1

TOPIC – NATURAL DISASTERS AND MITIGATION

CLASS – VIII

A disaster (from Greek meaning, “bad star”) is a natural or man-made event that negatively affects life, property, livelihood or industry often resulting in permanent changes to human societies, ecosystems and environment.

What is a Disaster?

2

Effects of Disasters

Both natural and man made disasters result in -

property damage

loss of life

the creation of displaced persons or refugees needing assistance with (a) safety (b) housing (c) nutrition (d) health.

Mitigation is the effort to reduce loss of life and property by lessening the impact of disasters. Mitigation is taking action now—before the next disaster—to reduce human and financial consequences later (analyzing risk, reducing risk, insuring against risk). Effective mitigation requires that we all understand local risks, address the hard choices, and invest in long-term community well-being. Without mitigation actions, we jeopardize our safety, financial security, and self-reliance.

What is Mitigation?

3

Meteorological phenomena such as typhoons and hurricanes, sheet flooding and marine and river based floods;

Geological process such as volcanic eruptions, earthquakes and tsunami; and

Climatic phenomenon such as the El Nino Southern Oscillation that results in a lowering of mean sea level in the east of the region, failure of the monsoon rains in India, and drought in Indonesia and Australia.

Facts to Remember

There has been growing recognition of the significance of disaster ‘prevention and mitigation in the region. Initiatives have already been taken in many countries to address the issue through comprehensive framework of institutions, plans, programmes and legislation. Japan, for example, has constituted a high level committee under the chairmanship of the prime minister to oversee activities related to natural disasters. Over the years, the Government has developed a very efficient framework of organization to reduce the effects of natural disasters.

Were floods in the city of Chennai a result of negligence or was it unavoidable?

Were the stampedes in crowds due to poor crowd management or was it despite all the measures taken?

Causes of Disasters

Rapid population growth is accelerating vulnerability to disasters as settlements encroach into disaster-prone lands. This will ultimately cause more risk to human life in the years to come.

It has been estimated that annual floods losses in some countries are 40 times more today than they were in the 1950s.

According to the Indian Government, one out of every 20 people in the nation is vulnerable to flooding.

In China over 85 percent of the population is concentrated on alluvial plains or basins along river courses which comprise one third of the total land area.

Brain Teasers

4

Was Bhopal tragedy, the leak of methyl Isocynate gas, the result of poor decision or was it the result of circumstances beyond human control?

Were starvation deaths due to drought or were they due to poor distribution of basic needs?

Is water shortage caused by poor rains or is it due to poor management of the water that we receive?

It is an alarming fact that the frequency of disasters of all categories, from epidemics to road accidents and perennial droughts and floods, is escalating. This is causing a manifold growth of injuries, disabilities, diseases, and deaths, disrupting life-supporting systems, and adding to the health, social and economic burden of already impoverished people.

Facts to Remember

Areas where certain disasters are repeated

The area around the Ganga has floods periodically in Bihar.

Certain areas are prone to earthquakes since they are located on or around geological fault lines.

Certain areas are prone to drought.

Forest fires occur in some parts of the world and occur during the hottest periods of the year.

In coastal areas in the East Coast of India we frequently have cyclones.

In India, between 1988 and 1997, disasters killed 5,116 people and affected 24.79 million every year.

In 1998 alone 9,846 people died and 34.11 million people were affected by disasters.

In 2004, the numbers have been vast due to the unprecedented Tsunami.

5

On an average, a powerful earthquake occurs less than once in every two years. At least 40 moderate earthquakes cause damage somewhere in the world each year. Scientists estimate that more than 8,000 minor earthquakes occur each day without causing any damage. Of those, only about 1,100 are strong enough to be felt.

STRUCTURAL HAZARDS

Structures collapse during a quake when they are too weak or rigid to resist strong, rocking forces. In addition, tall buildings may vibrate wildly during an earthquake and knock into each other.

EARTHQUAKE

6

After an earthquake

Loss of power communication, and transportation.

Hamper rescue teams and ambulances, increasing deaths and injuries.

Business and government offices may lose records and supplies. slowing recovery from the disaster.

Many techniques exist for building earthquake-resistant structures. These range from extremely simple to complex. For small to medium-sized buildings, the simpler reinforcement techniques include bolting buildings to their foundations and providing support walls called shear walls. Shear walls, made of reinforced concrete (Concrete with steel rods or bars embedded in it), help strengthen the structure and help resist rocking forces.

Cause

When water overflows the river banks due to high precipitation in the catchments areas, floods are said to occur.

Effects of Flood

Standing crops are destroyed.

Cattle and people are washed away. Damage to electricity, communication, transport and infrastructure.

Homes are washed away or destroyed and household goods are spoilt and becomeunusable.

Floods cause soil erosion and destroy habitat.

After floods pass, due to contamination of water sources, water borne diseases are in evidence.

MITIGATION AND MANAGEMENT OF FLOODS

Since floods occur only in the rainy season, it has been thought that storing the water behind dams would protect the downstream areas from flooding. However, on many occasions, the storage areas over flow and water has to be let out through the sluices. This problem also affects large tanks, Overflowing is more dangerous for tanks than opening a few sluice gates and during overflow the earthen embankments get eroded and the tanks require extensive repair to store water. While the storage of the floodwater is a good idea in principle, it involves allowing for

FLOOD

7

submergence of good forest land and agricultural land to start with and enormous displacement of people and communities.

Flood damage also occurs due to construction of homes in low lying areas such as tank beds. Such construction happens during years of poor rainfall and due to pressure on land. However, in a year of copious rains these areas get flooded and also receive flood waters from other far away sources.

Cyclones occur in coastal areas with winds from the sea and rain lashing the coastal areas. Traditional homes of coastal fisher folk and other residences are often affected and, in many cases, destroyed. 1977 saw the worst cyclone in Indian history. Boats were beached a few kilometers inlands by the winds. With enormous rain from the cyclone, there can be flooding of the coastal areas. The winds can reach upto200km per hour and can uproot trees, electrical posts and blow away roofs. Destruction to property takes place and results in loss of life. Coastal habitats are affected.

CYCLONES

8

Developmental causes

No section on man-made disasters can begin without reference to the disasters that have occurred and are occurring in the name of development. Some of the disasters categories are:

Construction of large dams: These have resulted in flooding of storage area, destruction of forests, habitat and large scale displacement of human beings often involving whole villages and forest communities.

Large scale sand mining: While sand is needed for construction activity, the scale and extent to which it has been used sometimes has affected whole rivers, lowered the water table and caused enormous difficulty to agriculture over vast areas.

Large scale use of forest land for developmental and industrial projects: Huge tracts of forest land have been denotified and used for various public projects with an heavy environmental cost.

Breaking up of continuous forests into isolated patches: This one aspect has caused enormous impact on the migration of elephants and in the long run , will cause the inbreeding of endangered species.

Industrial Causes

Chief among the man-made disasters, after deforestation and construction of large dams, are the industrial effects and accidents. Accidents such as the Bhopal tragedy attract our attention when loss of life and injury occurs on a large scale. However, there are many matters connected with industrial activity – effluent disposal, air pollution, soil pollution – that are causing only small damage now. These could be called ‘disasters waiting to happen’. Small things can escalate out of hand, particularly, in the area of hazardous waste and nuclear operations. The effects would be tragic and dramatic and would get noticed.

Industrial pollution can be called a man-made disaster. When the Bhopal accident occurred in 1984 with over 2000 dead and 200,000 injured, it showed the vulnerability of large populations to the decisions and carelessness of a few.

Similar pollution of ground water, waterways and soil is happening on a continuous basis around the world and in India. These are disasters waiting to happen.

Nuclear establishments that generate radioactive materials are known for potentially dramatic accidents. Chernobyl and Three Mile Island accident bear testimony.

MAN-MADE DISASTERS

9

There are only ancient time-tested ways of averting such disasters:

I. Answer the following briefly:

a) What is a disaster?

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

b) What is mitigation?

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

c) How does disasters affect human life?

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

d) How can cyclone’s affect be avoided?

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

e) People who come to the beach leave it dirty when they go. A small group of college

students volunteer to clean the beaches in order to safeguard the environment. What

values do these volunteers endorse?

A caring approach to the little things we do

Not doing something that is harmful just because no one is looking

Listening to questions from doubters with patience and incorporating their concerns

Refusing to be corrupt.

10

_____________________________________________________________________

______________________________________________________________________

______________________________________________________________________

II. Fill in the blanks:

a) Industrial pollutants can be called _____________________

b) Sometimes it is difficult to differentiate between __________and ___________disasters.

c) In 1998, _______________ million people were affected by disasters.

d) Cyclones are _______________ as they occur annually.

III. Match the following:

(i) El Nino (a) predictable

(ii) Cyclone (b) Methyl Isocynate Gas

(iii) Bhopal Gas Tragedy (c) a natural disasters

(iv) Starvation Death (d) stampede in crowd

(v) Man made disaster (e) Tsunami

(vi) Under sea earthquake (f) drought