Causes of Landsliding

Geologists use a variety of classification schemes to describe causes of landslides. Because of wide variety of causes, no single scheme has yet been developed that address or describe all types of landslides. Even the terms assigned to types of landslides are undergoing standardization among geological and scientific international agencies. Some of these will be illustrated in the guidebook, but for an example of a classification scheme that has been widely used outside the U.S. see the following:

External

1. Geometrical change

1. Gradient

2. Height

3. Slope length

2. Unloading

1. Natural

2. Human-induced

3. Loading

1. Natural

2. Human-induced

4. Shocks and Vibrations

1. Single

2. Multiple/continuous

Internal

5. Progressive failure (internal response to unloading, etc.)

1. Expansion, swelling

2. Fissuring

3. Strain softening

4. Stress concentration

6. Weathering

1. Physical property changes, swelling

2. Chemical changes

7. Seepage Erosion

1. Removal of cements

2. Removal of fines

8. Water Regime Change

1. Saturation

2. Rise in water table

3. Excess pressures

4. Drawdawn

Source: The Royal Academy of Engineering. 1995. Landslides Hazard Mitigation. Westminster, London: The Royal Academy of Engineering.