Many areas of the world are at risk from landslides and their consequences; rainfall-triggered landslides particularly affect developing countries in the tropics. Rapid urbanization and the associated growth of unauthorized and densely populated communities in hazardous locations, such as steep slopes, are powerful drivers in a cycle of disaster risk accumulation. Frequently, it is the most socioeconomically vulnerable who inhabit landslide-prone slopes--thus increasing their exposure to landslide hazards and often increasing the hazard itself. There is growing recognition that urban...