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Natural Hazards & Disaster Management

Natural Hazards & Disaster Management

Chapter 1

INTRODUCTION TO DISASTER MANAGEMENT

Objectives of the chapter:

Background:

The main objective of this chapter is to

have a basic understanding of various

concepts used in Disaster Management.

The concepts explained here are:

Disaster, Hazard, Vulnerability, Capacity,

Risk and Disaster Management Cycle.

Apart from the terminologies, the chapter

also tries to explain various types of

disasters. In standard VIII, IX and X

many of you have already been

introduced to some of these concepts.

This chapter has been designed

to upgrade your knowledge and skill

so as to have a better understanding of

natural hazards, disasters and their

management.

After reading this chapter the

students and the teachers will be

able to have a basic understanding

of the concepts and should be able

to differentiate between them with

suitable examples.

The global context:

Disasters are as old as human history but

the dramatic increase and the damage

caused by them in the recent past have

become a cause of national and international

concern. Over the past decade, the number

of natural and manmade disasters has

climbed inexorably. From 1994 to 1998,

reported disasters average was 428 per year

but from 1999 to 2003, this figure went up to

an average of 707 disaster events per year

showing an increase of about 60 per cent

over the previous years. The biggest rise was

in countries of low human development,

which suffered an increase of 142 per cent.

The figure 1.1 shows the deadliest disasters

of the decade (1992 – 2001). Drought and

famine have proved to be the deadliest

disasters globally, followed by flood,

technological disaster, earthquake, winds-

torm, extreme temperature and others. Global

economic loss related to disaster events

average around US $880 billion per year.

Fig : 1.1 World Scenario: Reported Deaths from all

Disasters (1992-2001)

Natural Hazards & Disaster Management

Indian scenario:

The scenario in India is no different from

the global context. The super cyclone of

Orissa (1999), the Gujarat earthquake

(2001) and the recent Tsunami (2004)

affected millions across the country

leaving behind a trail of heavy loss of life,

property and livelihood. Table 1.1 shows

a list of some of the major disasters that

have caused colossal impact on the

community.

Table 1.1 Major disasters in India since 1970

Sl. No

Disaster

Cyclone

29th October 1971, Orissa

19th November, 1977,

Andhra Pradesh

29th and 30th October 1999,

Orissa

Earthquake

20th October 1991 Uttarkashi

30th September 1993 Latur

22 May 1997 Jabalpur

29th March 1997, Chamoli

26th January, 2001, Bhuj,

Gujarat

Landslide

July 1991, Assam

August 1993, Nagaland

18th August 1998, Malpa

Flood

1978 Floods in North East India

1994 Floods in Assam,

Arunachal Pradesh, Jammu and

Kashmir, Himachal Pradesh,

Panjab, Uttar Pradesh, Goa,

Kerala and Gujarat

Impact

Cyclone and tidal waves killed 10,000

people

Cyclone and tidal waves killed 20,000

people

Cyclone and tidal waves killed 9,000 and

18 million people were affected

An earthquake of magnitude 6.6 killed

723 people

Approximately 8000 people died and

there was a heavy loss to infrastructure

39 people dead

100 people dead

More than 10,000 dead and heavy loss

to infrastructure

300 people killed, heavy loss to roads

and infrastructure

500 killed and more than 200 houses

destroyed and about 5kms. Road

damaged.

210 people killed. Villages were washed

away

3,800 people killed and heavy loss to

property.

More than 2000 people killed and

thousands affected

Natural Hazards & Disaster Management

While studying about the impact we need to

be aware of potential hazards, how, when

and where they are likely to occur, and the

problems which may result of an event. In

India, 59 per cent of the land mass is

susceptible to seismic hazard; 5 per cent of

the total geographical area is prone to floods;

8 per cent of the total landmass is prone to

cyclones; 70 per cent of the total cultivable

area is vulnerable to drought. Apart from this

the hilly regions are vulnerable to avalanches/

landslides/hailstorms/cloudbursts. Apart from

the natural hazards, we need to know about

the other manmade hazards which are

frequent and cause huge damage to life and

property. It is therefore important that we are

aware of how to cope with their effects.

We have seen the huge loss to life, property

and infrastructure a disaster can cause but

let us understand what is a disaster, what

are the factors that lead to it and its impact.

What is a Disaster ?

Almost everyday, newspapers, radio and

television channels carry reports on disaster

striking several parts of the world. But what

is a disaster? The term disaster owes its

origin to the French word “Desastre” which

is a combination of two words ‘des’ meaning

bad and ‘aster’ meaning star. Thus the term

refers to ‘Bad or Evil star’. A disaster can

be defined as “A serious disruption in the

functioning of the community or a society

causing wide spread material, economic,

social or environmental losses which exceed

the ability of the affected society to cope

using its own resources”.

A disaster is a result from the combination

of hazard, vulnerability and insufficient

capacity or measures to reduce the potential

chances of risk.

A disaster happens when a hazard impacts

on the vulnerable population and causes

damage, casualties and disruption. Fig: 1.2

would give a better illustration of what a

disaster is. Any hazard – flood, earthquake

or cyclone which is a triggering event along

with greater vulnerability (inadequate access

to resources, sick and old people, lack of

awareness etc) would lead to disaster

causing greater loss to life and property. For

example; an earthquake in an uninhabited

desert cannot be considered a disaster, no

matter how strong the intensities produced.

Fig: 1.2

Natural Hazards & Disaster Management

An earthquake is disastrous only when it

affects people, their properties and activities.

Thus, disaster occurs only when hazards

and vulnerability meet. But it is also to be

noted that with greater capacity of the

individual/community and environment to

face these disasters, the impact of a hazard

reduces. Therefore, we need to understand

the three major components namely hazard,

vulnerability and capacity with suitable

examples to have a basic understanding of

disaster management.

What is a Hazard ? How is it clas-

sified ?

Hazard may be defined as “a dangerous

condition or event, that threat or have the

potential for causing injury to life or damage

to property or the environment.” The word

‘hazard’ owes its origin to the word ‘hasard’

in old French and ‘az-zahr’ in Arabic

meaning ‘chance’ or ‘luck’. Hazards can be

grouped into two broad categories namely

natural and manmade.

1. Natural hazards are hazards which are

caused because of natural phenomena

(hazards with meteorological, geological or

even biological origin). Examples of natural

hazards are cyclones, tsunamis, earth-

quake and volcanic eruption which are

exclusively of natural origin. Landslides,

floods, drought, fires are socio-natural

hazards since their causes are both natural

and man made. For example flooding may

be caused because of heavy rains, landslide

or blocking of drains with human waste.

2. Manmade hazards are hazards which

are due to human negligence. Manmade

hazards are associated with industries or

energy generation facilities and include

explosions, leakage of toxic waste, pollution,

dam failure, wars or civil strife etc.

The list of hazards is very long. Many occur

frequently while others take place

occasionally. However, on the basis of their

genesis, they can be categorized as

follows:

Table 1.2: Various types of hazards

Types

Geological Hazards

Water & Climatic Hazards

Environmental Hazards

Biological

Hazards

1. Earthquake

2. Tsunami

3. Volcanic eruption

1. Tropical Cyclone

2. Tornado and Hurricane

3. Floods

4. Drought

5. Hailstorm

1. Environmental pollutions

2. Deforestation

1. Human / Animal Epidemics

2. Pest attacks

4. Landslide

5. Dam burst

6. Mine Fire

6. Cloudburst

7. Landslide

8. Heat & Cold wave

9. Snow Avalanche

10. Sea erosion

3. Desertification

4. Pest Infection

3. Food poisoning

4. Weapons of Mass

Destruction

Natural Hazards & Disaster Management

Types

Chemical, Industrial and

Nuclear Accidents

Accident related

Hazards

1. Chemical disasters

2. Industrial disasters

1. Boat / Road / Train

accidents / air crash

Rural / Urban fires

Bomb /serial bomb

blasts

2. Forest fires

3. Oil spills/Fires

4. Nuclear

3. Building collapse

4. Electric Accidents

5. Festival related

disasters

6. Mine flooding

What is vulnerability ?

Vulnerability may be defined as “The extent

to which a community, structure, services

or geographic area is likely to be damaged

or disrupted by the impact of particular

hazard, on account of their nature,

construction and proximity to hazardous

terrains or a disaster prone area.”

Vulnerabilities can be categorized into

physical and socio-economic vulnerability.

Physical Vulnerability: It includes notions of

who and what may be damaged or

destroyed by natural hazard such as earth-

quakes or floods. It is based on the physical

condition of people and elements at risk,

such as buildings, infrastructure etc; and their

proximity, location and nature of the hazard.

It also relates to the technical capability of

building and structures to resist the forces

acting upon them during a hazard event.

Figure 1.3 shows the settlements which are

located in hazardous slopes. Many landslide

and flooding disasters are linked to what you

see in the figure 1.3. Unchecked growth of

settlements in unsafe areas exposes the

people to the hazard. In case of an earth-

quake or landslide the ground may fail and

the houses on the top may topple or slide

and affect the settlements at the lower level

even if they are designed well for earthquake

forces.

Socio-economic Vulnerability: The degree

to which a population is affected by a hazard

Figure 1.3 : Site after pressures from population growth and urbanization

Natural Hazards & Disaster Management

will not merely lie in the physical components

of vulnerability but also on the socio-

economic conditions. The socio-economic

condition of the people also determines the

intensity of the impact. For example, people

who are poor and living in the sea coast don’t

have the money to construct strong concrete

houses. They are generally at risk and

loose their shelters when ever there is

strong wind or cyclone. Because of their

poverty they too are not able to rebuild their

houses.

safe areas and their houses are built with

stronger materials. However, even when

everything is destroyed they have the

capacity to cope up with it.

Hazards are always prevalent, but the

hazard becomes a disaster only when there

is greater vulnerability and less of capacity

to cope with it. In other words the frequency

or likelihood of a hazard and the vulnerability

of the community increases the risk of being

severely affected.

What is capacity ?

What is risk ?

Capacity can be defined as “resources,

means and strengths which exist in

households and communities and which

enable them to cope with, withstand,

prepare for, prevent, mitigate or quickly

recover from a disaster”. People’s capacity

can also be taken into account. Capacities

could be:

Physical Capacity: People whose houses

have been destroyed by the cyclone or crops

have been destroyed by the flood can

salvage things from their homes and from

their farms. Some family members have

skills, which enable them to find employment

if they migrate, either temporarily or

permanently.

Socio-economic Capacity: In most of the

disasters, people suffer their greatest losses

in the physical and material realm. Rich

people have the capacity to recover soon

because of their wealth. In fact, they are

seldom hit by disasters because they live in

Risk is a “measure of the expected losses

due to a hazard event occurring in a given

area over a specific time period. Risk is a

function of the probability of particular

hazardous event and the losses each

would cause.” The level of risk depends

upon:

y Nature of the hazard

y Vulnerability of the elements which are

affected

y Economic value of those elements

A community/locality is said to be at ‘risk’

when it is exposed to hazards and is

likely to be adversely affected by its

impact. Whenever we discuss ‘disaster

management’ it is basically ‘disaster risk

management’. Disaster risk management

includes all measures which reduce disaster

related losses of life, property or assets by

either reducing the hazard or vulnerability

of the elements at risk.

Natural Hazards & Disaster Management

Disaster Risk Reduction can take place in the following ways:

1. Preparedness

This protective process embraces measures which enable governments, communities

and individuals to respond rapidly to disaster situations to cope with them effectively.

Preparedness includes the formulation of viable emergency plans, the development

of warning systems, the maintenance of inventories and the training of personnel.

It may also embrace search and rescue measures as well as evacuation plans for

areas that may be at risk from a recurring disaster.

Preparedness therefore encompasses those measures taken before a disaster event

which are aimed at minimising loss of life, disruption of critical services, and damage

when the disaster occurs.

2. Mitigation

Mitigation embraces measures taken to reduce both the effect of the hazard and the

vulnerable conditions to it in order to reduce the scale of a future disaster. Therefore

mitigation activities can be focused on the hazard itself or the elements exposed to

the threat. Examples of mitigation measures which are hazard specific include water

management in drought prone areas, relocating people away from the hazard prone

areas and by strengthening structures to reduce damage when a hazard occurs.

In addition to these physical measures, mitigation should also aim at reducing the

economic and social vulnerabilities of potential disasters

Disaster Management Cycle

Disaster Risk Management includes sum

total of all activities, programmes and

measures which can be taken up before,

during and after a disaster with the purpose

to avoid a disaster, reduce its impact or

recover from its losses. The three key stages

of activities that are taken up within disaster

risk management are:

1. Before a disaster (pre-disaster).

Activities taken to reduce human and

property losses caused by a potential

hazard. For example carrying out aware-

ness campaigns, strengthening the existing

weak structures, preparation of the disaster

management plans at household and

community level etc. Such risk reduction

measures taken under this stage are termed

as mitigation and preparedness activities.

2. During a disaster (disaster

occurrence).

Initiatives taken to ensure that the needs and

provisions of victims are met and suffering is

minimized. Activities taken under this stage

are called emergency response activities.

3. After a disaster (post-disaster)

Initiatives taken in response to a disaster

with a purpose to achieve early recovery and

rehabilitation of affected communities,

immediately after a disaster strikes. These are

called as response and recovery activities.

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Reference: Are you prepared? Learning from the Great Hanshin-Awaji

Earthquake Disaster - Handbook for Disaster Reduction and Volunteer activities

Figure 1.4 : Disaster Management

In the subsequent chapters we would

discuss in detail some of the major hazards

prevalent in our country its causes, impact, 3.

preparedness and mitigation measures that

need to be taken up.

Reference for further reading:

Reading materials of 11th Community Based 5.

Disaster Risk Management Course,

Bangkok, Thailand July 21 – August 1, 2003.

Anderson, M. and P. Woodrow. 1989. Rising 6.

from the Ashes: Development Strategies in

Times of Disaster. UNESCO and West view

Press, Inc., Colorado.

Anderson M. Vulnerability to Disaster and

Sustainable Development: A General

Framework for Assessing Vulnerability.

UNDP Disaster Management Training

Programme.1992. An Overview of Disaster

Management.

International Federation of Red Crescent

Societies World Disaster Report: Focus on

Community resilience.

http://www.unisdr.org/eng/library/lib-

terminology

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Exercise

1) Explain with examples the difference

between hazard, and vulnerability. How

does capacity influence vulnerability? 4)

2) Explain in detail the vulnerability

profile of our country.

Define risk and suggest two ways of

reducing risk with appropriate

examples.

Briefly discuss the Disaster

Management Cycle with suitable

examples.