Disaster Management Notes

Definitions of Disaster and Hazard

  • Disaster: A sudden, catastrophic event causing significant disruption, destruction, loss of life, property, and resources, overwhelming community coping ability.

    • Types:

    • Natural (e.g., earthquakes, floods)

    • Man-made (e.g., industrial accidents)

  • Hazard: A potential threat with the ability to cause harm to people, property, or the environment.

    • Types:

    • Natural hazards (e.g., earthquakes)

    • Human-made hazards (e.g., chemical spills)

    • Biological hazards (e.g., pandemics)

    • Key Difference: Hazard is the potential risk; disaster occurs when the hazard results in significant damage.

Vulnerability

  • Definition: The degree of susceptibility or inability to withstand and recover from hazards.

  • Influencing Factors: Poverty, infrastructure, education, health, and governance.

Types of Vulnerability

  1. Physical Vulnerability

    • Susceptibility of buildings and infrastructure to hazards.

    • Example: Poorly constructed houses in earthquake-prone areas.

  2. Social Vulnerability

    • Impact based on social factors (e.g., poverty, age).

    • Example: Elderly individuals may struggle to evacuate during floods.

  3. Economic Vulnerability

    • Financial capacity to prepare for and recover from disasters.

    • Example: A low-income family unable to afford insurance.

  4. Environmental Vulnerability

    • Degradation of ecosystems increasing susceptibility to hazards.

    • Example: Deforestation leading to landslides.

Natural & Man-made Disasters

  • Natural Disasters: Caused by natural forces.

    • Types:

    • Geological (Earthquakes, tsunamis)

    • Hydrometeorological (Floods, droughts)

    • Biological (Pandemics)

    • Example: 2004 Indian Ocean tsunami.

  • Man-made Disasters: Result from human activities.

    • Types:

    • Industrial (Chemical spills)

    • Environmental (Deforestation)

    • Example: Bhopal Gas Tragedy.

  • Key Differences:

    • Cause: Natural vs human actions.

    • Prevention: Natural disasters cannot be prevented; man-made can often be.

Comprehensive List of Disasters

1. Natural Disasters:

  • Geological: Earthquakes, tsunamis, volcanic eruptions.

  • Hydrometeorological: Floods, hurricanes, tornadoes.

  • Biological: Pandemics, pest infestations.

2. Man-Made Disasters:

  • Industrial: Chemical spills, nuclear accidents.

  • Environmental: Oil spills, deforestation.

  • Transportation: Airplane crashes, train derailments.

  • Conflict-related: Wars, terrorism.

3. Hybrid Disasters:

  • Combine natural and human causes (e.g., climate change).

Key Disaster-Related Terms

  1. Risk: Likelihood of a disaster causing harm.

    • Formula: Risk = Hazard × Vulnerability × Exposure.

    • Example: High risk of flooding in poorly drained coastal cities.

  2. Capacity: Ability to withstand and recover.

    • Categories: Physical, social, economic.

  3. Impact: Consequences of a disaster.

    • Types: Human, economic, and environmental impacts.

  4. Prevention: Actions to avoid disasters.

    • Example: Earthquake-resistant buildings.

  5. Mitigation: Measures to reduce impact.

    • Example: Early warning systems for tsunamis.

Earthquakes: Causes & Effects

Causes:

  1. Tectonic Plate Movements: Earth's crust movement.

  2. Volcanic Activity: Magma movement causing shaking.

  3. Human-Induced: Mining, reservoir-induced seismicity.

Effects:

  1. Primary Effects: Ground shaking, surface rupture.

  2. Secondary Effects: Tsunamis, fires, soil liquefaction.

  3. Social and Economic: Casualties, homelessness, economic losses.

Floods & Droughts

Floods:

  • Definition: Overflow of water onto dry land.

  • Causes: Heavy rainfall, river overflow, dam failures.

  • Effects: Loss of life, displacement, waterborne diseases.

Droughts:

  • Definition: Prolonged period of low rainfall.

  • Causes: Lack of rain, climate change, deforestation.

  • Effects: Water scarcity, crop failure, economic crisis.

Tsunamis

Definition: Series of large ocean waves due to water displacement.

  • Causes: Underwater earthquakes, volcanic eruptions, landslides.

  • Characteristics: High speed, multiple waves, destructive upon landfall.

Flood Management in India

  • Causes: Heavy monsoon rains, river overflow.

  • Strategies:

    • Structural: Dams, drainage improvements.

    • Non-Structural: Early warning systems, disaster preparedness.

Hazard Profile of India

  • Natural Hazards: Earthquakes (58% of land), floods (12%), droughts (68%).

  • Disaster management: NDMA, SDRF.

Global Disaster Scenario

  • Types:

    • Geological: Earthquakes, volcanic eruptions.

    • Hydro-Meteorological: Floods, droughts, heatwaves.

    • Biological: Pandemics, epidemics.

    • Man-Made: Industrial disasters, conflicts.

  • Trends: Increasing frequency, climate change impact.

Climate Change

  • Definition: Long-term shifts in weather patterns.

  • Causes: Greenhouse gas emissions, deforestation, industrial activities.

  • Effects on Disasters: Increased frequency/intensity of extreme weather events, rising sea levels, disruptions to ecosystems.

Conclusion

  • Disasters significantly impact human life and the environment. Effective management strategies, preparedness, and climate mitigation are crucial to reduce risks and enhance resilience.