Samacheer Class 7 Social Science - Natural Hazards

disaster
2. Activities taken during a disaster is called …………………
Response
3. Displacement of water can produce one or more huge destructive waves known as
Tsunami4. In case of fire accidents call the nearby police station or the no ……………….. for the fire service.
101
5. Disaster management refers to ……………….. of lives and property during a natural or manmade disaster.
conservation

dangerous phenomenon
2. A ………………….. (or) trembling of the earth crust is called as earthquake.
sudden movement
3. Due to a strong earthquake, loss of lives, buildings, roads, bridges, and dams are damaged are called …………………..
Hazards
4. ………………….. is a natural hazard. It develops at sea.
Hurricane
5. ………………….. means harbor waves.
Tsunami6. The term………….. is a sudden rush of a crowd of people.
stampede
7. ………………….. is a disaster.
Fire
8. ………………….. refers to the “real-time event of a hazard occurrence and affecting elements at risk.
Disaster Impact
9. ………………….. embraces all measures taken to reduce both the effects of the hazard itself and the vulnerable conditions.
Mitigation
10. If any ………………….. occur dial, 101 for Fire service and 108 for the Ambulance.
emergency medical help

A
B
1. Earthquake
b) Creak / Fault
2. Cyclone
d) Eye of the storm
3. Tsunami
a) Gigantic waves
4. Industrial accident
e) Carelessness
5. Drought
c) Uneven rainfall

A
B
1. Man-made disaster
c) Warfare
2. Industrial disaster
d) Bhopal gas leakage
3. CSIR
e) Laboratories
4. National Disaster Management Authority
a) NDMA
5. Tamilnadu State Disaster Response Force
b) SDRF

Generally, a hazard is a dangerous phenomenon, substance, human activity, or condition that may cause loss of life, injury, health impacts, property damage, loss of livelihoods, services, social and economic disruption or environmental damage.

Tamil Nadu State Disaster Response Force (SDRF) has been constituted with a strength of 80 Police Personnel.
They have been trained in disaster management and rescue operations in consultation with the National Disaster Response Force(NDRF).

Flood :
Heavy rainfall, cyclone, melting of snow, Tsunami or a dam burst.
A large amount of water is burst out.
Displacement of people, Spread of contagious diseases such as Cholera and Malaria, etc.
Cyclone :
Heavy rainfall, cyclone, melting of snow, Tsunami or a dam burst.
When it reaches land and destroys buildings and kills people, it can be described as a disaster.
Disrupts transportation, power communication.

The six disaster management phases that have been used in the concept of disaster cycle are as follows;
Pre-Disaster phase:
Prevention and Mitigation:
The term prevention is often used to embrace the wide diversity of measures to protect persons and property.
Mitigation embraces all measures taken to reduce both the effects of the hazard itself and the vulnerable conditions to it in order to reduce the scale of a future disaster.
Therefore, mitigation may incorporate addressing issues such as land ownership, tenancy rights, wealth distribution, implementation of earthquake-resistant building codes, etc.
Preparedness:
The process includes various measures that enable governments, communities and individuals to respond rapidly to disaster situations to cope with them effectively.
Preparedness includes for example, the formulation of viable emergency plans, the development of warning systems, the maintenance of inventories, public awareness and education and the training of personnel.
Early Warning:
This is the process of monitoring the situation in communities or areas known to be vulnerable to slow onset hazards, and passing the knowledge of the pending hazard to people harmless way.
To be effective, warnings must be related to mass education and training of the population who know what actions they must take when warned.
The Disaster Impact:
This refers to the “real-time event of a hazard occurrence and affecting elements at risk.
The duration of the event will depend on the type of threat; ground shaking may only occur in a matter of seconds during an earthquake while flooding may take place over a longer sustained period.
During Disaster Phase:
Response: This refers to the first stage of response to any calamity, which includes examples such as setting up control rooms, putting the contingency plan in action, issue warning, action for evacuation, taking people to safer areas, rendering medical aid to the needy, etc., simultaneously rendering relief to the homeless, food, drinking water, clothing, etc. to the needy, restoration of communication, disbursement of assistance in cash or kind.
The Post- Disaster Phase:
Recovery: Recovery is used to describe the activities that encompass the three overlapping phases of emergency relief, rehabilitation, and reconstruction.
Rehabilitation: Rehabilitation includes the provision of temporary public utilities and housing as interim measures to assist long-term recovery.
Reconstruction: Reconstruction attempts to return communities with improved pre-disaster functioning. It includes the replacement of buildings; infrastructure and lifeline facilities so that long-term development prospects are enhanced rather than reproducing the same conditions, which made an area or population vulnerable in the first place.
Development: In an evolving economy, the development process is an ongoing activity. Long-term prevention/disaster reduction measures. For example like the construction of embankments against flooding, irrigation facilities as drought-proofing measures, increasing plant cover to reduce the occurrences of landslides, etc.

Flood: Sudden overflow of water in a large amount caused due to heavy rainfall, cyclone, melting of snow, Tsunami or a dam burst.
Effects:
Loss of life and property
Displacement of people and
Spread of contagious diseases such as cholera and Malaria etc.,
Mitigation for a flood:
They include flood walls/sea walls, flood gates, levees, and evacuation routes. Nonstructural measures reduce damage by removing people and property out of risk areas. They induce elevated structures, property buyouts, permanent relocation, zoning, subdivision and building codes.

General Survival Techniques:
During the earthquake be under the table, chair, kneel to the floor and protect yourself. Go near a sturdy wall, sit on the floor and hold the floor strongly and protect yourself. Use only torch lights,
During flood forecast, store up necessary things like first aid etc. Listen to the local Radio/TV for instructions. Cut off all the electrical supplies during flood and earthquake,
In case of fire accidents call fire service (No. 101)
If clothes are on fire, “Don’t Run; Stop, Drop and Roll,”
Stay alert. Trains can come from either direction at any time,
Never sit on the edge of the Station Platform,
Cross the tracks safely.

Earthquake:
A sudden movement (or) trembling of the earth’s crust is called an earthquake. The movement of the tectonic plates, mass wasting, landslides, surface fault, etc., causes earthquakes.
Effects:
Due to a strong earthquake, loss of lives, buildings, roads, bridges, and dams are damaged. Earthquakes cause floods, tsunamis, landslides, fires, breakdown of water supply, and electrical lines. It may change the course of a river too.
Mitigation steps:
Construct an Earthquake resistant building.
Seek shelter under stable tables.
Move to open areas.
Secure your belonging.
Put latches on cabinet doors and file cabinets.
Store hazardous materials in a sturdy place.
Keep fire extinguishers.

To prevent loss of life.
To Protect our belongings.
To create awareness among youngsters.
To be prepared with emergency phone nos.
To be stocked with food, water medicine.
For children and old age people.

Tamil Nadu, Kerala, and Maharastra (Western ghats and Konkan hills)
North Eastern Himalayas – (Darjeeling, and Sikkim)
North West Himalayas – (Uttarakhand, Himachal Pradesh)
Jammu and Kashmir.
7th Social Science Guide Natural Hazards – Understanding of Disaster Management in Practice Additional Important Questions and Answers

During the earthquake be under the table.
Hold the floor strongly.
During flood forecast, store up necessary things like first aid.
In case of fire accidents dial 101 for fire service.
Road accidents can be avoided by following Road safety rules.
Read the safety briefing card available in the seat pocket carefully.