land slides

Landslide- A landslide or Landslip is

a geological phenomenon which includes a wide range of ground movement

HELP!!!!

Landslide

Landslides occur when the stability of a slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of

factors, acting together or alone. Natural causes of landslides

include:

Landslide Causes:

groundwater  pressure acting to destabilize the slope.

Loss or absence of vertical vegetative structure, soil nutrients, and soil structure (e.g. after a wildfire).

erosion of the toe of a slope by rivers or ocean waves.

weakening of a slope through saturation by snowmelt, glaciers melting, or heavy rains.

earthquakes adding loads to barely stable slope. Earthquake-caused liquefaction destabilizing 

slopes. volcanic eruptions.

Landslide Causes:

Landslide

“Landslides are aggravated by human activities”

Landslide

deforestation, cultivation and construction, which destabilize the already fragile slopes.

vibrations from machinery or traffic. Blasting. earthwork which alters the shape of a slope, or

which imposes new loads on an existing slope in shallow soils, the removal of deep-rooted 

vegetation that binds colluvium to bedrock. Construction, agricultural or forestry activities

(logging) which change the amount of water which infiltrates the soil.

Human Causes:

- Sand boils or Sand Volcanoes occur when water under pressure wells up through a bed of sand. The water looks like it is "boiling" up from the bed of sand

Sand Boil

Sand boils can be a mechanism contributing to levee failure during floods. This effect is caused by a

difference in pressure on two sides of a levee or dike, most likely during a flood.

This process can result in piping, whereby the removal of soil particles

results in a pipe through the embankment. The creation of the pipe

will quickly pick up pace and will eventually result in failure of the

embankment.

Sand Boils Causes:

A sand boil is difficult to stop. The most effective method is by creating

a body of water above the boil to create enough pressure to slow the flow of water. A slower flow will not be able to move soil particles. The body of water is often created with sandbags forming a ring around the

boil

Sand Boils Prevention:

THE END