Hazard is best viewed as a naturally occurring or human-induced process or event with the potential to create loss, i.e. a general source of danger. Risk is the actual exposure of something of human value to a hazard and is often regarded as the combination of probability and loss. Thus, we may define hazard (or cause) as a potential threat to humans and their welfare and risk (or consequence) as the probability of a specific hazard occurrence. The distinction was illustrated by Okrent (1980) who considered two people crossing an ocean, one in a liner and the other in a rowing boat. The main hazard (deep water and large waves) is the same in both cases but the risk (probability of drowing) is very much greater for the person in the rowing boat. Thus while an earthquake hazard can exist in an uninhabited region, an earthquake risk can occur only in an area where people and their possessions exist. People, and what they value, are the essential point of reference for all risk assessment and for all disasters (Smith 1996, 5).