🌋Natural and Human Disasters Unit 1 – Natural and Human Disasters: An Introduction

Key Concepts and Definitions

• Natural disasters sudden events caused by natural processes of the Earth (earthquakes, hurricanes, floods) resulting in significant damage and loss of life
• Human-made disasters catastrophic events caused by human activities or decisions (industrial accidents, oil spills, nuclear meltdowns) leading to widespread harm
• Hazard potential source of harm or adverse effects on people, property, or the environment
  • Can be natural (volcanic eruptions) or human-made (chemical spills)
• Risk probability of harmful consequences resulting from interactions between hazards, vulnerable conditions, and insufficient capacity to reduce potential negative consequences
• Vulnerability susceptibility of a community or system to the damaging effects of a hazard
  • Influenced by physical, social, economic, and environmental factors
• Resilience capacity of a system, community, or society to resist, absorb, accommodate, adapt to, transform, and recover from disasters in a timely and efficient manner
• Mitigation actions taken to reduce the severity or impact of a disaster (building codes, land-use planning, public awareness)

Types of Natural Disasters

• Geological disasters related to Earth's surface and subsurface processes (earthquakes, volcanic eruptions, landslides, sinkholes)
• Hydrological disasters involving water-related phenomena (floods, tsunamis, avalanches)
• Meteorological disasters associated with weather and atmospheric conditions (hurricanes, tornadoes, blizzards, droughts)
• Climatological disasters linked to long-term climate patterns (heat waves, wildfires, desertification)
• Biological disasters caused by the exposure to living organisms and their toxic substances or vector-borne diseases (epidemics, insect infestations)
  • Can be influenced by human activities (deforestation, urbanization)
• Space disasters originating from outer space (asteroid impacts, solar flares)

Types of Human-Made Disasters

• Technological disasters caused by the failure of technological systems (industrial accidents, transportation accidents, structural collapses)
• Environmental disasters resulting from human activities that damage the environment (oil spills, chemical leaks, nuclear meltdowns)
  • Often have long-lasting effects on ecosystems and human health
• Societal disasters arising from social, political, or economic factors (terrorism, civil unrest, economic crises, wars)
• Hybrid disasters complex emergencies that combine natural and human-made elements (famine, displacement, refugee crises)
• Cybersecurity disasters caused by the failure or breach of computer systems and networks (cyberattacks, data breaches, infrastructure disruptions)
• Urban disasters occurring in densely populated urban areas (urban fires, building collapses, infrastructure failures)
  • Magnified by high population density and interdependent systems

Causes and Triggers

• Natural factors geological processes, weather patterns, and biological agents that can trigger disasters
  • Plate tectonics, volcanic activity, and seismic shifts cause earthquakes and tsunamis
  • Atmospheric circulation patterns and ocean currents influence hurricanes, tornadoes, and floods
• Human activities decisions, actions, and inactions that contribute to or exacerbate disasters
  • Deforestation, urbanization, and land-use changes increase vulnerability to landslides and floods
  • Greenhouse gas emissions and climate change amplify the frequency and intensity of extreme weather events
• Technological failures malfunctions, design flaws, or operator errors in technological systems leading to accidents and disasters (Chernobyl nuclear disaster, Deepwater Horizon oil spill)
• Societal factors social, political, and economic conditions that create vulnerabilities and contribute to disasters
  • Poverty, inequality, and marginalization increase exposure and susceptibility to hazards
  • Conflict, instability, and weak governance hinder disaster preparedness and response
• Cascading effects initial disaster triggering secondary hazards or failures, amplifying the overall impact (earthquake causing landslides, dam failures, and fires)

Impact and Consequences

• Physical damage destruction of infrastructure, buildings, and natural environments
  • Collapsed buildings, damaged roads and bridges, and disrupted utilities
  • Erosion, deforestation, and habitat destruction
• Human casualties deaths, injuries, and displacement of affected populations
  • Immediate fatalities and long-term health effects (trauma, disease, malnutrition)
  • Forced migration and refugee crises
• Economic losses direct and indirect costs of disasters on local, regional, and global economies
  • Property damage, business interruptions, and reduced productivity
  • Strain on public finances and diversion of resources towards recovery efforts
• Social disruption breakdown of social networks, community cohesion, and cultural heritage
  • Displacement, separation of families, and loss of livelihoods
  • Erosion of trust, increased social tensions, and mental health impacts
• Environmental degradation pollution, contamination, and loss of biodiversity resulting from disasters
  • Oil spills, chemical leaks, and nuclear fallout damaging ecosystems
  • Deforestation, soil erosion, and habitat fragmentation
• Long-term effects persistent challenges and obstacles to recovery and development
  • Rebuilding infrastructure, restoring livelihoods, and addressing psychological trauma
  • Increased vulnerability to future disasters and setbacks in sustainable development goals

Disaster Management Cycle

• Mitigation pre-disaster actions to reduce the likelihood or impact of future disasters
  • Implementing building codes, land-use planning, and public awareness campaigns
  • Investing in early warning systems and strengthening critical infrastructure
• Preparedness planning and capacity-building to effectively respond to and cope with disasters
  • Developing emergency response plans, conducting drills and exercises
  • Stockpiling supplies, training personnel, and establishing coordination mechanisms
• Response immediate actions taken during and immediately after a disaster to save lives and minimize damage
  • Search and rescue operations, emergency medical care, and evacuation
  • Provision of shelter, food, water, and basic necessities to affected populations
• Recovery post-disaster efforts to restore and rebuild affected communities
  • Repairing damaged infrastructure, restoring essential services, and rebuilding homes
  • Providing psychosocial support, livelihood assistance, and long-term recovery planning
• Prevention proactive measures to avoid the occurrence of disasters altogether
  • Addressing root causes, such as poverty, inequality, and environmental degradation
  • Promoting sustainable development, conflict resolution, and climate change mitigation

Risk Assessment and Mitigation Strategies

• Hazard identification process of recognizing and characterizing potential sources of harm
  • Conducting historical analysis, scientific modeling, and community-based assessments
  • Mapping hazard zones and understanding their frequency, intensity, and spatial distribution
• Vulnerability assessment evaluating the susceptibility of people, assets, and systems to the impacts of hazards
  • Analyzing physical, social, economic, and environmental factors that influence vulnerability
  • Identifying vulnerable populations, critical infrastructure, and key resources
• Risk analysis systematic process of understanding the nature, magnitude, and likelihood of potential consequences
  • Quantifying risks using probabilistic models, scenario analysis, and stakeholder input
  • Prioritizing risks based on their potential impact, likelihood, and societal concerns
• Mitigation strategies actions taken to reduce or eliminate long-term risks from hazards
  • Structural measures (building codes, retrofitting, protective infrastructure)
  • Non-structural measures (land-use planning, public awareness, insurance)
  • Nature-based solutions (ecosystem restoration, green infrastructure)
• Resilience-building enhancing the capacity of communities and systems to withstand, adapt to, and recover from disasters
  • Strengthening social networks, diversifying livelihoods, and promoting adaptive governance
  • Investing in education, health, and infrastructure to reduce underlying vulnerabilities

Case Studies and Historical Examples

• Great Hanshin Earthquake (1995) magnitude 7.3 earthquake that struck Kobe, Japan, causing widespread destruction and over 6,000 fatalities
  • Highlighted the vulnerability of urban areas and the need for improved building codes and emergency response
• Hurricane Katrina (2005) Category 5 hurricane that devastated the U.S. Gulf Coast, particularly New Orleans, resulting in over 1,800 deaths and massive economic losses
  • Exposed social inequalities, inadequate flood protection, and failures in disaster management
• Chernobyl Nuclear Disaster (1986) catastrophic nuclear accident in Ukraine, former Soviet Union, releasing radioactive material across Europe
  • Demonstrated the risks of nuclear power and the long-term environmental and health consequences
• Bhopal Gas Tragedy (1984) industrial disaster in Bhopal, India, where a gas leak from a pesticide plant killed thousands and affected over 500,000 people
  • Raised concerns about industrial safety, corporate responsibility, and the vulnerability of marginalized communities
• Tohoku Earthquake and Tsunami (2011) magnitude 9.0 earthquake off the coast of Japan, triggering a devastating tsunami and the Fukushima nuclear disaster
  • Highlighted the cascading effects of disasters and the challenges of multi-hazard risk management
• Exxon Valdez Oil Spill (1989) oil tanker accident in Alaska, USA, releasing 37,000 tons of crude oil into pristine marine environments
  • Demonstrated the environmental and economic consequences of oil spills and the difficulties of cleanup and restoration
• Haiti Earthquake (2010) magnitude 7.0 earthquake that struck Haiti, causing widespread destruction, over 200,000 deaths, and displacing millions
  • Exposed the vulnerability of developing countries and the challenges of post-disaster recovery in contexts of poverty and weak governance