debris are

actually the most damaging component as they may

crash into buildings, break power lines and may start fire. Fire from damaged ships in

ports, rupture of oil storage tanks and refinery facilities can in fact cause more

damages than the Tsunami itself.

Stagnant water after the Tsunami stroke in the different preexisting or newly formed

geological troughs implies high risk of water-borne diseases that severely affect the

survivors. Impacts of Tsunami on various critical infrastructures have been discussed

in chapter 4, 5, 6.

Tsunami can impact

due to inundation, wave

impacts, massive erosion,

grounds shaking and other

collateral hazards

associated with earthquake

energy release.


15

1 What is a Tsunami?, UN/ISDR International Strategy for Disaster Reduction, http://www.unisdr.org/ppew/Tsunami/what-is-Tsunami/backinfor-brief.htm 2 Tsunami Glossary, International Tsunami Information Centre,

http://ioc3.unesco.org/itic/files.php?action=dlfile&fid=785&PHPSESSID=fe3dd111fdf639e407909fa2f75148aa

3 The Tsunami story, NOAA, http://www.Tsunami.noaa.gov/Tsunami_story.html.

4 How does Tsunami energy travel across the ocean and how far can Tsunamis waves reach?, Tammy Kaitoku, ITIC/UNESCO,

http://ioc3.unesco.org/itic/contents.php?id=164

5 Tsunami Glossary, International Tsunami Information Centre,

http://ioc3.unesco.org/itic/files.php?action=dlfile&fid=785&PHPSESSID=fe3dd111fdf639e407909fa2f75148aa

6 Malaysia Plans To Dedicate Separate Cell Phone Frequency To Warn Of Tsunami FEMA, 2008,

http://www.fema.gov/emergency/reports/2006/nat042806.shtm,

2 Chapter Tsunami Threat in

Bangladesh Objective

The chapter aims at providing status of Tsunami in Bangladesh and current initiatives

Content Coverage

Status of Tsunami in Bangladesh

Current initiatives for Tsunami Forecasting and Early Warning System

Tsunami Threat in Bangladesh

17


2.0 Introduction

Bangladesh has not been hit by large tsunamis. Nevertheless the December 26, 2004

tsunami in the Indian Ocean highlighted the threat the whole region is submitted and

the disastrous impacts it can generate. Located in a high seismic zone Bangladesh is

considered as a hazard-prone zone. This is why preparedness planning towards

tsunami needs to be considered and implemented in the country.

2.1 Bangladesh and Tsunami Hazards

Due to its geographical situation in a highly active seismic zone, as the Figure 16

demonstrates, Bangladesh is surrounded at its eastern side by several fault lines that

have proved over history their capacity to generate earthquakes.

Coastal areas

like Coxs Bazar, Silhet, Barisal, can be

affected by tsunami

waves

In Figure 2.1 circle indicates the magnitude of the earthquake; It

can be assumed that the country is exposed to high risks given

the rapid urbanization process at stake, especially in Dacca,

Chittagong. Silhet, Barisal. These cities are playing a colossal

economic role in the national economy of Bangladesh. Especially

coastal cities highly participate to Gross National Product and

contribute through their harbors to Bangladesh regional

influence. These coastal cities are going to be the first one hit by

Tsunami waves thus leading to the breakdown of economic

poles. The expected and long-term damages on life, livelihood,

ecosystems, infrastructures and facilities will impede Bangladesh

to pursue its development path.


18

Figure 2.1: Bangladesh fault lines and historical magnitude recordings (Source: http://banglapedia.net/Maps/ME_0002.GIF )

Furthermore, it is stated that Tsunami can spread in all directions and Bangladesh

is located in a very highly seismic dynamic zone, the scope of seismicity might be

referred at Figure 2.2; the country is thus currently exposed to multi-source

hazards, and particularly Tsunami occurrence. Over the past 250 years at the most

six Tsunamis were reported affecting the coast of Bangladesh1.


19

Figure 2.2: Seismicity of Southern Asia

(Source: British Geological Survey, www.gsrg.nmh.ac.uk)

Moreover, the slope of Bangladesh in coastal areas is low; therefore the waves can

move further inland. Several hundreds meters from the shore can be then

devastated in case of a Tsunami disaster, which is more than the mean inundation

distance. Bangladesh is facing increasing risks, risk assessment mapping may be

consulted on Figure 2.3.

Natural disaster is the threat number one on food and livelihood security in

Bangladesh. Currently, along the 700 kilometers long coastal front, 28% of the

total coastal population might be the worst affected if a Tsunami hits the country.

Moreover, the constant increase of coastal population, that will reach 43.9 million

by the year 2015 and 60.8 by 2050 according to UNDP2, leads the country to be

even more vulnerable to disasters.


20

Figure 2.3: Seismic map of South Asia (Source: : Geology, Seismic Hazard map, South Asia)

Bangladesh is prone to annual flood, cyclone, tidal bore and coastal surges. All

these hazards have similar impacts as Tsunami. Further steps have been taken to

prevent cyclone and flood impacts within the country; similar involvement

concerning Tsunami preparedness and mitigation risk should be undertaken.

It is assumed that there is an urgent need to curb vulnerability and prepare the

country to natural hazards occurrence. Early warning system to prevent risks;

preparedness among the populations and improvement of city planning and land

settlement should be considered and developed in Bangladesh so as to build

resilient communities in face of natural hazards.

2.2 Bangladesh and tsunami vulnerabilities

The vulnerability of Bangladesh concerning Tsunami hazard may be referred on

Figure 2.4. Vulnerable coastal zoning in Bangladesh is divided in three areas, each

one characterized by a specific level of risk.

- The first zone, including all coastal lines of Chittagong district comprising

Coxs Bazar, is mostly prone to disasters as it is very close to the tectonic

interface between Indian and Burmese plates.


21

- The second zone, which embraces half of Khulna district is moderately

vulnerable.

- The third one, comprising the Barisal district, is considered as less vulnerable

due to presence of numerous islets and shoals in the upper regime of the

continental shelf.

Figure 2.4: Tsunami vulnerability map of Bangladesh (Source FAO)

Bangladesh is prone to erosion, which leads to massive people displacement. The

annual erosion rate in the Meghna estuary during 1973-2000 is 3,199 ha per year3.

Hundred of thousands people have then no choice than to move; it is current in

Bangladesh that people are displaced 10 to 14

times4

. Tsunami hazard will drastically

accelerate erosion process, leading to coastal

structural destruction and more people displaced.

Bangladesh is in

process of developing state

of art end to end Tsunami

early warning system and

forecasting system


22

The few impacts in Bangladesh of the December 26, 2004 massive

Indian Ocean Tsunami

The 26 December 2004 Tsunami has devastated many countries in the Indian Ocean, but

Bangladesh hasnt been hardly hit compared to its neighboring countries. Three hours after Tsunami hit coastal front of Bangladesh with only 25 to 30

centimeters high waves.

How can we explain Bangladesh has been saved from Tsunami devastation?

Different factors explain this phenomenon:

- Long distance to epicenter

- 200 kilometers of continental shelf

- Thick sedimentation in Bengal fan

- High density of sea water in Bay of Bengal around and along the coast

- Anti clockwise oceanic current at the Bay of Bengal during wintertime

Concluding Remarks

Macro analysis of the region reflects risk of Tsunami in Bangladesh coast hitting Cox

bazaar, Khulna area. However, there is need for developing detailed Tsunami hazard

mapping of coastal Bangladesh. In this regard, the progress has been made. Several

noted and leading national and international technical experts and research

organizations are involved in developing Tsunami hazard maps for Bangladesh.

1 REPORT, June 2005, Ministry of Food and Disaster Mitigation of the Government of the Peoples Republic of Bangladesh.

2 Coastal population in Bangladesh to bear brunt if Tsunami strikes, UNDP, January 2009,

http://www.undp.org.bd/info/events.php?newsid=387&t=In%20News 3 Rafiqul Islam, Coastal Planning and land use Policies and issues in Bangladesh, FAO Regional Workshop, September 2006,

Bangkok, Thailand,.

4 Idem

22

3Chapter Tsunami Forecasting

and Early Warning

System

Objective

to understand the concept of disaster warning and early warning system

Content Coverage

Relationship between Tsunami forecasting and early warning system

Process of Forecasting and Early warning system using CONOPS

Approach to carry effective Early warning to community

Preparedness step for Tsunami forecasting and early warning system

The status of early warning system in Bangladesh

Tsunami Forecasting and Early Warning System

23


3.0 Introduction

Natural hazards become disasters only if the

population, the communities are not prepared and

cant cope with the effects of a natural hazard. For

instance, torrential rain in the middle of the ocean

would not cause any disaster, but the same

amount of water falling on top of a vulnerable population for example, a

shantytown on a cleared hillside or near riverbank- would trigger landslides,

floods and a huge loss of life. Vulnerability represents the potential consequences

on human beings and its infrastructures knowing its exposure on natural hazard.

Vulnerability coupled to natural hazard are the two components that provoke

disaster.

The major aspects of vulnerability are the following:

- Growing poverty,

- Environmental degradation,

- Populations crowded in risky locations,

- Civil strife,

- Lack of knowledge and preparedness

Concerning Tsunami hazard, vulnerability should be reduced through Tsunami

forecasting and Early Warning System. This chapter aims at giving specific and

concrete indications to mitigate Tsunami risks.

3.1 What is the relation between Tsunami Forecasting and Early Warning

System?

Decision makers must be aware when an underwater quake occurs; thus the

consequential potential Tsunami waves that might arrive can be forecasted.

Forecasting is only useful if coastal populations are informed of the risks and take

appropriate measures to prevent losses of life and properties. The information

relays through Early Warning Center to disseminate warning messages within the

exposed populations.

Tsunami Forecasting

and early warning system is

essential part of Tsunami

preparedness and

management.


24

Considering the risks the whole region is exposed to, Tsunami warning system

has provided warnings of potential Tsunami danger in the Pacific basin since 1946.

It aims at monitoring earthquake activity and the passage of Tsunami waves at tide

gauges.

Nevertheless, earthquake data is not sufficient to predict the physical

characteristics and impacts of the forthcoming Tsunami. Moreover, tide gauges

placed in harbors provide direct measurements of the Tsunami, but the Tsunami is

significantly altered by local bathymetry and harbor shapes. 15 of 20 Tsunami

warnings issued since 1946 were considered false alarms because the Tsunami

that arrived was too weak to cause damage. Since then, improvements have been

done.

Currently, deep ocean Tsunami detectors, called tsunameters, have been

developed and can now provide the data necessary to make Tsunami forecasts in

real time.

The Pacific Tsunami Warning Center operated by the US NOAA based in Hawaii

issues most Tsunami warnings in the Pacific Area. Although, more and more

regional warning system have been implemented, using the traditional knowledge

of the communities and increasing the rapidness of the prediction. To relay the

Tsunami forecast implementing early warning system is crucial so as to spread the

information and disseminate warnings on the coastlines.

Raising awareness and training among the coastal population are necessary for

them to understand the risks they are living with and to know what to do in case of

an emergency. To this extent, disastrous losses of life can be prevented.

Tsunami Forecasting and early warning system ate two faces of the same

coin but there is a basic difference.

Forecasting is defined as Statement or statistical estimate of the occurrence of a

future unknown event. (Australian Emergency Management Glossary, 1998)

Early Warning System is the provision of timely and effective information,

through identifying institutions, that allow individuals exposed to a hazard to

take action to avoid or reduce their risk and prepare for effective response (ISDR, 2003)


25

3.2 Tsunami Forecasting and Early Warning Process

Tsunami Warning Center Reference Guide 1

provides extensive information about the

approach and process of Tsunami forecasting

and early warning system. The suggested

model has 7 (Figure 3.1) components

including Earth Data Observation, Data

Information Collection, Tsunami Detection,

Tsunami Decision Support, Warning and

Other Products, Dissemination and

Notification, and Community connection. This

model has been accepted widely by Tsunami prone countries and is in the process

of implementation.

The purpose of this operational chain is to provide real-time monitoring, alert of

seismic and Tsunami activities, timely decision making and dissemination of

information to prevent disastrous impact. Each step is crucial to the overall

strength and functionality of the chain.

3.2.1 1st Component: Earth Data Observation

Earth data observation relies basically on two variables: Seismic data and sea level

data. Relevant and efficient observation relies on network involvements, the required

are mentioned below:

Seismic data

GSN/CTBTO Seismic Networks

This network provides data for earthquakes occurring more than 1,000 kilometers

from the measurement site. Nonetheless, precise and rapid data on local Tsunami

event may be not efficiently provided.

Local Seismic Networks

This network aims at reducing the approximate assessments made by the international

network by the installation of local measurement system at the NTWC or at the

NTWP level. This implies seismometer installation, maintenance program and

End to End early

warning system is composed

of seven components

including Earth Data

Observation, Data

Information Collection,

Tsunami Detection, Tsunami

Decision Support, Warning

and Other Products,

Dissemination and

Notification, and Community

connection


26

communication program. It is assumed that there is a need to rely on various seismic

networks in any critical areas.

Sea-level Data

GLOSS Tide Gage Networks

GLOSS is an international program conducted under the auspices of the Joint

Technical Commission for Oceanography and Marine Meteorology of the World

Meteorological Organization (WMO) and the Intergovernmental Oceanographic

Commission (IOC). Through its 290 sea level stations and its Permanent Service for

Mean Sea Level (PSMSL), GLOSS is a predominant provider for data and

information.

Local Tide Gage Networks

The same as for seismic data collection, international centers may not be able to

provide relevant data on local Tsunami events; therefore installation of regional level

tide gages network is required. Two types of gages exist: Coastal tide gages at the

land-sea interface that can only provide immediate warnings; and open ocean buoys at

distant locations that can provide advance warning. DART (Deep Ocean Assessment

and Reporting of Tsunami) buoys are widely used for (Figure 3.2) assessment and

monitoring of Tsunami Waves. This acts as a relay of information between

Tsunameter and satellite network.

3.2.2 2nd

Component: Data and Information Collection

This second component relies on several parameters as described below. Highly

developed communication is required to reduce delay of information transmission.

National Earthquake Information Center (NEIC) receives event impacts report

from national, state and local agencies and the public is necessary to foster a

comprehensive communication system. Tight relations and sharing data should be

instituted between National Tsunami Warning Centers (NTWCs) and Regional

Tsunami Watch Provider (RTWPs).

Satellite communication

Data sharing on hydrological, meteorological, alerts and warnings among Global

Telecommunications System (GTS), NTWC and RTWP should be rapid and

systematic. IRIS GSN (Global Seismic Network) encompasses 130 stations and has


27

great capacities to provide Tsunami warnings, emergency response and monitoring

underground explosions. Another important actor in data and information collection is

the Intergovernmental Oceanic Commission (IOC) of the WMO.

Broadband and Telephone

The broadband and telephone are common and widely used tools for data and

information collection

National Tsunami Warning Centers

It should have different types of communication relays, like land lines, wireless

telephone, radio, internet, etc. it is advised to have backup communication

alternative communication paths within the center- and backup networks

communication provided by another partner center, like RTWP.

Regional Tsunami Watch Provider Bulletins

Threshold criteria to be stressed in the initial bulletin: Location of the earthquake;

Depth of the earthquake from the earths surface; Magnitude of the earthquake.

Tsunami Warning Center must monitor recorded Tsunami effects through tide gages

and Tsunameters to confirm the existence or the nonexistence of a Tsunami and its

degree of severity.

3.2.3 3rd

Component: Tsunami Detection

The first step is to detect the occurrence of Tsunami through the localization and

the magnitude of the earthquake; then the impacts on the Area of Responsibility of

the NTWC or RTWP should be forecasted. There are two types of information

technology networks: Wide Area Network (WAN), like Internet and Local Area

Network (LAN), like internal network in an office.

Tsunami detection relies on computer programs and technologies, which includes

hardware, operating systems, DATA analysis software and DATA Integration

software. Computing mainly require technical installation, maintenance and

backup system. Data processing needs to be rapid, efficient and reliable; this is

why communication lines as a preliminary component have to be well established.

28

Figure 3.1: Tsunami Forecasting and Early Warning System (Source: Tsunami Warning Center Reference Guide, 2008)

29

Figure 3.2(a, b): DART based Tsunami Monitoring System (Source: CONOPS)

3.2.4 4th

Component: Tsunami Warning Decision Support

After the data has been processed by a Tsunami Warning Center, decision in a very

short time (20 minutes) has to be made whether a warning has to be issued.

Following the initial bulletin, NTWC is in charge of issuing a cancellation,

extension or final bulletin as appropriate.

Credibility may be entailed if false alert are given. It is also required that the

forecast is refined beyond the initial warning.

Three aspects enable decision-making mainly based upon science and historical

events:

Wave models

Criteria

Inundation Impacts

3.2.5 5th

Component: Warning and other products

Warning bulletins should be given by NTWCs and RTWPs. Evacuation plan must be

used for an earthquake with a magnitude equal or superior to 6.5 on the Richter scale.

This component encompasses four steps, as prcised below:

Warnings: the possible damages are communicated and evacuation is required

if necessary.


30

Watches: Tsunami may have long time travel, thus be aware of updated

warnings.

Advisories: Announce hourly bulletins and update the situation when

earthquake in AOR has occurred and might trigger a Tsunami.

Statements: One bulletin should be delivered if an earthquake has occurred in

AOR even if its magnitude doesnt presage a Tsunami.

3.3.6 6th

Component: Dissemination and notification

Dissemination is the process of physically getting the message within an AOR

center.

Notification concerns the understanding of the received message, through

outreach and education.

Dissemination and notification can be realized through partnerships, which

include the following:

First of all, between TWC and the international community to access global seismic and sea level networks;

Between TWC and all relevant actors within AOR, like national and local groups, and individuals.

The different agencies that require timely receipt of Tsunami bulletin message have to be listed, they are considered as customers, like

general public, NGO, government agencies.

Partners are other governmental or nongovernmental groups with role in the end-to-end Tsunami Warning system chain.

An effective information system would be ensured when responsibilities and

tasks are clearly distributed and transparency among actors is ensured.

Local government is responsible to foster warning system and to give

appropriate incentives to establish and further develop warning process warn,

prepare, respond and recover-. At national level government is leading

extensive research and development programs, and intelligence network

development on warning issues.

Trainings on dissemination have to be undertaken.

Private sector should have a significant role to play. The media industry for

instance can highly disseminate information related to Tsunami.


31

Civil society should also take part in dissemination and particularly in

notification. The society should able to develop mechanisms to disseminate

warnings to all the potentially affected people, through education and trust

building. The society can also help to formulate concise warning messages

everybody can understand, using familiar format.

The government has also a role to play as to ensure the legitimacy of the

warning. Administration should be highly involved in the process of

preparedness and resilience building. Formal planning and proactive

administration may follow the below steps:

Validate hazard/risk assessment

Approve warning point procedures

Approve Tsunami hazard zone map with evacuation routes

Learn procedures for canceling an evacuation for less-than-destructive

Tsunamis

Know how to report storm and Tsunami damage to the local NWS

office in near real-time

Approve storm spotter roster

Validate guidelines and procedures for activation of sirens, cable TV

override

Organize or supervise annual exercises, like evacuation drills and real-

time mock exercises

Several measures to facilitate the access of warning messages should

be put in place, like for instance a toll free number to get alert

messages.

Tsunami Warning Centers are responsible to organize public events, media

workshops, public school programs on Tsunami safety and preparedness so as

to build resilient communities in their AOR. They should also designate a

public affairs officer to coordinate media response. They should also

disseminate public safety during Tsunami emergencies and push for

community preplanning.


32

Public education should establish Tsunami evacuation routes and secure areas

and also Tsunami shelter outside hazard zone. They should install route signs.

They should provide written Tsunami information, including hazard zone

maps, evacuation routes, and basic Tsunami information.

3.3.7 7th

Component: Community connections

The purpose of this component is to reach as many people at risk as possible.

Take into consideration that potential audiences with specific vulnerabilities

might include elderly, children, local businesses, visitors, non native speakers ,

residents etc., Community partnerships are of great use to implement warning

system outreach.

Partnerships with the media should be ensured for better effectiveness of

warning and communication.

3.3 Approach to carry out an Early Warning System?

Forecasting a Tsunami can reduce the destructive impacts on communities

provided that an Early Warning System is put in place. Through the Early

warning system the populations living in the most vulnerable areas receive

warnings before the Tsunami hits the coastlines and structural emergency

planning is ready to take charge of the displaced people.

Information on the approaching Tsunami must be relayed among the

population of the coastal areas through public address systems and/or sirens in

less than 15 minutes. Tsunami warning systems feature multiple lines of

communications, such as radio, television, visual signals, sirens. The type of

alert should be adapted to the cultural context.

Educational programs on Tsunami mechanisms, the meaning of the alerts and

the what-to-do in case of a Tsunami should be given at the community level to

Case studies on the EWS efficiency In Japan, the population is educated about Tsunamis, evacuation plans has been

developed, and warning can be issued as a Tsunami approaches. Thus, the number

of casualties has clearly diminished: 15% of the population at risk died during

Aonae Tsunami in 1993. Without preparedness nor education, the impacts are far

more dramatic as it is stressed by the Warapa Tsunami in Papua New Guinea,

when 40% of the population at risk died in 1998 as no warning system existed and

no evacuation plan was available.


33

reduce vulnerability and thus the scope of the disaster.

To build an Early Warning System, it is crucial to consider the four following

elements as linked together. A failure in one element can lead to the failure of

the whole system. Therefore, it is very important for each team to meet others

for insuring that everybody knows and understands what the others are doing

and planning.

3.4 The Four Elements of Effective Early Warning Systems2

ISDR has suggested four elements of effective early warning system, which is

comprised of four components including risk knowledge, monitoring and warning

service, dissemination and communication and response capacity.

I- The Risk knowledge first step aims at

constructing risk scenarios, through the

gathering of precise data on natural

hazards and the vulnerability that prevails

in the zone where the assessment is being

conduct.

II- During the development of hazard

monitoring and early warning services, data and analysis of past events should

be incorporated so as to improve the early warning system itself.

III- Development and publishing of manuals mainly constitute the communication

and dissemination phase.

IV- After the processes of risk assessment, of early warning system

implementation, and safety education/dissemination program, Necessary tools

are disposed to prevent risks. Nevertheless, it is crucial to practice and test

operational procedures such as evacuations. Through mock exercises, drills,

safety plan can be completed and updated.

For effective early

warning system, four essential

components are risk

knowledge, Monitoring and

warning system,

dissemination and

communication and response

capability.


34

3.5 Preparedness steps for Tsunami forecasting and Early Warning System

Installation of detection systems through seismic stations, sea level gauges,

Tsunami detection buoys; develop technical knowledge, gain expertise on the

different tools (to predict Tsunami and to disseminate timely warnings);

generate hazard map

Advocate at national/regional level Disaster Risk Reduction policies

Reinforce coordination among actors

Training and raising awareness process inside the vulnerable zones; establish

evacuation mapping, shelters; foster resilient coastal communities

Upgrade data according to the local changes

Support and Enhance local/regional implemented warning system:

communities themselves involved in the data generation will be better

prepared to respond.

The process of Tsunami communication may be referred at Figure 3.1.

3.6 Bangladesh TF and EWS

The frequency of cyclone for instance has given the sufficient inputs to foster

a preparedness approach against cyclone surge. People are conscious of the

Risk knowledge

Systematically

collect data and

undertake risk

assessments

Are the hazards and

the vulnerabilities

well known? What

are the patterns and

trends in these

factors? Are risk

maps and data

widely available?

Monitoring and

warning service Develop hazard

monitoring and early

warning services

Are the right

parameters being

monitored? Is there a

sound scientific basis

for making forecasts?

Can accurate and

timely warnings be

generated?

Dissemination

and

communication Communicate risk

information and

early warnings

Do warnings reach

all of those at risk?

Are the risks and the

warnings

understood? Is the

warning information

clear and useable?

Response

capability Build national and

community response

capabilities

Are response plans

up to date and

tested? Are local

capacities and

knowledge made

use of? Are people

prepared and ready

to react to

warnings?

I II III IV


35

risks and know what to do in case of an alert. Cyclone shelters have been

installed in secure areas, outside cyclone vulnerability zone.

Nonetheless the country has not got a monitoring, measuring, early warning

system in place for Tsunami even if the risk is particularly high and the

vulnerability of population increasing.

The Ministry of Food and Disaster Management of the Government of the

Peoples Republic of Bangladesh has decided to tackle this gap and has

formulated in June 2005 several measures to implement a Tsunami Early

Warning System.

1 Tsunami Warning Center Reference Guide, US. Indian Ocean Tsunami Warning System Programme,

October 2007, Bangkok

2 Basics of Early Warning, UN/ISDR, http://www.unisdr.org/ppew/whats-ew/basics-ew.htm

4 Chapter Tsunami

Vulnerability on

Production Sector

Objective

To understand the Tsunami Vulnerability on Production Sector

Content Coverage

Identification of production sector in coastal areas

Various elements of production impacted by Tsunami

Experience of Production sector impact during Tsunami 2004

Tsunami Vulnerability on Production Sector

37


4.0 Introduction

Production sector plays major role in countrys

development as it provides opportunity to citizens

for livelihood, business and development. Impact

of Tsunami has been broadly discussed for four

sectors namely fishing, agriculture, industry and

tourism. The probable impacts on these sectors

are discussed in detail in following paragraph.

4.1 Fisheries Industries

Tsunami has greater impact on fisheries by

colossal damage to fish farming, productivity,

livelihood, import and export, critical fish

infrastructure, ecological unbalance etc. These

expected damages have been witnessed during

Tsunami 2004. The following paragraph discusses about expected impact and

experience of Tsunami 2004 in South-South East Asia.

4.1.1. Fish Farming:

A large segment of coastal society is associated with fisheries and allied industries.

The Tsunami has larger potential to cause damage to fishing accessories. This

includes fishing nets, small boats, medium and large trawlers and other important

tools and equipments.

A large number of fish culture industries including shrimp, Cuttle fish, Jelly Fish

along the coast farming may be badly affected by such events. This problem was

largely observed during Tsunami 2004 along South-South East Asian coast.

Figure 4.1 shows the sea fish losses during Tsunami 2004 in Malaysia.

There is large mass of small fishermen with small trawler, engaged in fish

catching. 2004 Tsunami has witnessed colossal losses to the fisheries industry.

Production sector

influences country GDP and

Economy. Costal production

sector includes fisheries,

agriculture, industry, tourism

etc ..

Tsunami 2004 has

killed about 65 % of

fishermen in Aches capital Banda Ache


38

There was a massive impact to this sector in India, Indonesia, Sri Lanka, Somalia

and Thailand.

In Sri Lanka, twelve of the fourteen coastal districts were severely damaged by the

waves. The population of artisanal fishing in Sri Lanka is represented by the

nearly 700 boat landings along the coast of Sri Lanka. More than 7,500 fishers

were killed by the Tsunami and many thousands are missing, and 80% of the

coastal fishing vessels were completely destroyed. The total damage in the fishery

sector was estimated at $120 million in February. Estimated damage to fisheries

sector in Sri Lanka may be referred at Table 11.

Figure 4.1


39

Table 1: Estimated Damages to the Fisheries Sector from the Tsunami (Source: Post-Tsunami Recovery Program Preliminary Damage and Needs Assessment)

The Tsunami hit coastal part of Thailand accounted for more than 7000 fishermen

boats.

The Aceh region of northern Sumatra in Indonesia was the hardest hit by the

Tsunami. In Aceh's, capital city of Banda Aceh, an estimated 65 % of the local

fishers were killed. In the province of Nanggroe Aceh Darussalam, where 42,000

family fishing fleets had lived, 70% of the small scale fleets have been destroyed.

4.1.2. Productivity and Livelihood

The Tsunami has large potential to affect productivity and livelihood in coastal

area. The livelihood is mostly associated with fisheries, salt production,

transportation, navigation etc. The disruption caused during Tsunami may

largely impact on oceanic product and byproduct, export and import and

associated livelihood in the region.

Tsunami 2004 has witnessed such hardship for productivity and livelihood. In

Sri Lanka, the Tsunami devastated lives, social infrastructure, and economic

foundations. It is estimated that around 200,000 people 2 (3 percent of the

labor force) might have lost their jobs as a result of the Tsunami. This includes


40

100,000 in fisheries; 27,000 employed in tourism and tourism related

activities; and the rest in other informal sector activities. The estimated loss of

output in 2005 and 2006 in the most 2affected sectors (fishing and tourism)

total around 1.5 percent of GDP(Gross Domestic Products), but these sectors

do not make up a significant portion of national GDP.

Similarly Indonesia has witnessed large impact during 2004. The livelihoods

of people in the agricultural sector and fisheries have been hardest hit. An

estimate projected by the World Bank shows that 30 %3 of people killed

during the event were belonging to Fisheries and agriculture. The Figure 4.2

shows that losses in income generating sectors. Among all severe loss was

reported to Agriculture and fisheries. More than 5000 B RP was estimated loss

to this sector.

Figure 4.2: Losses in income generating sectors (Source: PP 77, Preliminary Damage and Loss Assessment CGI January 2005)

c. Import and Export

Severe damage is expected on import and export sector. All port and harbours

are located in coastal areas. The ports and harbours are gateway for import

and export for fisheries and other associated products. The damage may

interrupt the continuity of such process leading to economic losses.

The fish and associated products are perishable by nature. The delay in import

and export may damage the product.


41

Pre Tsunami 2004, The South-Eastern part of India, had number of Shrimp

and Jelly Fish farm. Mainly these aquaculture business was centered for export

and was thus discontinued for longer time leading to unemployment and

economy losses.

4.1.4. Fish Species

The Tsunami may also destroy the aqua eco system. Due to such changes,

there are possibility of threatening many species of fish and other aquatic life.

The Tsunami may change the nature and habits of several species and

reproduction system. Thus leading ecological imbalance in the aquatic region.

4.1.5. Critical Fishery Infrastructure

Apart from negative impact on fisheries, the associated critical infrastructures

are also badly affected. These infrastructure may be boat repairing and

servicing, hatcheries, boat spare part industries and distributaries, warning

communication systems for low and high tides, cyclone warning etc.,

The collapse of critical infrastructure delays the short term and long term

reconstruction and recovery process. The South-South East Asia region has

witnessed his factors during Tsunami 2004.

The Tsunami 2004 has widely impacted to these infrastructures. In India, After

Tsunami more than 50004 boats were badly damaged, causing damage valued

at Rs. 663.1 crore ($152.4 million); a total of 7,933 fiber-reinforced plastic

boats/vallams valued at Rs. 50.1 crore ($11.5 million); about 24,580 boats of

other categories, mainly motorized, valued at Rs. 121.0 crore ($27.8 million);

and 35,483 wooden catamarans valued at Rs. 90.0 crore ($20.7 million). In

addition, 2,342 outboard motors worth Rs. 10.1 crore ($2.3 million) were

damaged or lost. This figure is expected to increase substantially after revision.

Net sets valued at Rs. 44.4 crore ($10.2 million) were damaged or lost. Boat

seines worth Rs. 19.9 crore ($4.6 million) were lost in Kerala. Figure 4.3

shows boats damages during Tsunami.

In recent years, the fisheries sector has been playing an increasingly important

role in the economy uplift efforts of Bangladesh. It is a labour-intensive and


42

quick-yielding sector which augments growth and alleviates poverty. Around

1.3 million people are directly employed in the fisheries sector alone. The

country has immense natural potential for developing the fisheries sub-sector.

The sector contributes 3.3% of the GDP5 and 10.33% of the agriculture sector.

The sector includes open water bodies such as rivers, canals, lakes, etc. The

sector marked a continuous annual growth of 8.6% since 1996. Fish

production increased to over 1 .4 million tons during 1997-98. In view of

importance of this sector and linkage with livelihood, it is necessary to

develop preparedness and establish early warning system for coastal part of

Bangladesh.

Figure 4.3: Boats damaged by Tsunami 2004 (Source. Reuters)

4.2 Agriculture Sector

The Tsunami badly affects coastal agriculture, field crops, perennial / fruit

trees, agriculture tools, irrigation systems and infrastructure, forestry and other

associated business and livelihood.

Coastal areas are growing rubber plantation, Coconut, beetle nuts, several

types of Spices, Cashew nuts and weeds. These can be badly affected during

storm surge and inundations


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Several types of crops predominantly paddy, is grown in coastal areas. The

agriculture sector is affected in several ways. Few of them are as below:

Change of PH of the soil reducing the productivity

Intrusion of salt water in ground water

Overlay of salt layer on arable land

Damage of irrigation infrastructure

Damage to agriculture tools and machines

Massive erosion of arable land

The damage and loss to agriculture sector

due to Tsunami indirectly affect the

productivity, livelihood of villager, small

farmers, helpers associated with

agriculture, import and export and

agriculture product and bye product

processing.

The December 26, 2004, Tsunami in the Indian Ocean threatened much of the

region's agriculture. At least 116,0006 acres of land were damaged by the

Tsunami in Thailand, Sri Lanka, India, Maldives, and Indonesia. Land flooded

with salt water left the soil contaminated with high levels of saline making the

land uncultivable.

Sri Lanka has coastal wetlands that provide cultivation of rice. Other major

crops are tea, rubber and coconut, helping Sri Lanka to stay self sufficient.

About 14 percent5 of Sri Lanka's land is arable, or fit for the use as farmland.

Approximately 2,175 hectares of rice paddies and 1,708 hectares of other

crops were destroyed by the Indian Ocean Tsunami. The salinization of the

land has made it unsuitable for cultivation. Debris has been deposited on the

land as well, and agricultural equipment has been destroyed.

Indonesia's about 11 percent of the land is arable. Agriculture contributes an

estimated 32 percent of the Gross Domestic Product (GDP) of the country.

During Tsunami 2004, approximately 36-50 thousand hectares5 were exposed

Tsunami impacts the

agriculture by changing the

soil properties, damaging

irrigation and agriculture

infrastructure and massive

erosion


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to high salinity levels from sea water, and thousands more are covered in salty

debris. Coastal land hit by the Tsunami lost most of its topsoil. 10-15 percent

of the total cropland has been destroyed. Agricultural equipment and tools

were lost in the Tsunami, irrigation and drainage facilities were destroyed, in

addition to many home gardens.

The climate in the coastal India is influenced by tropical monsoon cycle. The

terrain is mostly flat with few mountains. 54 percent 5 of the land is arable.

The Tsunami damaged approximately 11,827 hectares of cropland through

salinization. Agriculture was relatively important and the disaster will have an

effect on the coastal economy.

Thailands about 29 percent of the land in Thailand is arable, or fit for use as

farmland. About 800 hectares of land 5 was destroyed by the Indian Ocean

Tsunami. Harvesting of the main season rice paddies was underway just

before the Tsunami occurred. The agriculture of the country was not greatly

affected, due to the small amount of farmland the Tsunami reached.

Bangladesh is primarily an agrarian economy. Agriculture is the single largest

producing sector of economy since it comprises about 30% 5of the country's

GDP and employing around 60% of the total labour force. The performance of

this sector has an overwhelming impact on major macroeconomic objectives

like employment generation, poverty alleviation, human resources

development and food security. Bangladesh is the largest producer of Jute.

Rice being the staple food, its production is of major importance. Rice

production stood at 20.3 million tons in 1996-97 fiscal years. The impact of

Tsunami on agriculture sector will be critical and will affect the livelihood,

food and production. It is necessary to develop strategy for reducing the

impact of Tsunami.

4.3 Industry

The coastal industry focuses mainly on marine production, ship manufacture,

allied port production, oil refineries, chemical and industrial production. These

industries are set up in coastal region for better resources and importing raw


45

material and exporting finished products. Apart from these productions, the

region also focuses on fish and other aqua product processing.

Recent development is faster in coastal

region for several reasons. The

development agencies and authorities are

interested to establish special Economy

Zone in such area. The purpose of making

special economic zone is to place all

industrial units together. If the region is

prone to Tsunami, the losses will be very

high in such region.

The Tsunami hits the coast and affect in several ways. The reasons to damage

physical infrastructure may be follows:

o Ground shaking due to earthquake

o Liquefaction and other collateral hazards due to ground shaking

o Storm Surge

o Lateral forces of sea waves / water column shitting the buildings

and infrastructure

o Inundation due to storm surge

o Hitting by floating debris

o Runoffs

The Tsunami 2004 has damaged large industrial elements. The large

devastation was seen in Banda Ache in Indonesia, Tamil Nadu, India, North

East part of Sri Lanka. The damage has been reported to small scale to

medium scale industries. These industries are usually linked to coastal

commercial and business systems.

Since Tsunami directly impacts industrial infrastructure, leading to reduction

of productivity. The revenue losses shoots up and there is discontinuity in

production. This adversely impacts the exporting goods.

Coastal industrial

infrastructure is much

vulnerable to Tsunami waves.

The damage to such

infrastructure will lead to losses

of livelihood, industrial export

and import and future

development


46

The damage to critical and hazardous production industry further aggravates

the disaster situation. This may be possible in case of hazardous chemical

industries, Oil Refineries and fertilizer companies. The leakage of chemicals

or toxic substances may lead to intoxication, fire or explosions. The release of

hazardous substances may lead to hindrances in response and relief too.

Salt production and processing is one of the biggest industries in the coast

region. The seawater intake system, drying units, ponds may be affected by

inundation and gushing water column. A large segment of community is

linked to salt production along the sea coast, leading to unemployment and

economic burden.

Bangladesh has 7a good number of large, medium and small-sized industries in

both public and private sectors based on both indigenous and imported raw

materials. Among them are jute, cotton, textile, fertilizer, engineering,

shipbuilding, steel, oil-refinery, paper, newsprint, sugar, chemicals, cement

and leather. Jute Industry has traditionally played an important role in the

national economy. But in recent years, Ready Made Garments Industry has

replaced Jute as the principal export-earner for the country. Considerable

progress has been attained in the past few years in industries such as leather,

ceramic, shrimp, fish, pharmaceuticals and frozen food.

With the development of infrastructures, supportive policies for trade and

investment and comparative advantage in labour-intensive Industries,

excellent prospects for investment exist in Bangladesh today. Industrial

growth was recorded at 81% during 1997-98. Foreign investors are pouring

into the country in greater numbers ever day, especially in the export

processing zones special facilities existing at Dhaka and Chittagong.

To attract local and foreign investors, the present government has introduced a

number of perks and incentives. These include provision for setting up export

processing zones in the private sector, initiatives to set up new EPZs in the

public sector, tax holiday for export-oriented industries, scope for 100 percent

foreign investments and repatriation of profits. In view of concentration of

industrial development in coastal areas, it is necessary to develop strategy for

loss reduction caused by probable Tsunami.


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4.4 Tourism

Sea coast provides abundant opportunity for tourism to the country. Good

beaches, hotel, resorts, aqua sport creates avenues for commercial and

economic growth. This is the reason for tourism development in several

countries like Thailand, Indonesia, Malaysia, Maldives, Sri Lanka, India,

Bangladesh and other coastal countries. Figure 4.4 shows the impact of

Tsunami on Tourism in Thailand.

The Tsunami impacts the tourism in following ways

o Inundation of beaches and natural terrain

o Fear psychosis of the tourists about the potential hazards

o Damage to physical infrastructure like hotels, resorts, restaurants, clubs

and entertainment spots due to earthquake and collateral hazards along

with storm surge and inundation

o Poor infrastructure in affected region retards the inflow of tourist.

o Damage to historic monuments

o The primary or secondary elements of tourism like hotel industries,

restaurants, entertainment shows are badly affected thus live becomes

miserable to the people dependent.

Figure 4.4: Damage to Tourism in Thailand during Tsunami 2004 (Source http://www.un.or.th/Tsunamiinthailand/Tsunami2004anditsimpact.html )


48

The Tsunami that hit several countries in Asia and Africa resulted in extensive

asset losses for the tourism sector (250 million). About $200 million damages

to hotel rooms was sustained and $50 million in tourism related assets

(souvenir shops, restaurants, vehicles).

In Sri Lanka, the tourism sector is

estimated to contribute 2 to 4 percent of

GDP including direct and indirect effects.

It generates direct employment for about

50,000 people and indirect employment

for an additional 65,000, and over $350

million in foreign exchange earnings. The tourism sector started to pick up

following the cease-fire and peace negotiations in 2002 reaching a historical

record of 565,000 arrivals in 2004.

About 50 hotels were partially damaged and 8 hotels were fully damaged of

the 105 hotels located in the Tsunami affected areas and total 242 registered

hotels in Sri Lanka. In terms of rooms 3,500 out of the total 14,000 rooms in

medium to large s