Transcript types of disaster

CONTENTS
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DISASTER
TYPES OF DISASTER
EARTHQUAKES
LANDSLIDES
FLOODS
CYCLONES
REFERENCES
DISASTER
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The term ‘Disaster’ owes its origin to the French word
‘Desastre’ which is the combination of two terms ‘des’
meaning bad or evil and ‘astre’ meaning star . The
combination expression is ‘Bad or Evil Star’.
A catastrophe, sudden, calamitous event bringing great
damage, loss, destruction and devastation to life and
property by natural or man-made causes.
TYPES OF DISASTER
Two Types – Natural and Manmade
Natural disasters:
 Flood
 Cyclone
 Earthquake
 Landslides
Manmade Disaster
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Setting of fires
Epidemic
Deforestation
Chemical pollution.
Wars
Road / train accidents, riots
Food poisoning
Environmental pollution
EARTHQUAKES
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Ground shaking – back-&-forth motion , caused
by the passing vibratory waves.
Soil failures – caused by shaking e.g. landslides .
Surface fault ruptures, such as cracks , vertical
shifts.
Tidal waves ,i.e. large waves on the surface of
bodies of water that can cause major damage to
shoreline areas.
EFFECTS ON BUILDINGS
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As vibrations & waves continue to move
through the earth –buildings ,set in motion.
Each building response differently ,acc.to its
construction.
When waves strike ,earth moves backward &
forward .
The lower part of building moves with the earth.
The upper portion –initially remains at rest.
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The upper portion tries to catch up with the
bottom but as it does so, the earth moves in the
other direction – ‘whiplash effect’.
Taller buildings also tend to shake longer than
short buildings.
PROTECTION MEASURES
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The building should have a simple rectangular
plan.
Long walls should be supported by reinforced
concrete columns.
Large buildings having plans with shapes like
T,U,L and X.
It should preferably be separated into
rectangular blocks by providing gaps in between.
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Doors and window openings in walls ,
preferably be small & more centrally located.
The location of openings should not be too
close to the edge of the wall.
LANDSLIDES
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2.
Landslides occur because of the interplay of
several factors.
Natural factors :- Intensity of rainfall, Steep
slopes, Poor drainage, Stiffness of slopes etc.
Manmade factors:- Deforestation leading to
soil erosion etc.
MOST VULNERABLE HOMES
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Existing landslides area.
Steep natural slopes.
Area in or at the mouths of drainages.
Houses constructed near foothills.
PROTECTION MEASURES
FROM DAMAGE TO BUILDINGS
(a) Site selection:
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Safe area – that have not moved in the past .
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Houses built at the toe of steep slopes.
(b) Signs and warnings:
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Doors or windows stick for the first time.
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New cracks appear on plaster,tile,brick.
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Underground utility lines break.
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Fences, retaining walls, utility poles or trees tilt or
move.
(c) Preventive action:
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Proper development.
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Sound construction techniques.
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Seasonal inspections.
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Regular maintenance of drainage facilities.
(d) Protect vulnerable area:
Keep surface drainage water away from vulnerable areas
(steep slopes, loose soils & non-vegetated surfaces.)
(e) Intercept surface water.
(f) Stabilize slopes:
1. Improve soil’s ability .
2. Straw, woodchips applied to a depth of at least
one inch.
FLOODS
Water is a source for all life forms . Without water
no life is sustainable. ‘How tragic it is’ , when
water in the form of floods takes away thousand
of human and cattle lives. More than one million
huts and poor houses are lost every year in
floods in India. CAN WE PREVENT THIS
LOSS ????????????
MOST VULNERABLE HOMES
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Building – constructed with earth –based
materials or using stone & brick in mud mortar .
The huts made from biomass materials.
The occupation of areas within the flood plain
of rivers has increased vulnerability.
EFFECT ON BUILDINGS
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The houses are commonly destroyed so severely
that their reconstruction is not feasible.
It is constructed out of light weight material .
Damage caused by inundation of house .
Undercutting of houses.
Damage caused by debris.
PROTECTION MEASURES
FROM DAMAGE TO BUILDINGS
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To avoid residing on river banks & slopes on
river sides.
To build at least 250 mts away from the sea
coast .
To build proper drainage system in all flood
prone areas.
To construct the building with a plinth level
higher than the known high flood level.
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To construct the whole village on a raised plat
form higher than the high flood level.
To construct buildings on stilts or columns with
wall – free space at ground level permitting free
flow of water.
CYCLONES
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Cyclones pose a major threat to life and
property in many parts of the world. Every year
these sudden, violent cyclones bring widespread
devastation to coastlines and islands lying in
their erratic paths. A windstorm's destructive
work is done by the high wind; flood producing
rains and associated storm surges.
MOST VULNERABLE HOMES
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Location
Light weight
Older buildings
Poorly constructed concrete blocks
Urban and rural communities on low islands
Effected by the velocity of cyclone wind at
ground level
EFFECTS ON BUILDINGS
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Uprooting of trees
Damage to signposts , electric poles, etc
Damage to improperly attached windows
Damage to roof/lintel projections
Failure of improperly attached parapets
Overturning failures of compound walls of
various types
PROTECTION MEASURES
FROM DAMAGE TO BUILDINGS
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Site selection
Platforms and orientation
Foundations:- (a) effect of surge or flooding,
(b) Building on stilts
Wall openings
Glass panelling
Roof architecture
REFERENCES
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www.google.com
www.bte.gov.au
http :// gujarat-earthquake .gov.in/
Text book of disaster management
www.wikipedia.com