The term "landslide" describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing. The pictures shows a graphic illustration of a landslide, with the commonly accepted terminology describing its features.
The various types of landslides can be differentiated by the kinds of material involved and the mode of movement. A classification system based on these parameters is shown in . Other classification systems incorporate additional variables, such as the rate of movement and the water, air, or ice content of the landslide material.
Although landslides are primarily associated with mountainous regions, they can also occur in areas of generally low relief. In low-relief areas, landslides occur as cut-and-fill failures , river bluff failures, lateral spreading landslides, collapse of mine-waste piles (especially coal), and a wide variety of slope failures associated with quarries and open-pit mines. The most common types of landslides are described as follows in the pictures above.
