WHAT IS A LANDSLIDE?
A landslide is defined as a perceptible downward and outward movement of slope-forming soil, rock, and vegetation under the influence of gravity. WHAT CAUSES A LANDSLIDE? Landslides can be triggered by both natural and human-induced changes in the environment. These changes may result from weaknesses in the composition or structure of the rock or soil, heavy rain, or changes in ground-water level, seismic activity, or construction activity. Human- induced landslides may result from changes in slope caused by terracing for agriculture, cut-and-fill construction for highways, building construction, mining operations, and changes in irrigation or surface runoff. TYPES OF LANDSLIDES Rock falls are rapid movements of bedrock characterized by free-fall, bouncing, and rolling. A topple is a block of rock that tilts or rotates before falling to the slope below. Slides are movements of soil or rock along a distinct surface of rupture which separates the slide material from the more stable under
