land slides
DESCRIPTION
all about land slidesTRANSCRIPT
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:
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