The presentation is about the Causes, Effects, and Mitigation of Landslide and Volcanism

1. Presentation on Causes,
Effects and Mitigation of
Landslide and Volcanism

2. Human causes
Excavation
Loading
Draw-down
Land use change
Water management
Mining
Quarrying
Vibration
Water leakage
Deforestation
Land use pattern
Pollution
Physical causes
Intense rainfall
Rapid snow melt
Prolonged precipitation
Rapid drawdown
Earthquake
Volcanic eruption
Thawing
Freeze-thaw
Ground water changes
Soil pore water pressure
Surface runoff
Seismic activity
Soil erosion
Geological causes
Weathered Materials e.g heavy
rainfall
Sheared materials
Jointed or fissured materials
Adversely orientated discontinuities
Permeability contrasts
Material contrasts
Rainfall and snow fall
Earthquakes
Working of machinery
Morphological causes
Slope angle
Uplift
Rebound
Fluvial erosion
Wave erosion
Glacial erosion
Erosion of lateral margins
Subterranean erosion
Slope loading
Vegetation change
Erosion

3. A)Direct Effects:
• Physical Damage-
- may block roads, supply
lines (telecommunication, electricity,
water, etc.) and waterways.
- Loss of property, infrastructure and
lifeline facilities, Resources, farmland and places
of cultural
importance.
• Causalities
deaths and injuries to people and
animals.
B) Indirect Effects:
- Flooding
- Loss in productivity of agricultural or
forest lands,
- Reduced property values,
- Loss of revenue,
- Increased cost,
-Adverse effect on water quality

4. Landslide mitigation
refers to lessening
the effect of
landslides by
constructing various
man made projects
on slopes which are
vulnerable to
landslides.
Therefore, slope
stabilization
methods in rock or
in earth, can be
collocated into three
types of measure:
Geometric
methods, in which
the geometry of the
hillside is changed
(in general the
slope);
Hydrogeological
methods, in which an
attempt is made to
lower the
groundwater level or
to reduce the water
content of the
material;
Chemical and
mechanical methods,
in which attempts are
made to increase the
shear strength of the
unstable mass or to
introduce active
external forces (e.g.
anchors, rock or
ground nailing) or
passive (e.g.
structural wells, piles
or reinforced ground)
to contrast the
destabilizing forces.

5. • The buoyancy of the magma,
• The pressure from the exsolved gases
in the magma and
• The injection of a new batch of magma
into an already filled magma chamber.
• Plate tectonics.
Although
there are
several factors
triggering a
volcanic
eruption, four
predominate:

6. Primary Effects
• Pyroclastic Flows
• Volcanic Gases
• Lava Flows
• Tephra
Secondary effects
• Lahars
• Landslides
• Flooding
• Homelessness.
• Food / water supply interrupted.
• Businesses forced to close.
• Cost of insurance claims.
• Unemployment and Long-term
issues with the tourism industry

7. Wear an
emergency mask
or hold a damp
cloth over face.
If you are not
evacuating, close
windows and doors and
block chimneys and
other vents, to
prevent ash from
coming into the house.
Be aware that ash may
put excess weight on
your roof and need to
be swept away. Wear
protection during
cleanups.
As much as
possible, stay
away from
active
volcanoes.
Keep goggles
and a mask in an
emergency kit,
along with a
flashlight and a
working,
battery-
operated radio.

8. Credits:
– Dr. M Bodrozzoha Mia.
– Edward A. Keller