Environmental Studies

Topic:-Disaster ManagementMade by:- Ishu Alisha Sonu

Disaster ManagementMeaning:-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 accidents2.Cyclones 2.Wars3.Floods 3.Riots 4.Landslides 4.Industrial accidents

EarthquakesMeaning:- 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 CausesRainfall 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 landslide

Natural 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 landslides

Landslides 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 eruptionA) 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 eruptionA) 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.