Disaster Management A sudden disturbance that adversely affect the earth, plants or animals is called disaster. Earthquakes, floods, storms are its instances. They harm greatly. Though man has learnt to face the problems coming in his midway but he is helpless before these. There are certain areas which have been exposed to more than one disaster, these kinds of places are known as Multi-hazard zones.
Disasters can be categorised into two categories:
(a) Natural Disasters.
(b) Man-made disasters.
Disasters take place because of certain natural processes or because of the imbalance in nature are called natural disasters like earthquakes, storms etc. These are also known as natural calamity. These are widespread and unpredictable, which cause a great harm to human beings, animals, plants, properties etc. While human made disasters take place because of some mistake done by human beings e.g. accidents, building collapse, dam bursts etc. Man-made disasters often cause less destruction than the natural disasters. Intensity of disasters determine the quantum of damage caused by them.
Nature causes greatest destructions because an earthquake may cause big damage or destruction to man and animals. Cyclone, floods etc are all natural disasters which may cause a great harm to their victims. We may take the following steps in order to avoid the disasters.
(a) Infrastructure should be strengthened.
(b) Human beings should be aware of these disasters.
(c) Some better policies must be initiated at the national and international level as well.
EARTHQUAKES
A sudden trembling or vibration in earth’s crust is called earthquake. The place where an earthquake begins is known as hypocenter. However, it originates in its crust. Place just above the hypocenter, where the intensity of earthquake is maximum is known as epicenter. Millions of earthquakes happen each year but as their intensity remains very low, we are unable to even feel them. But sometimes they are so destructive and powerful that they cause huge harm. Specifically when earthquakes happen at night there is much more destruction because none gets opportunity to escape from it. It damages building, causes death of animals and much more. Earthquakes also lead to some other hazards like landslides, floods, tsunami etc.
The frequency of earthquakes measured on Richter scale’. Its intensity measured by using modified Members scales. divided into four categories of classes whitening the intensity of earthquakes.
These are-(a) class I(III,) (b) class IV(VI,) (c) class VII(X )and (d) class XI(XII). The fourth category of classes XI(XII) causes total devastation in which objects are thrown upwards into air. An earthquake is so sudden and violent that it neither be predicated nor prevented. But scientists are trying to find some ways to predict earthquakes.
Richter scale hit Bhuj town in Gujarat state on 26th January 2001. Here are some major earthquakes occurred in India.
Reasons for the occurrence of an earthquake
The uppermost layer of earth ‘crust’ is made-up of tectonic plates which are interlocked with each other. These rocks keep on floating on a semi liquid rock called ‘mantle’. Sometimes these plates collide due to pressure on them causing faults. This collision creates vibration around the earth causing earthquakes of varying degrees of magnitude. To measure the frequency of earthquakes scientists use seismograph invented by Charles Richter in 1935. It is used to measure the energy released during an earthquake. Seismograph has ranges from 0 to 9. Earthquake also results in the formation of shore areas, bays and gulfs, block mountains, rift valleys, hot spring etc.
Though earthquakes are unpredictable and we can’t stop them. But we can take some precautions to escape from it.
(1) Move to any open place like playground.
(ii) Never stand under the fan, in front of the mirror and window etc.
(iii) We should not use lift.
(iv) Try to protect the head and eyes.
(v) Get out of the car.
(vi) We should apply the proper technology.
