ABSTRACT
Landslides cause an average of more than 25 fatalities and more than US$1 billion in damages each year in the United States alone, and thousands of deaths and injuries and many billions of US dollars in direct and indirect damages around the world each year. Figure 1 shows a recent landslide at La Conchita, California, which resulted in 10 fatalities and destroyed 15 expensive (on the order of US$600,000 each) homes and damaged another 16, as well as disrupted life and caused nearby property values to plummet. Figure 2 shows a landslide that happened at the same location about 10 years earlier, which resulted in 9 homes being destroyed, as well as life disruption and significant property value decreases (which eventually recovered as memory faded), but no fatalities. On the other hand, most landslides have no significant impact, simply rearranging the topography. The primary questions that need to be addressed are:
• Why do landslides occur when they do, how can we predict them, and what should we do to prevent or at least control them?
