From Earthquake Magazine, an interesting description of risk modeling — Risky business: Modeling catastrophes, Oct. 2012. Some excerpts:
Natural hazards — earthquakes, tropical cyclones and thunderstorms, for example — occur with considerable frequency around the world. Fortunately, most events are either not intense enough or too remote to cause damage. But the probability that a given natural hazard could become a natural disaster is higher today than at any previous point in history.
This rise in the probability of catastrophes is primarily a result of population growth, as opposed to changes in the frequency or intensity of natural hazards. As the number of people grows — currently about 7 billion — so does the infrastructure associated with the population, such as houses, bridges and cars. Thus, if a natural hazard strikes, there are simply more people and more things in harm’s way. Additionally, people are continuing to move to areas of high hazard, including wildland-urban interfaces such as in the canyons of Southern California and the hills of Boulder and Colorado Springs, Colo., and coastlines. Nearly 67 percent of the world’s population currently lives within 160 kilometers of a coastline, and that number is expected to reach 75 percent in the next couple of decades, according to the U.S. National Academies of Science.
- EARTH: Risky business: Modeling catastrophes (eurekalert.org)