1 . Landslides are typically ` classified by the type of movement that occurs (Table 253-1) .
Complex landslides consist of two or more movement types occurring in succeeding
stages .
2. The destructive significance of a landslide is affected by the velocity of movement,
as described in Table 253-2 .
3. Landslides may be caused by susceptible geologic, morphologic, or other physical
conditions such as heavy rainfall . Human activity such as construction or removal of
protective vegetation can also cause landslides . Table 253-3 lists likely causes of
landslides .