A disaster is a serious disruption of the functioning of a community or a society involving widespread human, material, economic, or environmental losses and impacts, which exceed 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 hazard/s and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in 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 Desastre and that from Old Italian disastro, which in turn comes from the 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 sight of planets.
Researchers have been studying disasters for more than a century and for more than forty years of 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 from developing into a disaster. All disasters are hence the result of human failure to introduce appropriate disaster 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.
In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazard/s and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in 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 Desastre and that from Old Italian disastro, which in turn comes from the 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 sight of planets.
Researchers have been studying disasters for more than a century and for more than forty years of 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 from developing into a disaster. All disasters are hence the result of human failure to introduce appropriate disaster 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.
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A tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud.
They are often referred to as twisters or cyclones, although the word cyclone is used in meteorology, in a wider sense, to name any closed low-pressure circulation.
Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust. Most tornadoes have wind speeds of less than 110 miles per hour (180 km/h), are about 250 feet (80 m) across, and travel a few miles (several kilometers) before dissipating.
The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (480 km/h), stretch more than two miles (3 km) across, and stay on the ground for dozens of miles (more than 100 km).
They are often referred to as twisters or cyclones, although the word cyclone is used in meteorology, in a wider sense, to name any closed low-pressure circulation.
Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust. Most tornadoes have wind speeds of less than 110 miles per hour (180 km/h), are about 250 feet (80 m) across, and travel a few miles (several kilometers) before dissipating.
The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (480 km/h), stretch more than two miles (3 km) across, and stay on the ground for dozens of miles (more than 100 km).
Various types of tornadoes include the landspout, multiple vortex tornado, and waterspout. Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-super cellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes. These spiraling columns of air frequently develop in tropical areas close to the equator and are less common at high latitudes. Other tornado-like phenomena that exist in nature include the gust ado, dust devil, fire whirls, and steam devil; downbursts are frequently confused with tornadoes, though their action is dissimilar.
Tornadoes have been observed on every continent except Antarctica. However, the vast majority of tornadoes occur in the Tornado Alley region of the United States, although they can occur nearly anywhere in North America. They also occasionally occur in south-central and eastern Asia, northern and east-central South America, Southern Africa, northwestern and southeast Europe, western and southeastern Australia, and New Zealand. Tornadoes can be detected before or as they occur through the use of Pulse-Doppler radar by recognizing patterns in velocity and reflectivity data, such as hook echoes or debris balls, as well as through the efforts of storm spotters.
There are several scales for rating the strength of tornadoes. The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale. An F0 or EF0 tornado, the weakest category, damages trees, but not substantial structures. An F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers. The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. Doppler radar data, photogrammetry, and ground swirl patterns (cycloidal marks) may also be analyzed to determine the intensity and assign a
Tornadoes have been observed on every continent except Antarctica. However, the vast majority of tornadoes occur in the Tornado Alley region of the United States, although they can occur nearly anywhere in North America. They also occasionally occur in south-central and eastern Asia, northern and east-central South America, Southern Africa, northwestern and southeast Europe, western and southeastern Australia, and New Zealand. Tornadoes can be detected before or as they occur through the use of Pulse-Doppler radar by recognizing patterns in velocity and reflectivity data, such as hook echoes or debris balls, as well as through the efforts of storm spotters.
There are several scales for rating the strength of tornadoes. The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale. An F0 or EF0 tornado, the weakest category, damages trees, but not substantial structures. An F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers. The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. Doppler radar data, photogrammetry, and ground swirl patterns (cycloidal marks) may also be analyzed to determine the intensity and assign a
A natural hazard 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 which make the disaster-prone areas more vulnerable, tardy communication, and poor or no budgetary allocation for disaster prevention, developing countries suffer more or less chronically from natural disasters. Asia tops the list of casualties caused by natural hazards.
Airplane crashes and terrorist attacks are examples of man-made disasters: they cause pollution, kill people, and damage property. This example is the September 11 attacks in 2001 at the World Trade Center in New York.
Human-instigated disasters Main article: Man-made disasters
Human-instigated disasters are the consequence of technological hazards. Examples include stampedes, fires, transport accidents, industrial accidents, oil spills, and nuclear explosions/radiation. War and deliberate attacks may also be put in this category. As with natural hazards, man-made hazards are events that have not happened—for instance, terrorism. Man-made disasters are examples of specific cases where man-made hazards have become a reality in an event.
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 which make the disaster-prone areas more vulnerable, tardy communication, and poor or no budgetary allocation for disaster prevention, developing countries suffer more or less chronically from natural disasters. Asia tops the list of casualties caused by natural hazards.
Airplane crashes and terrorist attacks are examples of man-made disasters: they cause pollution, kill people, and damage property. This example is the September 11 attacks in 2001 at the World Trade Center in New York.
Human-instigated disasters Main article: Man-made disasters
Human-instigated disasters are the consequence of technological hazards. Examples include stampedes, fires, transport accidents, industrial accidents, oil spills, and nuclear explosions/radiation. War and deliberate attacks may also be put in this category. As with natural hazards, man-made hazards are events that have not happened—for instance, terrorism. Man-made disasters are examples of specific cases where man-made hazards have become a reality in an event.
A disaster recovery plan (D.R.P) is a documented process or set of procedures to recover and protect a business's IT infrastructure in the event of a disaster. Such a plan, ordinarily documented in written form, specifies procedures an organization is to follow in the event of a disaster. It is "a comprehensive statement of consistent actions to be taken before, during, and after a disaster."
The disaster could be natural, environmental or man-made. Man-made disasters could be intentional (for example, an act of a terrorist) or unintentional (that is, accidental, such as the breakage of a man-made dam).
Given organizations' increasing dependency on information technology to run their operations, a disaster recovery plan, sometimes erroneously called a Continuity of Operations Plan (COOP), is increasingly associated with the recovery of information technology data, assets, and facilities.
The disaster could be natural, environmental or man-made. Man-made disasters could be intentional (for example, an act of a terrorist) or unintentional (that is, accidental, such as the breakage of a man-made dam).
Given organizations' increasing dependency on information technology to run their operations, a disaster recovery plan, sometimes erroneously called a Continuity of Operations Plan (COOP), is increasingly associated with the recovery of information technology data, assets, and facilities.
Objectives Organizations cannot always avoid disasters, but with careful planning, the effects of a disaster can be minimized. The objective of a disaster recovery plan is to minimize downtime and data loss. The primary objective is to protect the organization in the event that all or part of its operations and/or computer services are rendered unusable. The plan minimizes the disruption of operations and ensures that some level of organizational stability and an orderly recovery after a disaster will prevail. Minimizing downtime and data loss is measured in terms of two concepts: the recovery time objective (R.T.O) and the recovery point objective (R.P.O).
The recovery time objective is the time within which a business process must be restored after a major incident (MI) has occurred, in order to avoid unacceptable consequences associated with a break in business continuity. The recovery point objective (RPO) is the age of files that must be recovered from backup storage for normal operations to resume if a computer, system, or network goes down as a result of a MI. The R.P.O is expressed backward in time (that is, into the past) starting from the instant at which the MI occurs, and can be specified in seconds, minutes, hours, or days. The recovery point objective (R.P.O) is thus the maximum acceptable amount of data loss measured in time. It is the age of the files or data in backup storage required to resume normal operations after the major incident. (MI)
There is no one right type of disaster recovery plan, nor is there a one-size-fits-all disaster recovery plan. However, there are three basic strategies that feature in all disaster recovery plans: (1) preventive measures, (2) detective measures, and (3) corrective measures. Preventive measures will try to prevent a disaster from occurring. These measures seek to identify and reduce risks. They are designed to mitigate or prevent an event from happening. These measures may include keeping data backed up and off-site, using surge protectors, installing generators, and conducting routine inspections. Detective measures are taken to discover the presence of any unwanted events within the IT infrastructure. Their aim is to uncover new potential threats. They may detect or uncover unwanted events. These measures include installing fire alarms, using up-to-date antivirus software, holding employee training sessions, and installing server and network monitoring software. Corrective measures are aimed to restore a system after a disaster or otherwise unwanted event takes place. These measures focus on fixing or restoring the systems after a disaster. Corrective measures may include keeping critical documents in the Disaster Recovery Plan or securing proper insurance policies, after a "lessons learned" brainstorming session.
A disaster recovery plan must answer at least three basic questions: (1) what its objective and purpose is, (2) who will be the people or teams who will be responsible in case any disruptions happen, and (3) what these people will do (the procedures to be followed) when the disaster strikes.
The recovery time objective is the time within which a business process must be restored after a major incident (MI) has occurred, in order to avoid unacceptable consequences associated with a break in business continuity. The recovery point objective (RPO) is the age of files that must be recovered from backup storage for normal operations to resume if a computer, system, or network goes down as a result of a MI. The R.P.O is expressed backward in time (that is, into the past) starting from the instant at which the MI occurs, and can be specified in seconds, minutes, hours, or days. The recovery point objective (R.P.O) is thus the maximum acceptable amount of data loss measured in time. It is the age of the files or data in backup storage required to resume normal operations after the major incident. (MI)
There is no one right type of disaster recovery plan, nor is there a one-size-fits-all disaster recovery plan. However, there are three basic strategies that feature in all disaster recovery plans: (1) preventive measures, (2) detective measures, and (3) corrective measures. Preventive measures will try to prevent a disaster from occurring. These measures seek to identify and reduce risks. They are designed to mitigate or prevent an event from happening. These measures may include keeping data backed up and off-site, using surge protectors, installing generators, and conducting routine inspections. Detective measures are taken to discover the presence of any unwanted events within the IT infrastructure. Their aim is to uncover new potential threats. They may detect or uncover unwanted events. These measures include installing fire alarms, using up-to-date antivirus software, holding employee training sessions, and installing server and network monitoring software. Corrective measures are aimed to restore a system after a disaster or otherwise unwanted event takes place. These measures focus on fixing or restoring the systems after a disaster. Corrective measures may include keeping critical documents in the Disaster Recovery Plan or securing proper insurance policies, after a "lessons learned" brainstorming session.
A disaster recovery plan must answer at least three basic questions: (1) what its objective and purpose is, (2) who will be the people or teams who will be responsible in case any disruptions happen, and (3) what these people will do (the procedures to be followed) when the disaster strikes.