DISASTER READINESS AND RISK REDUCTION REVIEWER.docx

DISASTER READINESS AND RISK REDUCTION REVIEWER

LESSON 1: BASIC CONCEPTS OF DISASTER AND DISASTER RISK

1.1 Concept of Disaster

• A disaster is a sudden, catastrophic event that causes significant disruption, damage, and loss of life. It occurs when a hazard interacts with exposure and vulnerability.

Key Definitions:

• Hazard – A natural or human-made event that has the potential to cause harm (e.g., typhoons, earthquakes, chemical spills).
• Exposure – The people, property, and environment that are at risk of being affected by a hazard.
• Vulnerability – The inability of a community or system to withstand or cope with a hazard.

Why is the Philippines one of the most disaster-prone countries?

1. Warm Ocean Water – The country is near the equator, with warm waters fueling typhoons (~20 typhoons per year).
2. Coastal Homes – 60% of the population lives in coastal areas, increasing risk.
3. Deforestation – Loss of trees leads to mudslides and landslides.
4. Ring of Fire – Prone to earthquakes and volcanic eruptions.
5. Underdevelopment – Poor infrastructure and inadequate disaster response.

When Does a Natural Event Become a Hazard?

• A natural event is only considered a hazard if it poses a threat of damage, injury, or death to people and property.
• Example: A volcanic eruption in an uninhabited area is NOT a disaster. It becomes one only when it affects people.

When Does a Hazard Become a Disaster?

• A disaster occurs when a hazard strikes a vulnerable, exposed population and causes significant damage or casualties.
• Formula: Disaster Risk = Hazard × Exposure × Vulnerability

1.2 Disaster Risk

Understanding Disaster Risk:

• Disaster risk refers to the potential loss of lives, injuries, property, and economic damage due to a hazard.
• Risk Assessment helps identify the impact of hazards on people, infrastructure, and the environment.

Factors Determining the Magnitude of a Disaster:

1. Severity of the Hazard (e.g., intensity of an earthquake, strength of a typhoon).
2. Level of Exposure (number of people and properties at risk).
3. Degree of Vulnerability (preparedness, infrastructure quality, government response).

Elements of Disaster Risk:

• Hazard: Earthquakes, typhoons, floods, etc.
• Exposure: People, property, and infrastructure at risk.
• Vulnerability: Lack of preparedness, weak structures, poor governance.

Risk Reduction Strategies:

• Reducing Exposure – Relocating people away from high-risk areas.
• Reducing Vulnerability – Strengthening buildings, improving preparedness, enforcing laws.

1.3 Nature and Effects of Disasters

Characteristics of Disasters:

• Unexpected or sudden (can happen with little or no warning).
• Causes widespread damage (affects multiple areas at once).
• Requires emergency response (government, NGOs, international aid).
• Affects multiple sectors (social, economic, environmental).

Impacts of Disasters:

1. Physical Impact

• Deaths, injuries, destruction of buildings and homes.
• Infrastructure damage (roads, bridges, hospitals, power lines).

1. Medical Effects

• Epidemics, emotional trauma, increase in health risks.

1. Economic Impact

• Loss of jobs and businesses.
• Disruption of supply chains and transportation.

1. Social and Political Impact

• Increases poverty, affects marginalized groups the most.
• Can lead to political instability if response is inadequate.

1. Environmental Impact

• Deforestation, water contamination, and climate change.

CHAPTER 2: EXPOSURE AND VULNERABILITY

2.1 Elements at Risk (Exposure)

Elements at Risk:

• People, buildings, infrastructure, and economic activities that can be affected by hazards.

Formula for Physical Exposure:

Physical Exposure = Hazard Probability × Population at Risk

Types of Exposure:

1. Social Exposure: Population density, health systems, migration.
2. Environmental Exposure: Location, infrastructure, land use.
3. Economic Exposure: Business activities, employment, economic stability.

Categories of Infrastructure at Risk:

1. Essential Facilities: Hospitals, schools, government offices.
2. Industrial and Hazardous Facilities: Power plants, chemical storage.
3. Transportation Systems: Roads, bridges, airports, ports.
4. Utility Lifelines: Water systems, communication networks, electricity grids.

2.2 Vulnerability of Exposed Elements

What is Vulnerability?

• The degree to which a community, structure, or system is unable to cope with or recover from a disaster.

Factors of Vulnerability:

1. Social Vulnerability

• Most vulnerable groups:
• People with disabilities
• Children and the elderly
• Single parents and the unemployed
• Indigenous and minority groups
• Homeless individuals

1. Environmental Vulnerability

• Urbanization in hazardous areas.
• Deforestation increasing disaster risks.
• Poor land use planning (informal settlers in flood zones).

1. Economic Vulnerability

• Poor households lack resources for preparedness.
• Informal economies suffer major losses.
• Women tend to have less financial stability after disasters.

Measuring Vulnerability:

• Expressed as a value between 0 and 1 (0 = no vulnerability, 1 = highest vulnerability).
• People: Ratio of casualties/injured to total population.
• Buildings: Cost of repairs/damage severity.