Definition, Introduction to natural and manmade disaster, Levels of disasters, History on natural disasters in India, Disaster phenomena and events (global national and regional), Concept of risk, hazard, and vulnerability)

A disaster is a serious disruption, occurring over a relatively short time, of the functioning of a community or a society involving widespread human, material, economic or environmental loss and impacts, which exceeds the ability of the affected community or society to cope using its own resources.

In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazards and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as in the case of uninhabited regions.

Developing countries suffer the greatest costs when a disaster hits – more than 95 percent of all deaths caused by hazards occur in developing countries, and losses due to natural hazards are 20 times greater (as a percentage of GDP) in developing countries than in industrialized countries

The word disaster is derived from Middle French désastre and that from Old Italian disastro, which in turn comes from the Ancient Greek pejorative prefix δυσ-, (dus-) "bad" and ἀστήρ (aster), "star".

The root of the word disaster ("bad star" in Greek) comes from an astrological sense of a calamity blamed on the position of planets.

Researchers have been studying disasters for more than a century, and for more than forty years disaster research. The studies reflect a common opinion when they argue that all disasters can be seen as being human-made, their reasoning being that human actions before the strike of the hazard can prevent it developing into a disaster. All disasters are hence the result of human failure to introduce appropriate emergency management measures.

Hazards are routinely divided into natural or human-made, although complex disasters, where there is no single root cause, are more common in developing countries. A specific disaster may spawn a secondary disaster that increases the impact. A classic example is an earthquake that causes a tsunami, resulting in coastal flooding.

Natural disasters

A natural disaster is a 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.

Various phenomena like earthquakes, landslides, volcanic eruptions, floods, hurricanes, tornadoes, blizzards, tsunamis, and cyclones are all natural hazards that kill thousands of people and destroy billions of dollars of habitat and property each year. However, the rapid growth of the world's population and its increased concentration often in hazardous environments has escalated both the frequency and severity of disasters. With the tropical climate and unstable landforms, coupled with deforestation, unplanned growth proliferation, non-engineered constructions make the disaster-prone areas more vulnerable. Developing countries suffer more or less chronically from natural disasters due to ineffective communication combined with insufficient budgetary allocation for disaster prevention and management

Man-made disasters

Human-instigated disasters are the consequence of technological or human hazards. Examples include stampedes, fires, transport accidents, industrial accidents, oil spills, nuclear explosions/nuclear radiation. War and deliberate attacks may also be put in this category. Other types of man-made disasters include the more cosmic scenarios of catastrophic global warming, nuclear war, and bioterrorism.

Levels of Disasters:

Level-L1: The level of disaster that can be managed within the capabilities and resources at the District level. However, the state authorities will remain in readiness to provide assistance if needed;

Level-L2: This signifies the disaster situations that require assistance and active mobilization of resources at the state level and deployment of state level agencies for disaster management. The central agencies must remain vigilant for immediate deployment if required by the state; and

Level-L3: This corresponds to a nearly catastrophic situation or a very large-scale disaster that overwhelms the State and District authorities.
History of disasters in India

India is the seventh largest country in the world by land area with the first three large countries being Russia, Canada, and the United States. It is also the second most populous nation in the world with a population of 1.2 billion people. Despite its robust economy and democracy at present, India has experienced some of the worst disasters in the history of the world in the form of famines, earthquakes, cyclones, and tsunamis. Examples of these disasters were the Doji bara famine, Indian famine, Calcutta Cyclone, and the Gujarat Earthquake.

India’s Vulnerability to Disasters

          57% land is vulnerable to earthquakes. Of these, 12% is vulnerable to severe earthquakes. 68% land is vulnerable to drought. 12% land is vulnerable to floods. 8% land is vulnerable to cyclones. Apart from natural disasters, some cities in India are also vulnerable to chemical and industrial disasters and man-made disasters.

Worst Indian Disasters in World History

The worst famine disasters in Indian history were the Doji bara famine, Indian famine, Bengal famine, and Deccan famine. These famines claimed lives of 11, 6, 3, and 2 million people respectively. The Doji bara famine was also known as the “Skull Famine” because at the time, India was covered with large numbers of skulls of the unburied dead. The famine lasted from 1791-1792. It was caused by a major El-niño that lasted from 1789-1795 CE. The El-niño caused a failure of the South Asian monsoon wind for four years resulting in prolonged droughts. In spite of the British having surplus grain supplies, they refused to supply it to those who needed it most. The worst affected areas as indicated by the widespread mortalities were Hyderabad, Deccan, Marwar, Gujarat, and Maratha Kingdom.

The Bengal Famine resulted in 3 million deaths out of an estimated 60.3 million people. It took place in 1943 which was during the World War II. People died of starvation, malaria, and other diseases related to malnutrition, lack of healthcare, unsanitary conditions, and population displacement. The affected areas were Orissa and Bengal. At that time, Bengal’s economy was mainly agrarian. The famine was caused by stagnant crop yield and stable land use which was not proportional to the fast-growing population. Besides, the Bengal Famine may have also been caused by the effects of the ongoing World War.

Among the worst disasters in India were cyclones such as the 1839 India Cyclone, the 1737 Calcutta Cyclone, and the 1999 Odisha Cyclone. The Calcutta Cyclone and India Cyclone each claimed lives of 300,000 Indians. On the other hand, the Odisha Cyclone resulted in deaths of 9,899 people.

Regarding earthquakes, the 2001 Gujarat Earthquake resulted in 20,023 deaths. The number of people who died were the highest ever claimed by an earthquake in India. Another earthquake which preceded the Gujarat one was called the Latur earthquake. It occurred in 1993 and led to the deaths of 10,000 people. Included in the list of the Worst Indian disasters is a 2004 Indian Ocean Tsunami which caused 12,269 deaths.

There are two different types of natural phenomena that cause disasters: the geological ones and those caused by climate. Earthquakes, tidal waves, and volcanic eruptions are among the first ones; all the extreme meteorological phenomena (hurricanes, tornados and storms), droughts and the rising of the sea level due to the melting of polar ice would be examples of the second category. A mixed origin between geological and climatic can be found in some avalanches, which combine excessive melting and landslides. According to the World Bank, disasters caused by climate phenomena have caused two thirds of the global economic and human losses in the last 44 years and have provoked 3.5 million deaths all around the world.

Since earthquakes, tropical storms, and floods are the three main global natural disasters causing the biggest loss, they should be the main focus of research in disaster science and disaster mitigation and prevention. This paper discusses the characteristics of these three global natural disasters from a scientific point of view, and analyses their patterns of distribution, origin and result, as well as the extent of their damage and measures of disaster mitigation and prevention. The paper, at the technical level, introduces the role of earth observation (EO) technologies in disaster mitigation, and real and quasi-real-time monitoring and assessment using advanced optical and microwave EO capacities, while digital earth technologies provide a very important role in rapidly acquiring spatial information of the disaster areas. The paper concludes by discussing the relationship between man and natural disasters, and proposes the viewpoint that man and nature should be able to harmoniously co-exist, and the importance of understanding disasters from an earth system science perspective so as to better meet the challenges of natural disasters.

Concept of risk, hazard and vulnerability

Hazard can be defined as, 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 are conditions that have the potential to harm to a community or environment.

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

Classification of Hazards

Natural

Biological

Technological

Societal

Atmospheric Single element

Excess rainfall

Freezing rain (glaze)

Hail

Heavy snowfalls

High wind speeds

Extreme temperatures

Atmospheric Combined elements/events

Hurricanes

‘Glaze’ storms

Thunderstorms

Blizzards

Tornadoes

Heat/cold stress

2. Hydrologic

Floods – river and coastal

Wave action

Drought

Rapid glacier advance

Geologic

Mass -movement

Land slides

Mudslides

Avalanches

Earthquake

Volcanic eruption

Rapid sediment movement

Biologic

Epidemic in humans

Epidemic in plants

Epidemic in animals

 Locusts

Technologic

Transport accidents

Indus trial explosions and fires

Accidental release of toxic chemicals

 Nuclear accidents

Collapse of public buildings

Secondary hazards

These are hazards that follow as a result of other hazard events.

Hazards secondary to an earthquake may be listed as follows to illustrate the concept.      Primary hazard is the earthquake.

Secondary hazards are

• Building collapse

• Dam failure

• Fire

• Hazardous material spill

• Interruption of power/ water supply/ communication/ transportation/ waste disposal

• Landslide

• Soil liquefaction

• Tsunami (tidal wave)

• Water pollution

Rate of onset Include rapid-onset and slower-acting (slow onset) natural hazards

Multiple hazards

When more than one hazard event impacts the same area, there arises a multiple hazard situation. These different hazard events may occur at the same time or may be spaced out in time. The Return Period

Majority of hazards have return periods on a human time-scale.

Examples are five-year flood, fifty-year flood and a hundred year flood. This reflects a statistical measure of how often a hazard event of a given magnitude and intensity will occur. The frequency is measured in terms of a hazard’s recurrence interval.

Hazard assessment

A hazard is a potentially damaging event and the measure of hazard is it’s probability of occurrence at a certain level of severity within a specified period of time in a given area.

• Hazard identification implies to “what might happen and where?”

• Hazard assessment implies to “How and when?”

"The process of studying the nature "The process of studying the nature of natural /man made hazards of natural /man made hazards determining its essential determining its essential features(degree of severity features(degree of severity ,duration,extent of the impact ,duration, extent of the impact area)and their relationship area)and their relationship"

Assessment Approaches

Quantitative Approach

• Use mathematical functions with numerical values

• Each variable will describe the relationship among parameters that characterize the phenomena

Qualitative Approach

Use qualitative descriptions (such as low, medium or high) instead of numerical values

Assessment Methods

Deterministic Approach.

Determined through associated physical characteristics and analysis of consequences.

Probabilistic Approach

• Estimates the probability of each hazard affecting an area or region, and likelihood of occurrence and can be determined through research studies, simulation studies, etc (eg. Flood/erosion simulation studies, slope stability calculations, landslide hazard zonation).

Informal Ranking

• Uses subjectively defined scales to rank the hazards and associated risks according to an area specific or country specific ranking system.

Usage of hazard information in natural hazard assessment

 Sources

(1) Myths and legends,

(2) Historic records,

(3) Research data.

Hazard assessment techniques and tools

Hazard Zonation mapping

• Hazard maps outline zones that are defined in terms of the probability of occurrence of potentially damaging phenomena within a certain span of time within a specified location or an area.

 

Risk is the probability that negative consequences may arise when hazards interact with vulnerable areas, people, property, environment. Risk is a concept which describes a potential set of consequences that may arise from a given set of circumstances. Risk is a combination of the interaction of hazard, exposure, and vulnerability, which can be represented by the three sides of a triangle.

If any one of these sides increases, the area of the triangle increases, hence the amount of risk also increases. If any one of the sides reduces, the risk reduces. If we can eliminate one side there is no risk.

Parameters of Risk Hazards are the source of risks Hazards create risks by exposing pre-existing vulnerabilities The risk that a community faces is mitigated by its level of preparedness, response and recovery or readiness

Risk is the out come of a hazard. Vulnerability has been defined as the degree to which a system, or part of it, may react adversely during the occurrence of a hazardous event. The disaster occurs when the hazard meets vulnerability.

Vulnerability is a concept which describes factors or constraints of an economic, social, physical or geographic nature, which reduce the ability to prepare for and cope with the impact of hazards

Categories of Vulnerabilities

• Hazard-specific: – a characteristic which makes the element concerned susceptible to the force/s or impact of a hazard. The geo-physical and locational attributes of the element/s concerned are considered in this category. Based on the present-knowledge of the distribution and frequency of hazards, a community or country may be threatened by specific hazards.

• Setting-specific: – this is concerned with the prevailing socio-economic arrangement of the area concerned as to whether it is predominantly rural or urban. There are inherent setting characteristics that may be common to both as well as exclusive to each which contribute to the general susceptibility of the area.

Characteristics of Urban Setting Vulnerabilities

• Concentrations and Crowdedness - the three aspects are crowdedness and disease; crowdedness and buildings; crowdedness and resource base.

• Numbers of Peoples and Activities - the two aspect of this condition are Technologies and the Management System.

• Proximity to Man-made Hazards - the aspects considered are Technological hazards, Economic hazards, and Social Hazards

Other Factors Contributing to Urban Vulnerability

·   Interdependency of Lifelines – Major lifelines of the urban area are dependent on each other to function effectively. This interdependency is a factor that may contribute to the area’s vulnerability.

_·    Social and Organizational Dimension – The existing arrangement of a society regarding relationships of individuals, groups and institutions may create adverse situations that weakens the these elements’ capabilities to face or withstand hazards and contribute instead to the intensifying of the effects

_·    Attitudinal and Motivational Dimension – The prevalent worldview of the society or certain groups within society may contribute to a passive or non-active stance regarding the disasters that beset the area.

Definition of Capacity

_· The resources, means and strengths possessed by persons, communities, societies or countries which enable them to cope with, withstand, prepare for, prevent, mitigate or quickly recover from a disaster.

Dimensions

Awareness – this state of being refers to a population’s level of understanding of the hazards, the warning systems, preparedness measures and the ability to respond or utilize information to counter the effects of the hazards;

Laws and Regulations – these refer to a society’s existing statutes that guide the use of resources for preparation and response to risks brought about by hazards;

Prevention and Mitigation Activities and Projects – these refer to the existing and proposed actions and activities designed to impede the occurrence of a disaster event and/or prevent such an occurrence having harmful effects on the communities and key installations;

Preparedness – this refers to measures which enable governments, communities and individuals to respond rapidly and effectively to disaster situation

Public, Government and NGO Participation and Resources: – this refers both to the relationship the three sectors (i.e., public, government and no) and the use of resources relative to the disasters in the area

Types of Resources

There are two (2) types of resources: national and international. The national resources have two (2) subdivisions: government resources and non-government resources.

 • National Resources are “assets” and/or “wealth” which a country possesses

 • International Resources are external “means” which a country may tap or access for disaster management purposes.

Evaluation of Resources by Assessing

• Capability

• Availability

• Durability

• Operational Integrity

Coping Mechanisms

• Actions resorted to by individuals or groups in face of adverse effects of a disaster in order to survive/withstand and move towards normalization.

Parameters of Risk

·         Hazards are the source of risks

_·          Hazards create risks by exposing pre-existing vulnerabilities

_·          The risk that a community faces is mitigated by its level of preparedness, response and recovery or readiness

Dameges caused by disasters

Damages

Tangible losses -Measurable effects in Monetary Terms.

Intangible Losses -Effects those can not be converted to Monetary Terms.

Preparedness

Short term risk reduction measures taken in anticipation of a disaster to ensure that appropriate and effective actions are taken in the aftermath.

Mitigation

1.   Strong buildings & structures,

2.   strict building codes

3.   compliance,

4.   landuse planning,

5.   capacity building,

6.   awareness creation etc.

•Long term risk reduction measures taken prior to the impact of a disaster to minimize its effects (sometimes referred to as structural and non-structural measures).