Disaster Meaning and Classification

Meaning and Classification of Disasters

• This unit covers disaster terminology, the differences between natural and man-made disasters, and an overview of disaster classification
• Disasters have been part of human history, causing casualties, economic and social losses, and environmental damage
• 'Disaster' comes from the French word 'Desastre', originally referring to unfavorable stars

Disaster Defined

• Today, a disaster refers to any adverse event, natural or man-made, causing significant misery that local resources cannot manage
• The Disaster Management Act, 2005 defines "disaster" as a catastrophe from natural or man-made causes, resulting in substantial loss of life, suffering, property damage, environmental degradation, exceeding the affected community's coping capacity
• The International Federation of Red Cross and Red Crescent Societies defines "disaster" as a sudden event that disrupts a community, causing human, material, economic, and environmental losses beyond the community's ability to cope
• Disasters cause disruptions to society, leading to loss of life, property, economic and social structure impacts
• Disasters lead to shelter shortages, psychological trauma, livelihood loss, infrastructure disruption, law and order issues, and migration

Negative and Positive Impacts of Disasters

• Disasters can lead to development and innovation
• Disasters can foster sharing, awareness, self-sufficiency, transformation, education, and resilience

Types of Disasters

• Disasters are classified into natural and man-made categories with various sub-categories (High Powered Committee Report, 2001)

Water and Climate Related Disasters

• Floods
• Cyclones
• Tornadoes and Hurricanes
• Hailstorms
• Cloud Bursts
• Heat and Cold Waves
• Snow Avalanches
• Droughts
• Sea Erosion
• Thunder and Lightning
• Tsunamis

Geologically Related Disasters

• Landslides and Mudflows
• Earthquakes
• Dam Failures/Dam Bursts

Chemical, Industrial, and Nuclear Related Disasters

• Chemical and Industrial Disasters
• Nuclear Disasters

Accident Related Disasters

• Forest Fires
• Urban Fires
• Mine Fires and Flooding
• Oil Spills
• Major Building Collapse
• Serial Bomb Blasts
• Festival Related Disasters
• Electrical Disasters and Fires
• Boat Capsizing
• Village Fires

Biological Disasters

• Biological Hazards
• Epidemics
• Pest Attacks
• Cattle Epidemics
• Food Poisoning

Natural Disasters Explained

• Natural disasters are physical events caused by rapid or slow geophysical hydrological, climatological, and biological processes
• Earthquakes result from structural deformation within the earth, causing ground vibration and potential collapse
• Earthquakes occur at fault lines, triggering landslides, tidal waves, and tsunamis, that are measured using the Richter scale

Volcanic Eruptions

• Volcanic eruptions involve lava and gas discharge, and creating pyroclastic flows up to 1,200°C
• Volcanoes erupt in explosive or effusive modes depending on magma composition and gas content

Landslides

• Landslides are soil or rock movements due to gravity, influenced by rain, erosion, or tremors
• Landslides are associated with cyclones, storms, and floods

Tsunamis

• Tsunamis, also known as seismic sea waves are caused by earthquakes, landslides, or volcanic activity, displacing the sea floor
• Tsunamis are large waves with long wavelengths
• Tsunamis can travel thousands of miles, and be triggered by earthquakes, volcanic eruptions, mass movements, meteorite impacts, etc.

Avalanches

• Avalanches are masses of snow or ice sliding down mountainsides
• Avalanches are triggered by earthquakes and volcanic eruptions, being classified as "dry snow" or "wet snow" types, with "direct action" or "delayed action" sub-divisions

Floods

• Floods are water overflows commonly affecting parts of a country
• The Ministry of Home Affairs defines "floods" as temporary inundations from reservoir increases, river flooding, heavy rains, cyclones, storm surges, tsunamis, melting snow, or dam bursts
• Flash floods occur rapidly within six hours of heavy rainfall, often from cloud bursts, and requiring quick warnings

Extreme Temperatures

• Heat waves are prolonged periods of excessively hot weather that strain the human body
• Cold waves are prolonged periods of extremely cold weather that damage agriculture, infrastructure, and immobilize regions
• Winter storms cause flooding, storm surge, and closed highways

Droughts

• Drought is rainfall deficiency over a long period, which depends on moisture deficiency, dry spells and irrigation availability
• Drought tightens its devastation over time, leading to water shortages, affecting agriculture, and causing food insecurity, famine, malnutrition, epidemics, and displacement

Wildfires

• Wildfires include forest, grassland, and brush fires, spreading quickly under high temperatures and winds
• Wildfires occur in coniferous and evergreen forests

Tropical Cyclones & Storm Surges

• Cyclones are characterized by inward spiraling winds around low pressure zones, with counterclockwise rotation in the Northern Hemisphere and clockwise in the Southern Hemisphere
• Tropical cyclones are storms with low-pressure centers producing strong winds and flooding rain
• Cyclones feed on moist air, leading to water vapor condensation
• Storm surges are coastal floods associated with low pressure weather systems, impacted by water body depth and tides, causing many casualties

Epidemics

• Epidemics are unusual increases in infectious diseases
• Epidemics can result from disasters like storms, floods, earthquakes, droughts, etc.
• Diseases include hepatitis, typhoid, diphtheria, malaria, cholera, influenza, enteritis, skin diseases, and food poisoning

Man-Made Disasters

• Man-made disasters caused by human activities in human environment, can cause environmental degradation, pollution, and accidents

Complex Emergencies/Conflicts

• Humanitarian crises with authority breakdowns needing international response include war leading to medical issues, refugee problems, and violence

Famines

• Food-security emergencies arise from drought or conflict and poverty, HIV/AIDS, mismanagement
• Food shortages reduce disease resistance while security problems cause migration

Displaced Populations

• Displaced populations leave homes due to disasters, conflict, and require relief

Transport Accidents

• Transport accidents are technological accidents involving air, boat, rail, and road

Industrial Accidents

• Industrial accidents include chemical, nuclear, and mine explosions, that cause pollution

Other Classifications of Disaster

• Disasters highlight human neglect and disrupt aspects that create uncertainty
• Disasters are the cause of loss of life, damage property, create irreversible changes, divert resources while also impacting relief

Compound & Complex Disasters

• Compound disasters cause one hazard to lead to another
• Complex disasters cause political authority to collapse or create political situations such as bias when distributing relief

Glossary of Disasters

• Disaster: A sudden, calamitous event disrupting a community or society
• Natural Disaster: Caused by natural phenomena
• Man-made Disasters: Caused by humans
• Compound Disaster: One hazard leading to other contingencies
• Complex Disasters: Disasters leading to political authority collapse or political issues