Class 10 Disaster Management All Chapters Summary / Short Summary

Disaster Management

A disaster is a destructive event that occurs suddenly and involves loss of life and property. Disasters can be of two types, natural and man-made.

Earthquakes, volcanic activity, tsunamis, floods, cyclones, landslides, avalanches and droughts are natural disasters. Some of the man-made disasters are: bomb explosions, terrorism, war or civil war, leakage of poisonous chemicals, breach in dams, air or water pollution, industrial accidents and epidemics.

Disaster Management refers to the measures taken for the safety and protection of life and property from natural or man-made disasters.

This means being prepared for disasters, fighting disasters effectively, ensuring the safety of life during disasters and helping in rebuilding society after the disaster.

Earthquakes

An earthquake is a sudden tremor or movement of the earth's crust, originating at or below the surface. The outer layer of the earth is solid and is divided into many sections known as plates on which all the continents stand.

The plates float over the molten magma flowing beneath the earth’s crust, moving slowly. Sometimes, during the course of their movements, these plates move against each other. Earthquakes occur on the edges of these plates along fault lines where the plates collide or try to slide past each other.

Earthquakes are also caused by explosive volcanic eruptions. There are other man-made causes of earthquakes like vibrations caused by big rocks falling down hills because of erosion, hollow parts of mines falling down due to dissolution of minerals by water and due to nuclear explosions.

The point of origin of the earthquake within the crust or mantle is called the seismic focus. The location of the earthquake is referred to as the point on the surface of the earth, vertically above the seismic focus called the epicentre.

The extent of damage that an earthquake can cause depends on its magnitude. Earthquakes can be measured with a device called the seismometer; a device which also records is known as a seismograph.

The magnitude of the earthquake is measured through an instrument called ‘Richter Scale’.
The under-sea earthquakes, give rise to giant waves called the tsunami, which cause great deal of destruction along the coasts.

Two thirds of all the earthquakes occur in the ‘Ring of Fire’ in the Pacific Ocean. Kashmir, western Himalayas, middle Himalayas, northeast India, the plains of the Ganga and Indus, Rajasthan, Gujarat, Lakshadweep, Andaman and Nicobar Islands are the earthquake- prone regions in India.

Measures for preparing against earthquakes:

In absence of an early warning system, the information about earthquakes and their intensity should be shared with the public through radio, television and newspapers.

Buildings must be based on earthquake-resistant techniques and all under-construction houses should be made to follow the building guidelines.

Buildings to be constructed over concrete and iron pillars built deep in the ground.

In emergency, water, ration, first-aid kits, radios, flash lights, battery, blankets, jackets and fire extinguishers should be stored in safe places.

To do things when an earthquake strikes:

Remain calm

Take cover under a solid surface like a table, or stand in the doorway if inside building or house

Move to an open space away from trees, electric poles and buildings if outside

Switch off the gas and electric supply in the house during a quake and don not use elevators.

After the quake the affected people should be given immediate medical help and vaccinated to stop

epidemics from spreading.

Transport and communication facilities should be restored as soon as possible so that rescue teams can reach the earthquake-hit area.

Police and paramilitary forces should be deployed to protect properties which had to be abandoned from theft.

Volcanoes, Tsunamis and Cyclones

Volcano eruptions happen when the molten rocks or lava in the earth’s crust come out along with gases and steam flow on the earth’s surface.

There are three types of volcanoes: active, dormant and extinct. The active volcanoes erupt from time to time. The dormant volcanoes were active in the past, though they have not shown any activities for a long time. The extinct volcanoes do not have any recorded history of being active. Most of the volcanoes are found in the Ring of Fire in the Pacific Ocean.

Earthquakes and volcanic eruptions cause a sudden disturbance at the base of the ocean, causing abrupt displacement of water. Such activities produce very high waves which are called Tsunamis. Even though tsunamis or big earthquakes cannot be precisely predicted, there are automated early warning systems that can provide warnings immediately after an earthquake in time to save lives.

A cyclone is an egg-shaped air formation that moves in the form of swirling winds. It has low air pressure at its centre but very high pressure at the surface. Since air moves from a region of high pressure to a region of low pressure, cyclones cause high winds and heavy rainfall.

Some precautions from cyclone are:

Using early warning system. The Indian Meteorological Department issues cyclone warnings in India.

Cyclone proof structures should be built in coastal areas.

Planting trees also help in fighting cyclones

All about Floods

Floods occur when land gets submerged under water due to various causes like excessive rain, overflowing rivers, increase in water in reservoirs, cyclones, tsunami, sea tides and melting of glaciers. Floods caused by cloud bursts, bursting of dams, or tsunamis are called flash floods.

Flooding damages crops and this leads to a shortage of food. Shortage of drinking water also arises as the sources of fresh water get contaminated by the flood water, causing epidemics.

Any flood is preceded by a threat period known as the Probability Period. This allows the authorities to issue warnings and plan evacuation. In India, the Central Water Commission has 132 forecasting stations covering all inter-state flood prone rivers.

Steps to be taken before floods to reduce the damage:

Mapping of major rivers, their flood plains and basins

Construction of artificial embankments like dikes and levees to divert flood water

Stream behaviour should also be studied for charting of rivers and other water bodies

Artificial reservoirs with sluice gates and sand bags to be built to block the flow of water

Low grounds or viaducts can be created to carry water in a certain direction or underground

Trees should be planted in the catchment areas to stop soil erosion

In case of an impending flood, all attention should be paid towards the safety of dams. Encroachments of human settlements on river banks should also be prevented.

Precautions in case of floods:

Rush to high and safe places and ensure to have clean drinking water

Do not drive if water levels are rising in an area

Keep away from rivers, dams and bridges during floods

Clean and disinfect the houses

Get medical help in case of water borne disease

Injured or sick animals should be treated by veterinarians

Plant more trees to prevent floods

Droughts

Droughts are severe when rainfall in an area is below 50% of the average rainfall. When an area receives rainfall that is 25% less than the average rainfall, it is termed as a General Drought. Droughts are divided into three types: Seasonal Drought, Water Drought and Agricultural Drought.

Seasonal Drought occurs when there’s little rain for a prolonged period. Lack of water in water resources such as rivers, lakes and ponds is called a Water Drought and lack of crops is called an Agricultural Drought.

Factors for occurrence of drought:

Scarce rain or no rain at all

Destruction of forests

Over use of agricultural land. Less vegetation also leads to droughts

Depleting ground water level accompanied by the absence of rain

Coping with drought:

Store rain water to prevent droughts. Dig ponds to collect the rain water and build dams to collect excess rain water.

Plant more trees to avoid droughts, around 35% of land should be earmarked as green belts

Regions that receive excess rainfall may share the extra water with the parched and dry regions

Water supply to the agricultural fields in the parched regions can be increased by rainwater harvesting, canal irrigation and building contour bunds

Farmers can insure their crop to prevent financial losses.

Atomic, Biological and Chemical Disasters

Weapons are created by man, so the disasters linked to it are called man-made disasters. Human disasters are man-made and involve elements of human intent, negligence, or the failure of a man-made system.

Atomic disasters are extremely damaging and are mostly caused through weapons of mass destruction. Apart from nuclear bombs, traditional bombs, often used by terrorists, also cause severe destruction.

Government plays important role in making people aware of such disasters like:

Warnings forbidding the people to touch unclaimed substances put up everywhere especially on public transport

In case of an attack, people are advised to stay calm and try to help the wounded

Biological disaster is another type of man-made disaster. Such disasters are caused by microorganisms that cause epidemics and have spread due to man-made conditions. Most of these have been infectious diseases such as malaria, plague, diphtheria, tuberculosis and influenza. These viruses affect birds and animals too.

Chemical disaster is another man-made disaster. Leakages of radioactive material result of human error and result in far reaching damages.

General Human Disasters - 1

Fires disasters are mostly man-made and caused due to negligence and lack of maintenance.

Causes of sire:

Household fires are quite common and are caused mostly of carelessness

Electrical wiring should be checked regularly to prevent house fires caused by short circuits

Defective gas cylinder with leaks may explode on lighting the stove

Military ammunition depots are also prone to accidental fires. Forests are also prone to man-made fires which occur due to the carelessness of man. Fire can occur indoors as well as outdoors.

Fire preventive measures:

Keep inflammable matter at home and a fire extinguisher handy

Remember to switch off all the electrical gadgets and the gas before going outside

Keep match boxes out of reach of children and restrain smoking in the house

For quick getaway in case of fire, ensure that all exits like doors are easily accessible

Call the fire brigade immediately without wasting a single moment

Try to crawl because smoke is always less near the floor

The government has its own share of do’s and don’ts. It contributes to the safety of its people through stringent checks against violation of safety norms.

Disasters Involving Modes of Transport

Human disasters include accidents that occur while traveling by road, rail and air. Speeding, drunk driving and inadequate use of helmets, seat belts and child restraints in vehicles are the main reasons for road accidents in India.

Measure to prevent road accidents:

Follow traffic rules

Legal age to start driving is 18. Start only when you are competent and legally allowed to drive

Strictly follow the rules.

No talking on cell phones while driving, following the speed limit and using helmets when riding bikes.

A number of accidents occur on the highways generally involving trucks. Truck drivers in India need to be educated about traffic rules and the authorities need to be strict about enforcing these. Train accidents are usually caused by derailment, signal failure or fires caused by inflammable material.

Rules to prevent train accidents:

Avoid smoking in trains and never carry an inflammable material

Pay attention to signals, and look out while crossing unmanned level crossings

Air travel has gained popularity in recent years due to the introduction of low cost carriers. Plane accidents occur due to human error as well as extreme climactic conditions. Some human-made air disasters can be caused by poor maintenance of the aircraft, fire outbreaks and tired or inexperienced pilots. There are also eventualities like hijacking.

Rules to prevent air accidents:

On boarding, listen carefully to the instructions given in the plane

Look out for the nearest emergency exits and understand how they work

Disasters involving road, rail and air are usually caused by human errors and can be easily avoided by following rules and regulations.

Stages of Disaster Management

Disaster management prepares us to deal with such situations by preventing any calamity, minimising the effects, and taking timely action for normalising the situation. Disaster Management is a chain of activities carried out before, during and after the disaster occurs.

Disaster management has 4 important stages:

These are advance preparation,

Relief to the victims,

Restoration of normalcy and

Prevention plan for the future.

Role of Administration

On national level, the role of the administration is to initiate rescue and relief operations depending on the gravity of the disaster. At the Central level, the Government has nominated nodal ministries to manage various types of disasters which help in streamlining rescue operations.

The National calamity management committee is controlled by the Cabinet Secretary. The calamity management group also is responsible for disaster management and functions under the Central Aid Commissioner.

Technical support is provided by organizations like the Central Weather Science Department (for cyclone and earthquake), Defence Research and Development Organisation and the Civil Defence General Director.

At the State Level, a committee under the Chief Minister or the Chief Secretary views and takes care of relief operations. At the district level, the District Magistrate and the District Administration are responsible for executing relief operations.

The Block Development Officer manages the operations at the block level in case of any disaster. At the village level, the Sarpanch of a village heads the disaster management committee and assists the various organizations working in the field.

The various institutions involved in disaster management at different levels throughout the country are the United Nations Disaster Management Team (UNDMT), Indian Armed Forces, National Cadet Corps (NCC), Civil Defence, National Service Scheme (NSS), Nehru Youth Centre, Home Guards along with some volunteers from the private sector and media.

To increase awareness among people, a course for disaster management has been introduced in schools, technical colleges, training and higher academic courses. The government passed the National Disaster Management Act (DM Act) in 2005 having a holistic approach to disasters that cover -prevention, mitigation, capacity-building, preparedness, assessment and rehabilitation.