Hazards, Vulnerability, Resilience and Disaster (Edexcel A-Level Geography): Revision Notes
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
A hazard becomes a disaster when:
- 10 or more people are killed And/or
- 100 or more people are affected
Understanding what Risk is
There is a relationship between risk, hazards and people which is due to several factors:
- Unpredictability → Many hazards are not predictable, people may be caught out by factors such as timing or magnitude of the event in question
- 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
- Dynamic nature of hazards → The threat that a hazard causes can change over time (get better/worse - fluctuations)
- 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
- 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:
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:
- Process of generating vulnerability on one side and
- 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
The impacts of earthquakes are often worse than volcanoes as they impact a larger area when compared to a more localised volcano ie. evacuation is possible before the hazard
| 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 |