Environmental

Studies

Topic:-

Disaster Management

Made by:- Ishu Alisha Sonu

Disaster Management

Meaning:-

A disaster is a natural or man- made

hazard resulting in an event of substantial extent

causing significant physical damage or destruction,

loss of life, or drastic change to the environment.

It is a phenomenon that can cause damage to life

and property and destroy the economic, social and

cultural life of people.

Types of disasterNatural Disasters:- Man Made Disasters:-

1.Earthquakes 1.Air,road and rail accidents

2.Cyclones 2.Wars

3.Floods 3.Riots

4.Landslides 4.Industrial accidents

Earthquakes Meaning:-

It is a violent tremor in the earth’s crust sending out the series of shock waves in all directions from its place of origin.

Example:-If you throw stone in a pond of still water,

series of concentric waves are produced on the surface of water and these waves are spread out in all directions from the point where the stone strikes the water similarly, any sudden disturbances in the earth’s crust may produce vibrations in the crust.

Causes and strength

CAUSES:-

Earthquakes are caused by sudden release of

energy in rocks. Plates in the form of rocks are

moving very slowly and it occurs when moving

plates grind and scrape against each other. The

point where earthquake originates is the “Focus ”

and the study of earthquake is called “Seismology”

STRENGTH:-

The intensity or strength of an earthquake is

measured on “Richter Scale”, the scale invented by

“Charles Richter” in 1935.

Effects Of Earthquake

Loss of life & property.

Damage to infrastructure.

Topographical changes.

Chances of fire short circuit.

Water pipes, sewers are disrupted.

Communications like telephone wires are

damaged.

Economic activities like agriculture, industry, trade

and transport are severely affected.

FloodsMeaning:-

A flood is usually caused by rain, heavy

thunderstorm, and thawing of snow.

It is considered to be a temporary condition of two or

more acres of dry land either:

Overflowed with inland or tidal waters.

Rapid or runoff of surface water.

Mudflows.

Sewer(drain) backup.

Collapse of land along the shore of a lake etc.

Factors affecting & causes

Factors Affecting Causes

Rainfall intensity. Heavy Rain.

Rainfall duration. Spring snowmelt.

Topography. Dam failure.

Soil conditions. Business growth.

Ground cover. Residential growth.

After a Flood

Stay out of flooded areas.

Reserve telephone for emergencies.

Avoid driving, except in emergencies.

Wait for authorities to issue message that it is safe

to return.

Be aware that snakes and other animals may be in

your house.

CycloneMeaning:-

A cyclone refers to a system of winds rotating

inward to an area of low atmospheric

pressure, with a counter clockwise (northern

hemisphere) or clockwise (southern

hemisphere) circulation.

A cyclone is also known as a hurricane or a

typhoon depending on what part of the world

it is in.

Safety Measures

Measures may be classified as following:

Before cyclone:-

Keep watch on weather and listen to radio or TV.

Prepare an emergency kit containing torch, dry food,

fuel lamp, waterproof bags, a first aid kit etc.

Trim dry tree branches, cut off the dead trees.

During cyclone:-

Disconnect all electrical appliances and turn off gas.

Listen to the transistor radio for updates and advice.

Don’t drive.

After cyclone:-

Do not go outside until officially advised it

is safe.

Check for gas leaks. Do not use electric

appliances.

Be careful of snake bites and carry a stick

or bamboo.

Beware of fallen power lines, damaged

bridges, buildings and trees, and do not

enter the floodwaters.

LandslidesMeaning:

A landslide is a type of "mass wasting." Mass

wasting is down slope movement of soil and/or

rock under the influence of gravity.

It effects the environment in the following

ways:

Destroys the slope/hill.

Eliminates all vegetation.

Buries houses and sometimes entire

villages.

Factors causing

landslideNatural Factors

Man-made

Factors Intensity of rainfall.

Steep slope.

Poor drainage.

Soil layers formed under

gravity.

Deforestation leading to

soil erosion.

Land use pattern.

Mining and quarrying.

Non-engineered

construction.

Effects of

landslidesLandslides leads to a lot of destruction. Some

of them are as follows:

Bury entire villages that are at the

bottom of the mountain range.

Landslides also sweep up trees, cars, and

buildings.

Landslides occur on hills near roads quite

often causing bad traffic.

Broken gas, electric, water, and sewage

lines can break.

Volcanic EruptionA volcano is an opening in the surface of the

Earth which allows hot lava, volcanic ash and

gases to escape from the magma

chamber below the surface.

Eruptions occur when underground pressure

is

released when blocks of the earth’s crust shift.

For example, earthquakes.

Measures to be takenSeveral measures to followed are:

1. Before eruption

A) Stay away from active volcano sites.

B) Be prepared for the hazards that can

accompany volcanoes like mudflows and flash

floods landslides earthquakes etc.

2. During eruption

A) Follow the evacuation order issued by

authorities.

B) Listen to a battery-operated radio or television

for the latest emergency information.

C) Protect yourself during ash fall by wearing

long-sleeved shirts and long pants and use

goggles to protect eyes.

3. After eruptionA) Turn off all heating and air conditioning

units and fans, and close windows, doors etc.

B) Do not travel unnecessarily.

C) Clear roofs of ash. Ash is very heavy and

can cause buildings to collapse.

D) It is best to stay away from the area

affected by the volcano as poisonous gases

can rise out of the ash.