This map, reproduced from U.S. Geological Survey Open-File Report 97-289, shows areas of landslide occurrence and susceptibility. Red areas indicate high incidence of landslides. Light beige is low landslide incidence, copper-colored is moderate. The blue-green areas indicate moderate landslide susceptibility, but low incidence. Light brown is high susceptibility/low incidence. Light red indicates high susceptibility/moderate incidence.
Image Credit: U.S. Geological Survey
Rockfalls and Slides
The slopes above streams and rivers are subjected to a variety of processes that cause them to recede and retreat from the river or stream channel. These processes, collectively called mass wasting, can be classified according to rapidity of movement and according to the type of materials that are transported.