Hazards, Vulnerability, Resilience and Disaster

Hazard → A perceived natural/geophysical event that has the potential to threaten both life and property

Disaster → A serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources

Adaptation → Changes to ways of doing things so future hazards have less impact

Understanding what Risk is

There is a relationship between risk, hazards and people which is due to several factors:

1. Unpredictability → Many hazards are not predictable, people may be caught out by factors such as timing or magnitude of the event in question
2. Lack of places to go → People may be forced to stay in the hazardous area due to there being a lack of alternative places to go due to lack of money, skills, knowledge or even an area to move to
3. Dynamic nature of hazards → The threat that a hazard causes can change over time (get better/worse - fluctuations)
4. Cost-benefit → The benefits of a hazardous area (such as good soil fertility) may outweigh the risk of a potential volcano eruption as it has not happened in so many years
5. Acceptance of risk → The acceptance that the risk as something that will happen no matter what

The Hazard Risk Equation

Here is the equation written in block format:

$$\text{Risk} = \text{hazard} \times \text{exposure} \times \left( \frac{\text{vulnerability}}{\text{manageability}} \right)$$

Resilience & Vulnerability

Resilience → How well a population can recover from a hazardous event

Adaptations:

• Identification of risks of potential hazards

• Planning about what to do should a hazard occur

• Implementation of plans to help decrease ↓ impact Recovery:

• Stockpiling essentials (medication, water, food)

• Resources for restoration phase Vulnerability → The extent to which a community could be damaged or disrupted by a hazard

Factors include:

• Location of buildings
• Presence of advanced warning systems
• How involved locals are in planning and preparation
• People's ability to prepare, react & withstand the impacts of a hazard
• How well people understand hazards

The Pressure and Release (PAR) Model

The risk people face w/ regards to a hazard is determined by the hazard itself & how vulnerable the population & infrastructure is.

The idea of the PAR Model is that a disaster is the intersection of two processes:

6. Process of generating vulnerability on one side and
7. The natural hazard event on the other

The PAR Model:

Root Causes	Pressures:	Unsafe Conditions	Natural Hazards & Location
Limited Access To: • Power • Structures • Resources Ideologies: - Political & Economic systems • Poor governance	Lack of: • Appropriate skills • Training • Local investment • Press freedom Macro Forces: • Rapid population change • High migration • Rapid urbanisation • Deforestation • Arms expenditure • Debt repayment schedules	• Fragile physical environment • Fragile local economy • Vulnerable society • Poor location of settlements • Weak buildings & infrastructure	Geography: • Hazard location zones spatial extent • Magnitude • Timing & Frequency • Onset speed of hazard Tectonics: • Plate movements • Earthquakes • Volcanoes

• Root causes create vulnerability (such as lack of resources = lack of training of population)
• The dynamic pressure (lack of training) creates unsafe conditions in the physical and social environments of the people & groups most susceptible to vulnerability & risk
  • Physically unsafe - Buildings with low resistance
  • Socially unsafe - Inadequacies in the disaster-preparedness measures

The Social & Economic Impacts of Tectonic Hazards

These vary considerably in terms of time, level of development and geographical region.

Levels of development measured by:

• Economic - GDP
• Social - Levels of education & healthcare
• Social & economic - HDI
• Political - How involved people are in decision making
• Environmental - Levels of habitat destruction etc

Social impact	Economic impact
• Developing & emerging countries often have higher losses of life than developed countries when comparing similar hazardous events	• Developing & emerging countries often have higher costs than developed countries when comparing similar hazardous events
• Infrastructure not as strong, therefore often more building collapses warranting higher rebuilding costs	• Better technology & warning systems means they are better prepared
	• Developing countries only tend to experience extreme costs when the hazard is focused in urban areas (where the majority of building and settlements are)
	• Costs to emerging countries are increasing because they have increasing construction and rapid urban growth