Understanding Disasters: Types, Concepts & Perspectives

• A disaster is a serious disruption that overwhelms a community's ability to cope with human, material, economic, or environmental losses.

Types of Disasters

• Natural Disasters – Caused by natural events like earthquakes, floods, and tsunamis.
• Human-made Disasters – Result from human activities, such as hazardous material spills and nuclear accidents.

Key Concepts

• Hazard - A potential danger or threat.

• Exposure - The people or structures that may be affected by hazards.

• Vulnerability – The inability to cope with hazards due to factors like poverty, poor planning, or weak structures.

• Capacity - The ability to prepare for, respond to, and recover from disasters.

• Risk = Hazard × Vulnerability

• An event becomes a disaster when it causes significant damage and overwhelms a community's capacity to respond.

Perspectives on Disasters

• Physical - Destruction of buildings, roads, and infrastructure.
• Psychological – Trauma, stress, and mental health issues.
• Socio-cultural – Changes in community roles, relationships, and traditions.
• Economic - Loss of jobs, income, and businesses.
• Political - Government response, laws, and policies.
• Biological - Disease outbreaks, pandemics.
• A disaster happens when a hazard affects a vulnerable community that lacks the capacity to cope.

Exposure & Vulnerability

• Elements Exposed to Hazards: People and Buildings & Infrastructure
• Economic Sectors – Businesses, jobs, and industries.
• Environment – Forests, rivers, and ecosystems.

Types of Vulnerability

• Physical - Weak buildings and lack of evacuation routes.
• Social - Lack of education, healthcare, and awareness.
• Economic - Poverty, low income, and job instability.
• Environmental – Deforestation, pollution, and climate change.
• Sectors are more vulnerable due to high population density, poor urban planning, lack of disaster preparedness and limited access to resources.

Hazards, Exposure, And Risk

• Risk Triangle Components: Hazard, Exposure and Vulnerability
• Reducing Risk involves strengthening buildings and infrastructure, implementing early warning systems, and raising community awareness and preparedness.

Classification of Hazards

• Types of Hazards: Geologic, Hydrometeorological, Atmospheric, Biological, and Human-Induced
• Primary effects are immediate, such as ground shaking and flooding.
• Secondary effects are indirect, such as landslides after an earthquake.
• Tertiary effects are long-term, such as food shortages and loss of livelihood.

Earthquake Hazards

• Potential Hazards: Ground Shaking, Ground Rupture, Liquefaction, Tsunami, Landslides, Fires
• Natural Signs of an Impending Tsunami: Strong earthquake near the coast, unusual rapid sea level drop, and loud ocean roar.

Safety Measures For an Earthquake

• Before: Conduct earthquake drills and secure heavy objects. Prepare an emergency kit.
• During (DROP, COVER, and HOLD ON!): Stay indoors and take cover under sturdy furniture. Avoid windows, glass, and heavy objects.
• After: Expect aftershocks and move to an open area. Check for injuries and structural damage before returning home.

Volcanic Hazards

• Lava Flows are slow-moving molten rock. Pyroclastic Flows are a hot gas and lash moving at high speeds and Ash Fall is when fine particles can cause breathing problems. Lahars are volcanic mudflows due to heavy rain and ash. Volcanic Earthquakes happen due to seismic activity by magma movement.
• Signs of an Impending Volcanic Eruption: Increase in volcanic earthquakes and have Strong steam or gas emissions.

Safety Measures Before, During, And After A Volcanic Eruption

• Before: Prepare emergency kits, know evacuation routes, and protect water sources from ashfall.
• During: Stay indoors, wear a mask, and avoid low-lying areas. Follow authorities' instructions and stay in evacuation centers.
• After: Wait for official clearance before returning home. Avoid contact with volcanic ash and contaminated water.

Other Related Geological Hazards

• Landslides Causes: Heavy rain, earthquakes, and deforestation. Warning Signs: Cracks in the ground, leaning trees, and sudden water seepage. Safety Measures: Move away from steep slopes and stay alert for warnings.
• Sinkholes Causes: Underground water erosion, mining, and excessive groundwater extraction. Warning Signs: Depressions in the ground, tilting fences, or buildings. Safety Measures: Avoid unstable land and report warning signs to authorities.

Key Takeaways

• Disasters happen when hazards affect vulnerable communities with a low capacity to respond.
• Understanding risk factors helps reduce disaster impacts.
• Preparedness and mitigation save lives
• Government and community action plans are crucial for disaster management.

Explore disasters, from natural events to human-made incidents, and key concepts like hazard, exposure, and vulnerability. Learn how these elements combine to create risk and overwhelm communities. Understand the physical, psychological, and socio-economic effects of disasters.