Chapter 3 - Risk and vulnerability

Abstract

Citizens collectively face risks from a range of large-scale hazards. Risk is the interaction of hazard consequences and likelihood. Using this formula, hazards are compared and ranked, allowing disaster managers to determine the most effective and appropriate treatment options. The goal of risk analysis is a standard measurement of likelihood and consequence, whether quantitative or qualitative. Consequence describes hazard effects on humans, built structures, and the environment. Losses may be direct or indirect, and tangible or intangible. Hazard likelihood and consequences can change considerably over time. These trends can be incremental or extreme and can occur suddenly or over centuries. Risk evaluation is conducted to determine the relative seriousness of risks, and to compare and prioritize them. Disaster managers must decide what risks to treat, what risks to prevent at all costs, and what risks to disregard. These decisions are based on risk acceptability. The personal factors that dictate risk acceptability are guided by risk perception. Vulnerability is a measure of the propensity of an object, area, individual, group, community, country, or other entity to incur the consequences of a hazard, and is the result of physical, social, economic, and environmental factors.