Vulnerability
Vulnerability is defined by the ISDR as “conditions determined by physical, social, economic, and environmental factors or processes, which increase the susceptibility of a community to the impact of hazards.” Vulnerability can therefore be high or low depending on said conditions, for example people living in low lying areas experience higher vulnerability to flooding than people who live higher up.
There are different types of vulnerability, here are a few examples:

• Poorer families may live in squatter settlements because they cannot afford to live in safer (more expensive) areas. This is called Economic Vulnerability.
• Wooden homes which are less likely to collapse in an earthquake, but are more vulnerable to fire. This is called Physical Vulnerability.
• When flooding occurs some citizens, such as children, elderly and differently able, may be unable to protect themselves or evacuate if necessary. This is called Social Vulnerability.
• The waves generated by hurricanes are larger and more powerful than normal. These waves can cause significant damage to coral reefs. This is called Environmental Vulnerability.

As you can see there is significant overlap among these types of vulnerabilities, which is why when conducting vulnerability assessments, all these factors must be considered.

Risk
Risk refers to the “probability of harmful consequences, or expected losses (deaths, injuries, property, livelihoods, economic activity disrupted or environmentally damaged) resulting from interactions between natural or human induced hazards and vulnerable conditions” (ISDR).
The formula for specific risk is as follows:
Risk= Hazards x Vulnerability
There are different ways of dealing with risk. Here are a few options:

• Risk Acceptance: an informed decision to accept the possible consequences and likelihood of a particular risk.
• Risk Avoidance: an informed decision to avoid involvement in activities leading to risk realization.
• Risk Reduction refers to the application of appropriate techniques to reduce the likelihood of risk occurrence and its consequences.
• Risk Transfer involves shifting of the burden of risk to another party. One of the most common forms of risk transfer is Insurance.

Vulnerability and Risk Assessments
Before steps can be taken to reduce risk and vulnerability, they must first be understood. Vulnerability Assessments and Risk Analyses allow for the identification of areas of critical concern and can help to guide mitigation efforts.
There are many methodologies that exist today on how to conduct both risk and vulnerability assessments, organizations such as the National Oceanic and Atmospheric Administration have even developed their own tools to aid this process.
It is important to keep in mind that conditions may vary from location to location, and it is therefore useful to select assessment tools which are appropriate to the area being studied, for example Community Vulnerability Assessment Tools (CVAT) can be used me assessing villages, while tools that cater to a larger scale can be used for assessments at a national level.
Data collection is a key part of conducting risk and vulnerability assessments. Some of the data that should be collected are:

• Hazards
• Critical facilities
• High risk areas
• Areas of environmental sensitivity
• Mitigation opportunities

The greater the accuracy of the data collected, the more precise the assessment will be.

 

 For Further Information:

• Threat/Vulnerability Assessments and Risk Analysis - Whole Building Design Guide
• Risk and Vulnerability Assessment Tool
• Community Vulnerability Assessment Tool