Vulnerability's Three Dimensions Introduction

There are three dimensions of vulnerability: exposure, sensitivity, and adaptive capacity. Exposure is the degree to which people and the things they value could be affected or "touched" by coastal hazards; sensitivity is the degree to which they could be harmed by that exposure; and adaptive capacity is the degree to which they could mitigate the potential for harm by taking action to reduce exposure or sensitivity.

The expression "things they value" not only refers to economic value and wealth, but also to places and to cultural, spiritual, and personal values. In addition, this expression refers to critical physical infrastructure such as police, emergency, and health services buildings, communication and transportation networks, public utilities, and schools and daycare centers. It also refers to social infrastructure such as extended families, neighborhood watch groups, fraternal organizations, and more. The expression even refers to such social factors as economic growth rates and economic vitality. People value some places and things for intrinsic reasons and some because they need them to function successfully in our society.

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Figure 10.3: Critical infrastructure like this nuclear power plant in Ikata, Japan is vulnerable to many coastal hazards.
Credit: Wikipedia: Kata Nuclear Power Plant / https://creativecommons.org/licenses/by-sa/3.0/ CC BY-SA 3.0

Some people and the things they value can be highly vulnerable to low-impact coastal hazards because of high sensitivity or low adaptive capacity, while others can have little vulnerability to even high-impact coastal hazards because of insensitivity or high adaptive capacity. Coastal hazards result in highly variable impact patterns because of these variations in vulnerability in time and space.

Some groups of people are inherently more vulnerable to coastal hazards than others. The very old or very young, the sick, and the physically or mentally challenged are often vulnerable. Disadvantaged groups, such as minorities, the poorly educated, or non-native speakers, are usually more vulnerable than the majority, better-educated, native language-speaking population. Women — who typically spend more time and effort on care-giving to parents, children, and the sick than men do — are generally more vulnerable because that care-giving exposes them more to coastal hazards.

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Figure 10.4: A person in a wheelchair waits for help at the Superdome shelter in the aftermath of Hurricane Katrina. The physically challenged are often more vulnerable to coastal hazards.
Credit: FEMA News Photo

The most vulnerable groups often combine these categories. Examples include the poor — who in many societies are also more likely to be old, minority, non-native speaking, and/or female. Another example is the single-mother household. Already particularly vulnerable because a single parent is responsible for both caregiving and providing the family income, this vulnerability is often compounded by poverty or minority status, which can make it more difficult to access social services.

The concept of resilience is important to understanding the adaptive capacity dimension of vulnerability to coastal hazards. Resilience refers to the ability of a human system (such as a municipal water system and the community that supports it) to withstand contemporary shocks and to anticipate and plan for future shocks. Resilient systems have the ability to learn from past experiences and to use that knowledge when confronting problems. Systems with high adaptive capacity are therefore resilient and able to reconfigure themselves to deal with coastal hazards. Systems with low adaptive capacity are much less resilient and much more vulnerable to coastal hazards.