Unit 1: Disaster Introduction, Definitions and Classification
Syllabus & Past Papers
Unit - I: Introduction, Definitions and Classification
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Disaster
Centre for Research on the Epidemiology of Disasters (CRED) defines a disaster as “a situation or event [which] overwhelms local capacity, necessitating a request to a national or international level for external assistance; an unforeseen and often sudden event that causes great damage, destruction and human suffering.”
Disaster means a catastrophe, mishap, calamity or grave occurrence in any area, arising from natural or man-made causes, or by accident or negligence which results in substantial loss of life or human suffering or damage to, and destruction of, property, or damage to, or degradation of, environment, and is of such a nature or magnitude as to be beyond the coping capacity of the community of the affected area (definition according to Disaster Management Act 2005, Government of India).
a disaster can also be defined as - A serious disruption of the functioning of a society, causing widespread human, material, or environmental losses which exceed the ability of the affected society to cope using its own resources. The term disaster is sometimes also used to describe a catastrophic situation in which the normal patterns of life (or ecosystems) have been disrupted and extraordinary, emergency interventions are required to save and preserve human lives and/or the environment. Disasters are frequently categorized according to their perceived causes and speed of impact.
Capacity
Capacity (as contrasted to vulnerability) has been included in disaster management initially as a guide for both international and local agencies who work with vulnerable communities to link disaster to development – even in emergency situations disaster survivors have capacities. They are not helpless victims but have ‘coping’ mechanisms on which to build on for emergency response and recovery. For many vulnerable groups, the viable track to reduce vulnerabilities has been by increase their social and organization capacities are resources means and strengths. These exist in households and communities and enable them to withstand, prepare for, event, mitigate, or quick recovery from a disaster. People’s capacity can also be categorized in the same categories as was done with vulnerabilities in the previous section.
Physical and Material Capacity:
When the people whose houses have been developed by a typhoon and crops, destroyed by a flood can salvage things from their homes and from their farms. Sometimes they have food in storage or crops that can be recovered from the fields or farm implements for planning again. Some family members have skills, which enable them to find employment if they migrate, either temporarily or permanently.
Social and Organizational Capacity
When everything physical is destroyed, people still have their skills and knowledge; they have family and community organization. They have leaders and systems for making decisions. They have tribal loyalties or church affiliations. They have capacities within the social and organizational realm.
Attitudinal and Motivational Capacity
People also have positive attitudes and strong motivations such as the will to survive, love and concern for each other, bravery and willingness to help each other. These, too, are important capacities and from the basis for development just as much as the physical resources that people have.
Risk
Risk analysis is an integral part of the field of business and finance. In disaster management, applied scientists initially developed risk studies to project probable disaster loss and to determine which scientific and technical solutions were to be applied either to modify the hazard or modify physical vulnerability to the hazard. Risk is commonly used to mean the probability or likelihood of meeting danger or suffering harm and loss. Risk is sometimes taken as synonymous with hazard but risk has an additional implication of the chance of a particular hazard actually occurring. It is also the exposure of something of human value (life, property, and the environment) to a hazard and is often regarded as the combination of probability and loss.
Hazard,
HAZARD is any substance, phenomenon or situation, which has the potential to cause disruption or damage to people, their property, their services and their environment.
A dangerous phenomenon, substance, human activity or condition that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage. Hazards arise from a variety of geological, meteorological, hydrological, oceanic, biological, and technological sources, sometimes acting in combination. In technical settings, hazards are described quantitatively by the likely frequency of occurrence of different intensities for different areas, as determined from historical data or scientific analysis.
Hazard- A rare extreme natural or human made event that threatens to adversely affect human life, property or activity to the extent of causing disaster. A hazard is a natural or man-made phenomenon which may cause physical damage, economic losses, or threaten human life and well being if it occurs in an area of human settlement, agricultural, or industrial activity. Hazard is an event or occurrence that has the potential for causing injuries to life and damaging property and the environment. Examples of natural hazards are typhoons, tsunamis, earthquake and volcanic eruption, which are exclusively of natural origin. Landslides, floods, drought, fires are social –natural hazard since their causes are both natural and management-made. More and more, the distinction between natural and management-made hazards is becoming harder to delineate. For example; storm surge hazard may be worsened by the destruction of mangroves. Human-made hazards are associated with industries or energy generation facilities and include explosions, leakage of toxic waste, pollution, dam failures, war or civil strife is included in this category. An example of concatenated hazards is an earthquake causing landslides, which dams a river and then causes flooding. A community may be exposed to multiple hazards when there is simultaneous occurrence of different hazards.
Natural hazard
Natural process or phenomenon that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage. Natural hazards are a sub-set of all hazards. The term is used to describe actual hazard events as well as the latent hazard conditions that may give rise to future events. Natural hazard events can be characterized by their magnitude or intensity, speed of onset, duration, and area of extent. For example, earthquakes have short durations and usually affect a relatively small region, whereas droughts are slow to develop and fade away and often affect large regions. In some cases hazards may be coupled, as in the flood caused by a hurricane or the tsunami that is created by an earthquake.
Technological hazards
A hazard originating from technological or industrial conditions, including accidents, dangerous procedures, infrastructure failures or specific human activities, that may cause loss of life, injury, illness or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage. Examples of technological hazards include industrial pollution, nuclear radiation, toxic wastes, dam failures, transport accidents, factory explosions, fires, and chemical spills. Technological hazards also may arise directly as a result of the impacts of a natural hazard event.
Vulnerability
The characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard. There are many aspects of vulnerability, arising from various physical, social, economic, and environmental factors. Examples may include poor design and construction of buildings, inadequate protection of assets, lack of public information and awareness, limited official recognition of risks and preparedness measures, and disregard for wise environmental management. Vulnerability varies significantly within a community and over time. This definition identifies vulnerability as a characteristic of the element of interest (community, system or asset) which is independent of its exposure. However, in common use the word is often used more broadly to include the element’s exposure.
Vulnerability- Vulnerability is a set of prevailing or consequential conditions that adversely affect people’s ability prevent, mitigate, prepare for and respond to hazardous events. These long-term factors, weaknesses or constraints affect a household or community’s ability (or inability) also to absorb losses after disaster or to recover from the damage. Vulnerabilities precede disasters contribute to their severity, impede disaster response, and may continue to exists long after a disaster has stuck. Anderson and Woodrow (1990) categorize vulnerability into three areas namely:
• Physical/ Material Vulnerability: For example, poor people who have few physical/ material resources usually suffer more from disaster than rich people. People who are poor often live on marginal lands; they don’t have any savings or insurance; they are in poor health. These factors make them more vulnerable to disaster and mean that they have harder time surviving and recovering from a calamity than people who are better off economically.
• Social/Organizational: Experience shows that people who have been ‘marginalized’ in social, economic or political terms are vulnerable to suffering from disasters whereas groups which are well organized and in which there is a high commitment to each other suffer less when catastrophe strikes. For example, deep divisions can lead to conflict and war. Conflict or resources due to poverty can also lead to violence. A second area of vulnerability then, is the social/organizational and economic realm.
• Attitude and Motivational Vulnerability - Experience also shows that the people who do not have confidence in their ability to affect change and feel defeated by events they can not control, are harder hit by disasters. This is in contrast to those who have a sense of their ability to bring about the changes they desire.
Vulnerability
The extent to which a community, structure, service, or geographic area is likely to be damaged or disrupted by the impact of a particular disaster hazard, on account of their nature, construction, and proximity to hazardous terrain or a disaster prone area.
For engineering purposes, vulnerability is a mathematical function defined as the degree of loss to a given element at risk, or set of such elements, expected to result from the impact of a disaster hazard of a given magnitude. It is specific to a particular type of structure, and expressed on a scale of 0 “high,” “medium,” and “low” or explicit statements concerning the disruption likely to be suffered.
Coping capacity
The ability of people, organizations and systems, using available skills and resources, to face and manage adverse conditions, emergencies or disasters. The capacity to cope requires continuing awareness, resources and good management, both in normal times as well as during crises or adverse conditions. Thus, the combination of all the strengths, attributes and resources available within a community, society or organization that can be used to achieve agreed goals is termed as its capacity. It may include infrastructure and physical means, institutions, societal coping abilities, as well as human knowledge, skills and collective attributes such as social relationships, leadership and management.
Resilience
Risks
The combination of the probability of an event and its negative consequences. The word “risk” has two distinctive connotations: in popular usage the emphasis is usually placed on the concept of chance or possibility, such as in “the risk of an accident”; whereas in technical settings the emphasis is usually placed on the consequences, in terms of “potential losses” for some particular cause, place and period. It can be noted that people do not necessarily share the same perceptions of the significance and underlying causes of different risks.
Risk management
The systematic approach and practice of managing uncertainty to minimize potential harm and loss. Risk management comprises risk assessment and analysis, and the implementation of strategies and specific actions to control, reduce and transfer risks. It is widely practiced by organizations to minimize risk in investment decisions and to address operational risks such as those of business disruption, production failure, environmental damage, social impacts and damage from fire and natural hazards. Risk management is a core issue for sectors such as water supply, energy and agriculture whose production is directly affected by extremes of weather and climate.
Natural disasters:
Cloud bursts,
Earth quakes
Tsunami
Snow avalanches
Landslides
Forest fires
Diversion of river routes (ex. Kosi river)
Man-Induced Disasters
Floods
Flooding is a natural and inevitable part of our weather cycle. While it will always happen in cities like Melbourne, we aim to minimize the risk to people, property and infrastructure.
Droughts
Rain fall trend in the past 20 years
Cyclones
Volcanic hazards
Disasters (Mud volcanoes): Causes and Distribution
A volcanic hazard refers to any potentially dangerous volcanic process (e.g. lava flows, pyroclastic flows, ash). A volcanic risk is any potential loss or damage as a result of the volcanic hazard that might be incurred by persons, property, etc. or which negatively impacts the productive capacity/sustainability of a population. Risk not only includes the potential monetary and human losses, but also includes a population's vulnerability. The definitions of hazard and risk are not well-defined. For a more complete discussion of the definitions
Types of Volcanic Hazards
The following is a list of volcanic hazards. Click on the one that you are interested in learning about.
Debris Avalanches, Landslides, and Tsunamis
Hazards Prevention
In recent years, many advances have been made in the study of volcanoes particularly in eruption prediction. The problem with volcanoes is that, though there may be similarities between volcanoes, every volcano behaves differently and has its own set of hazards. Many active volcanoes near populated areas have not been sufficiently studied to assess risk.
By studying volcanic deposits, scientists can produce hazard maps. These maps indicate the types of hazards that can be expected in a given area the next time a volcano erupts. Dating of these volcanic deposits helps determine how often an eruption may occur and the probability of an eruption each year. Monitoring of a volcano over long periods of time will indicate changes in the volcano before it erupts. These changes can help in predicting when an eruption may occur.
Figure 1Kīlauea's lava entering the sea
Hazardous effects and environmental impacts of Natural Disasters
The forces of the natural world can cause significant risk to life, property and economies. The power of extreme weather events and geological movements can alter the status quo in sudden dramatic actions. Natural risk includes flooding and mudflow, landslides, avalanches, droughts and fires and coastal realignment.
Industrialization has created additional stresses on the capacity of natural systems to recycle and regenerate, leading to a different set of environmental risk. Aspects of this research area include understanding resilience of natural systems and modelling the uncertainties associated with risk management strategies.
Societal impact and strategic research objectives
There are immense impacts of natural hazards and environmental risk on society and its economies. In addition to major loss of life there are huge economic costs in terms of destroyed infrastructure, and immediate and long-term relief. The goal of the research is to understand and assess causes, risks and effects, and then to examine management and mitigation strategies. Moreover, as climate change and land use change occurs, it will be important to determine consequential change in natural hazards risk.
Political and administrative framework
The development of harmonized EU-wide methodologies and information systems for the prevention and prediction of weather-driven natural hazards is important to optimize the support and exchange expertise. This is designed to complement national and local initiatives.
Read more on natural hazards on JRC home page: http://ies.jrc.ec.europa.eu/the-institute/units/climate-risk-management.html
Main sub-fields and areas
Floods
Mudflows
Droughts
Mass movements
Avalanches
Forest fires
Earthquakes and tsunamis
Volcanoes
Air pollution
Water pollution
Approach
Natural hazards research requires a robust and comprehensive framework that links individual hazard and multi-hazards research with the integration of the risk-reduction chain. This includes understanding, modelling, forecasting natural systems and events and a thorough risk analysis of exposure and vulnerability with particular attention to the multi-risk dimension. This approach is necessary for risk management as well as for developing prevention and mitigation strategies.
Earthquakes, floods and landslides, etc. are natural environmental hazards of disastrous consequences.
In recent years these hazards took toll of thousands of lives and caused massive destruction of property.
These have adversely affected the vital sectors of our development as agriculture, communication, irrigation, power projects and rural and urban settlements.
Mitigation measures
Natural disaster prone areas in India
Floods and droughts significantly impact the majority of India though they are most prevalent in the northwestern and eastern regions respectively. Geophysical hazards affect the Himalayan region in the north and northeastern portions of the country where they rank in high deciles for mortality and lower deciles for GDP impact.
Cyclones influence a relatively small area of the country but have high-ranking mortality and GDP weighted impacts. Lastly, both the multi-hazard mortality and GDP maps demonstrate that almost the entire country is significantly impacted by at least one hazard and mortality impacts are particularly concentrated in the north and northeastern regions.
Major natural disasters in India with special reference to Uttarakhand.
Man-Induced Disasters:
Water logging
Subsidence
Ground Water Depletion
Soil Erosion
Release of toxic gases and hazardous chemicals into environment
Nuclear explosions
Exercises
MCQs
a) Which of the following is not part of geological disaster?
(i) Volcanoes (ii) Earthquakes
(iii) Tsunami (iv) Sea Surge
b) What causes Tsunami?
(i) Sudden vertical movement of the Earth
(ii) Convergence of destructive plates in the ocean floor
(iii) Explosive volcanic eruptions in the seas/oceans.
(iv) All of the above
c) Which of the following is not a natural disaster?
(i) Nuclear explosion (ii) Deforestation
(iii) Forest fire (iv) Lightning
d) Cyclone is a _________
(i) Hazard (ii) Boon
(iii) Growth phenomena (iv) Problem
e) Geothermal energy is generated from ________
(i) Volcanoes (ii) Earthquakes
(iii) Floods (iv) Land slides
a) What is the reason for volcanic eruption?
(i) Movement and splitting of the major and minor plates of the Earth
(ii) Origin of magma because of lowering of melting point inside the Earth caused by reduction in the pressure due to the splitting of plates and their movements in opposite directions.
(iii) Only A
(iv) Both A & B
b) The word Tsunami has been derived from _________
(i) Tamil (ii) French
(iii) Japanese (iv) Latin
c) Avalanches take place in …
(i) High altitudes (ii) Low latitudes
(iii) Ground level (iv) Beneath the ocean
d) Vagaries of monsoon cause ___________.
(i) Floods (ii) Volcanoes
(iii) Earthquakes (iv) Avalanches
e) In India Tsunami warning Centre is located at ________
(i) Hyderabad (ii) Ahmedabad
(iii) Allahabad (iv) Secunderabad
Descriptive Questions
What is disaster? What are the various types of Disasters?
What is a Hazard? How is it classified?
Write down the different forms of natural disasters.
List and explain the slow onset natural disasters.
Discuss the probability and impacts of the Natural and Manmade disasters in India.
Explain with examples the difference between hazard, and vulnerability. How does capacity influence vulnerability?
What are landslides? List out major causes of landslides in India.
Explain the disasters caused by the irregular water cycle.
Why is drought a slow onset disaster? Identify five factors that cause drought.
What are the causes of Earthquakes? Discuss the measures to mitigate the impact of this disaster.
What are earthquakes? List out the causes of an earthquake.
What is Tsunami? Identify three causes, consequences and impact of tsunami waves.
Discuss the measures to mitigate the impact of cyclone.
Explain the characteristics of a cyclone. Identify risk reduction measures for cyclones.
Reviewed by Green Voice India
on
March 06, 2021
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