A couple of weeks ago the Landslides Under a Microscope blog had two nice posts about Landslide Mitigation examples in Japan. The author references the book “Landslides in Japan” (1996), but I’m not sure if the photos were scanned from there, or came from the author’s own photo collection or what. But there was one post focusing on control works for landslide mitigation and another on restraint works for landslide mitigation. (Photo from Landslides Under a Microscope blog)
The Utah Geologic Survey has released a "Landslide Susceptibility Map of Utah". They apparently relied quite heavily on GIS based thresholding of existing slope angles but only after they had statistically analyzed failure angles for particular geologic units. So it sounds like they throw the known landslides, the geologic map of Utah and a DEM into the GIS a blend it all up. Perhaps a slight oversimplification!