 Landslides
WHAT IS A LANDSLIDE ?
It is a down slope transport of soil and rock resulting from
naturally occurring vibrations, changes in direct water content,
removal of lateral support, loading with weight, and weathering
or human manipulation of water course and slope composition.
CHARACTERISTICS
Landslides vary in
types of movement (falls, slides, topples, lateral spread, flows)
and may be secondary effects of heavy storms, earthquakes, and
volcanic eruptions. Landslides are more widespread than any other
geological event.
LIKELY IMPACT
Physical Damage
-
Anything on top
of or in the path of a Landslide will suffer damage
-
Rubble may block
roads, lines of communication or waterways. Indirect effect
may include loss of productivity of agricultural or forest
lands.
-
Flooding .
-
Reduced property
values, destruction of buildings.
-
Casualties- fatalities
may occur due to slope failure.
FACTORS
CONTRIBUTING TO VULNERABILITY
-
Settlements built
on steep slopes, softer soils and cliff tops
-
Settlements built
at the base of steep slopes, on mouths of streams from mountain
valleys.
-
Roads, communication
lines in mountain areas
-
Buildings with
weak foundations
-
Buried Pipelines
and brittle pipes.
-
Lack of understanding
of landslide hazard
PREPAREDNESS
MEASURES
Community Education after identification of areas most at risk
from landslides. The basic information required:
-
Knowledge of
where past Landslides have occurred, derived from local records
and knowledge of certain types of rocks prone to landslides.
-
Monitoring, warning
and evacuation systems
MITIGATION
MEASURES
-
Capture and drainage
of water before it reaches potential slope area
-
Underground drainage
by using sub-surface pipes
-
Land Reform by
terracing/re-shaping
Agronomic
-
Reforestation,
planting of deep rooting trees to prevent surface slips
-
Ground cover
with grass or agricultural crops
Engineering
TYPICAL POST-DISASTER
NEEDS
|
