Disaster Management Concepts

Cheatsheet Content

1. Disaster Definition: A serious disruption of the functioning of a community or a society at any scale due to hazardous events interacting with conditions of exposure, vulnerability and capacity, leading to one or more of the following: human, material, economic and environmental losses and impacts. Key Characteristics: Exceeds the affected community's or society’s ability to cope using its own resources. Can be sudden-onset (e.g., earthquake) or slow-onset (e.g., drought). Often results from a combination of natural and human-induced factors. 2. Hazard Definition: A dangerous phenomenon, substance, human activity or condition 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. Types of Hazards: Natural Hazards: Geophysical (earthquakes, volcanoes), Hydrological (floods, tsunamis), Meteorological (storms, heatwaves), Climatological (droughts, wildfires), Biological (epidemics, pandemics). Technological/Human-induced Hazards: Industrial accidents, pollution, infrastructure failure, terrorism. Socio-natural Hazards: Landslides and floods exacerbated by deforestation. Severity: The potential magnitude of the hazard's impact. Measured by intensity (e.g., Richter scale for earthquakes, Saffir-Simpson for hurricanes) or force. Frequency: How often a hazard event occurs over a given period. Can be rare, occasional, or frequent. Often expressed as a return period (e.g., "100-year flood"). 3. Vulnerability Definition: The characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard. Factors Contributing to Vulnerability: Physical: Poorly constructed buildings, lack of infrastructure. Social: Age, gender, disability, social exclusion, lack of education, weak social networks. Economic: Poverty, unemployment, reliance on a single economic sector, lack of insurance. Environmental: Degradation of ecosystems (e.g., deforestation, coastal erosion). Institutional: Weak governance, lack of early warning systems, poor emergency services. Vulnerability is dynamic and changes over time and space. 4. Risks Definition: The potential for losses (deaths, injuries, property, livelihoods, economic activity disrupted or environment damaged) to a system, society or a community due to a hazard event. Risk is often expressed as the product of hazard, exposure, and vulnerability: $$ \text{Risk} = \text{Hazard} \times \text{Exposure} \times \text{Vulnerability} $$ where Exposure refers to people, property, systems, or other elements present in hazard zones that are thereby subject to potential losses. Severity of Risk: The potential scale of negative consequences. High severity means large-scale impacts. Frequency of Risk: The likelihood or probability of a specific harmful event occurring. Often tied to hazard frequency. Details of Risk: Comprehensive understanding of specific potential impacts across different sectors (e.g., human casualties, economic losses, infrastructure damage, environmental degradation). 5. Capacity Definition: The combination of all the strengths, attributes and resources available within a community, society or organization that can be used to achieve agreed goals. Examples of Capacity: Physical: Safe infrastructure, emergency equipment. Social: Strong community networks, public awareness, education, local leadership. Economic: Financial reserves, diverse economy, access to credit. Institutional: Effective governance, early warning systems, trained emergency personnel, disaster plans. Natural: Healthy ecosystems providing protective services (e.g., mangroves). Capacity is crucial for reducing vulnerability and enhancing resilience. 6. Impact Definition: The consequences or effects of a disaster event, which can be direct or indirect, short-term or long-term, and positive or negative (though usually negative in the context of disasters). Types of Impacts: Human: Deaths, injuries, illness, displacement, psychological trauma. Material/Physical: Damage to buildings, infrastructure, crops, livestock. Economic: Loss of income, disruption of trade, damage to businesses, increased poverty. Environmental: Pollution, habitat destruction, resource depletion. Social: Disruption of social services, breakdown of law and order, loss of cultural heritage. 7. Prevention Definition: Activities and measures to avoid potential adverse impacts of hazards and related disasters. It expresses the concept of avoiding the adverse impacts through action taken in advance. Focus: Preventing the hazard event itself, or preventing vulnerable items from being exposed to the hazard. Examples: Dam construction to prevent floods. Strict building codes in earthquake zones. Environmental protection measures (e.g., reforestation to prevent landslides). Elimination of hazardous materials. International treaties on arms control (for human-induced hazards). 8. Mitigation Definition: The lessening of the potential adverse impacts of physical hazards (including those caused by human activities) through structural and non-structural measures. Focus: Reducing the severity of impacts when a hazard event occurs, rather than preventing the event itself. Structural Measures: Physical constructions to reduce or avoid possible impacts. Examples: Seawalls, earthquake-resistant buildings, flood embankments. Non-structural Measures: Policies, awareness, knowledge development, public commitment, and methods and operating practices. Examples: Land-use zoning, vulnerability analyses, public education, early warning systems, insurance schemes. Prevention and mitigation are often intertwined and complementary in disaster risk reduction.