Textbook: Disaster Management | Defence Studies Class 10 (Maharashtra SSC Board) PDF Download

 Page 1


15
Disaster Management    
Natural Disasters     Manmade  Disasters
(Earthquake, floods, Landslides,  (Road accidents, Fire, Industrial 
Tsunami, Cyclone Droughts     accidents and Biological hazards)
Precipitation and cloud burst)
Types of Disasters
Internal security also includes aspects like natural and man-made disasters. It brings 
together the Police, Paramilitary and the Armed Forces along with immigration and customs, 
firefighters and the civil society on a single platform to tackle these disasters. 
This chapter focuses on various hazards and disasters that we see happening around us. 
    Hazards and Disasters
Hazards : A Hazard is a phenomenon that has the potential to cause threats to life, 
property, environment and normal processes. Hazards are natural and human induced. 
Earthquakes, Floods, Tsunami Landslides and Droughts are some of the natural hazards. 
Industrial accidents, road accidents and most of the fires are typical examples of Human 
Induced Hazards. 
Natural hazards exist in some specific geographical areas, while human induced 
hazards are due to human errors or failure of some processes and could happen everywhere. 
Hazards may become active suddenly or build up slowly. 
Disasters : Disasters are the occurrences caused due to some hazards that become 
active and go out of control. Thus, they are events that cause substantial damage to property 
and environment and loss or injury to life, creating imbalance in society and disturbing its 
normalcy. It takes tremendous efforts by the entire nation state and the populace to restore 
normalcy.  
Disasters could be sudden or slow in their build-up and occurrence. Ill-effects of 
disasters depend upon the intensity and speed of the occuring hazard that causes disaster. It 
also depends upon the vulnerability of the population and infrastructure. 
    Natural Disasters 
Natural disasters are mostly the ones that cannot be prevented. They cause great 
losses and damages. Earthquakes, Floods, Landslides, Tsunamis, Droughts, Lightning 
Strikes, Cloud Bursts, Heavy Rainfall (precipitation) and Cyclones are some of the most 
commonly experienced natural disasters in India. Every disaster has complex ill-effects. 
They are generally in the form of deaths and injuries to living beings, damage to property and 
infrastructure resulting in economic losses, loss of crops and vegetation, industrial losses and 
even degradation of environment. All these effects lead to disturbance of life and exert great 
social, administrative and economic burdens on the society. Let us study these disasters.
Chapter 3
Page 2


15
Disaster Management    
Natural Disasters     Manmade  Disasters
(Earthquake, floods, Landslides,  (Road accidents, Fire, Industrial 
Tsunami, Cyclone Droughts     accidents and Biological hazards)
Precipitation and cloud burst)
Types of Disasters
Internal security also includes aspects like natural and man-made disasters. It brings 
together the Police, Paramilitary and the Armed Forces along with immigration and customs, 
firefighters and the civil society on a single platform to tackle these disasters. 
This chapter focuses on various hazards and disasters that we see happening around us. 
    Hazards and Disasters
Hazards : A Hazard is a phenomenon that has the potential to cause threats to life, 
property, environment and normal processes. Hazards are natural and human induced. 
Earthquakes, Floods, Tsunami Landslides and Droughts are some of the natural hazards. 
Industrial accidents, road accidents and most of the fires are typical examples of Human 
Induced Hazards. 
Natural hazards exist in some specific geographical areas, while human induced 
hazards are due to human errors or failure of some processes and could happen everywhere. 
Hazards may become active suddenly or build up slowly. 
Disasters : Disasters are the occurrences caused due to some hazards that become 
active and go out of control. Thus, they are events that cause substantial damage to property 
and environment and loss or injury to life, creating imbalance in society and disturbing its 
normalcy. It takes tremendous efforts by the entire nation state and the populace to restore 
normalcy.  
Disasters could be sudden or slow in their build-up and occurrence. Ill-effects of 
disasters depend upon the intensity and speed of the occuring hazard that causes disaster. It 
also depends upon the vulnerability of the population and infrastructure. 
    Natural Disasters 
Natural disasters are mostly the ones that cannot be prevented. They cause great 
losses and damages. Earthquakes, Floods, Landslides, Tsunamis, Droughts, Lightning 
Strikes, Cloud Bursts, Heavy Rainfall (precipitation) and Cyclones are some of the most 
commonly experienced natural disasters in India. Every disaster has complex ill-effects. 
They are generally in the form of deaths and injuries to living beings, damage to property and 
infrastructure resulting in economic losses, loss of crops and vegetation, industrial losses and 
even degradation of environment. All these effects lead to disturbance of life and exert great 
social, administrative and economic burdens on the society. Let us study these disasters.
Chapter 3
16
Earthquakes :
 When an earthquake takes place, it causes building structures to collapse. The 
collapsed buildings cause loss of lives and injuries. There are many secondary effects like 
landslides, dam bursting, snapping of high tension overhead wires, electrocution and even 
fires. Large scale epidemics spread because of decaying of the dead and contamination of 
water. Sometimes, the earth’s surface cracks. Water streams change their courses. There is 
tremendous economic loss and social ill-effects. 
 Earthquakes are a common phenomenon all over the world. Construction technology 
is now evolving to construct earthquake resistant structures. Earthquakes measure from 
intensity 0.1 to 9.9 (10 being hypothetical) on a Richter Scale. 
Earthquake Damage
Richter Scale Effects
1.0   Not felt by humans
3.0   Felt by a few people on the upper stories of tall buildings
3.5   Felt by people lying down on hard surfaces
4.0   Felt indoors by many and by very few outside the buildings
4.5   Generally felt by everyone.
5.0   Trees sway, chandeliers swing, loose objects shift and fall causing damage
6.0   Cracking of walls and plaster falls
6 to 7   Chimneys fall, weak structures collapse
7.0   Some structures collapse, pipes break
7.5   Ground cracks, many buildings collapse, landslides occur
8.0   Most buildings and bridges collapse
Greater than 8  Total destruction, triggers tsunami (if under oceanic surface)
Floods :
 Floods occur in many countries of the world. Almost 65% of India’s main land is 
prone to floods. Floods cause havoc in states like Bihar, UP, Maharashtra, West Bengal, 
North East states and Orissa quite frequently. Floods are of two types – the flowing ones 
and sedentary ones. Flowing ones are because of overflowing rivers and sedentary ones are 
Page 3


15
Disaster Management    
Natural Disasters     Manmade  Disasters
(Earthquake, floods, Landslides,  (Road accidents, Fire, Industrial 
Tsunami, Cyclone Droughts     accidents and Biological hazards)
Precipitation and cloud burst)
Types of Disasters
Internal security also includes aspects like natural and man-made disasters. It brings 
together the Police, Paramilitary and the Armed Forces along with immigration and customs, 
firefighters and the civil society on a single platform to tackle these disasters. 
This chapter focuses on various hazards and disasters that we see happening around us. 
    Hazards and Disasters
Hazards : A Hazard is a phenomenon that has the potential to cause threats to life, 
property, environment and normal processes. Hazards are natural and human induced. 
Earthquakes, Floods, Tsunami Landslides and Droughts are some of the natural hazards. 
Industrial accidents, road accidents and most of the fires are typical examples of Human 
Induced Hazards. 
Natural hazards exist in some specific geographical areas, while human induced 
hazards are due to human errors or failure of some processes and could happen everywhere. 
Hazards may become active suddenly or build up slowly. 
Disasters : Disasters are the occurrences caused due to some hazards that become 
active and go out of control. Thus, they are events that cause substantial damage to property 
and environment and loss or injury to life, creating imbalance in society and disturbing its 
normalcy. It takes tremendous efforts by the entire nation state and the populace to restore 
normalcy.  
Disasters could be sudden or slow in their build-up and occurrence. Ill-effects of 
disasters depend upon the intensity and speed of the occuring hazard that causes disaster. It 
also depends upon the vulnerability of the population and infrastructure. 
    Natural Disasters 
Natural disasters are mostly the ones that cannot be prevented. They cause great 
losses and damages. Earthquakes, Floods, Landslides, Tsunamis, Droughts, Lightning 
Strikes, Cloud Bursts, Heavy Rainfall (precipitation) and Cyclones are some of the most 
commonly experienced natural disasters in India. Every disaster has complex ill-effects. 
They are generally in the form of deaths and injuries to living beings, damage to property and 
infrastructure resulting in economic losses, loss of crops and vegetation, industrial losses and 
even degradation of environment. All these effects lead to disturbance of life and exert great 
social, administrative and economic burdens on the society. Let us study these disasters.
Chapter 3
16
Earthquakes :
 When an earthquake takes place, it causes building structures to collapse. The 
collapsed buildings cause loss of lives and injuries. There are many secondary effects like 
landslides, dam bursting, snapping of high tension overhead wires, electrocution and even 
fires. Large scale epidemics spread because of decaying of the dead and contamination of 
water. Sometimes, the earth’s surface cracks. Water streams change their courses. There is 
tremendous economic loss and social ill-effects. 
 Earthquakes are a common phenomenon all over the world. Construction technology 
is now evolving to construct earthquake resistant structures. Earthquakes measure from 
intensity 0.1 to 9.9 (10 being hypothetical) on a Richter Scale. 
Earthquake Damage
Richter Scale Effects
1.0   Not felt by humans
3.0   Felt by a few people on the upper stories of tall buildings
3.5   Felt by people lying down on hard surfaces
4.0   Felt indoors by many and by very few outside the buildings
4.5   Generally felt by everyone.
5.0   Trees sway, chandeliers swing, loose objects shift and fall causing damage
6.0   Cracking of walls and plaster falls
6 to 7   Chimneys fall, weak structures collapse
7.0   Some structures collapse, pipes break
7.5   Ground cracks, many buildings collapse, landslides occur
8.0   Most buildings and bridges collapse
Greater than 8  Total destruction, triggers tsunami (if under oceanic surface)
Floods :
 Floods occur in many countries of the world. Almost 65% of India’s main land is 
prone to floods. Floods cause havoc in states like Bihar, UP, Maharashtra, West Bengal, 
North East states and Orissa quite frequently. Floods are of two types – the flowing ones 
and sedentary ones. Flowing ones are because of overflowing rivers and sedentary ones are 
17
because the heavy rains cause submergence of low laying areas in urban centres. The rain 
data and monitoring of water levels allows a fair warning period today. This ensures that 
people can be shifted to safer areas and help save their lives.
 Effects of floods are in the form of submergence of areas causing damage to houses 
and properties, spoilage of crops and vegetation and drowning of people and cattle. Further, 
the secondary effects are in the form of displacement of population, Dam Bursts (due to 
water pressure) damage to infrastructure (Bridges, Railway Lines, Power Grids, Mobile 
Towers and many more). Epidemics also get triggered after floods.
Flood Situation
Landslides :
 Landslide is a phenomenon where mud and rocks that form hills and mountains 
come sliding down with great force. This is due to natural causes like heavy rain or human 
intervention done through building of railway lines, digging canals, digging tunnels, mining 
for gravel etc. 
 In 2005, several people lost their lives in Jui village in Raigad District of  
Maharashtra. In 2014, there was a massive landslide in Malin village in Pune district.  
Careful observation allows a fair judgment of a possible landslide so as to plan for 
precautionary measures. 
Landslide in Raigad District - 2005
Page 4


15
Disaster Management    
Natural Disasters     Manmade  Disasters
(Earthquake, floods, Landslides,  (Road accidents, Fire, Industrial 
Tsunami, Cyclone Droughts     accidents and Biological hazards)
Precipitation and cloud burst)
Types of Disasters
Internal security also includes aspects like natural and man-made disasters. It brings 
together the Police, Paramilitary and the Armed Forces along with immigration and customs, 
firefighters and the civil society on a single platform to tackle these disasters. 
This chapter focuses on various hazards and disasters that we see happening around us. 
    Hazards and Disasters
Hazards : A Hazard is a phenomenon that has the potential to cause threats to life, 
property, environment and normal processes. Hazards are natural and human induced. 
Earthquakes, Floods, Tsunami Landslides and Droughts are some of the natural hazards. 
Industrial accidents, road accidents and most of the fires are typical examples of Human 
Induced Hazards. 
Natural hazards exist in some specific geographical areas, while human induced 
hazards are due to human errors or failure of some processes and could happen everywhere. 
Hazards may become active suddenly or build up slowly. 
Disasters : Disasters are the occurrences caused due to some hazards that become 
active and go out of control. Thus, they are events that cause substantial damage to property 
and environment and loss or injury to life, creating imbalance in society and disturbing its 
normalcy. It takes tremendous efforts by the entire nation state and the populace to restore 
normalcy.  
Disasters could be sudden or slow in their build-up and occurrence. Ill-effects of 
disasters depend upon the intensity and speed of the occuring hazard that causes disaster. It 
also depends upon the vulnerability of the population and infrastructure. 
    Natural Disasters 
Natural disasters are mostly the ones that cannot be prevented. They cause great 
losses and damages. Earthquakes, Floods, Landslides, Tsunamis, Droughts, Lightning 
Strikes, Cloud Bursts, Heavy Rainfall (precipitation) and Cyclones are some of the most 
commonly experienced natural disasters in India. Every disaster has complex ill-effects. 
They are generally in the form of deaths and injuries to living beings, damage to property and 
infrastructure resulting in economic losses, loss of crops and vegetation, industrial losses and 
even degradation of environment. All these effects lead to disturbance of life and exert great 
social, administrative and economic burdens on the society. Let us study these disasters.
Chapter 3
16
Earthquakes :
 When an earthquake takes place, it causes building structures to collapse. The 
collapsed buildings cause loss of lives and injuries. There are many secondary effects like 
landslides, dam bursting, snapping of high tension overhead wires, electrocution and even 
fires. Large scale epidemics spread because of decaying of the dead and contamination of 
water. Sometimes, the earth’s surface cracks. Water streams change their courses. There is 
tremendous economic loss and social ill-effects. 
 Earthquakes are a common phenomenon all over the world. Construction technology 
is now evolving to construct earthquake resistant structures. Earthquakes measure from 
intensity 0.1 to 9.9 (10 being hypothetical) on a Richter Scale. 
Earthquake Damage
Richter Scale Effects
1.0   Not felt by humans
3.0   Felt by a few people on the upper stories of tall buildings
3.5   Felt by people lying down on hard surfaces
4.0   Felt indoors by many and by very few outside the buildings
4.5   Generally felt by everyone.
5.0   Trees sway, chandeliers swing, loose objects shift and fall causing damage
6.0   Cracking of walls and plaster falls
6 to 7   Chimneys fall, weak structures collapse
7.0   Some structures collapse, pipes break
7.5   Ground cracks, many buildings collapse, landslides occur
8.0   Most buildings and bridges collapse
Greater than 8  Total destruction, triggers tsunami (if under oceanic surface)
Floods :
 Floods occur in many countries of the world. Almost 65% of India’s main land is 
prone to floods. Floods cause havoc in states like Bihar, UP, Maharashtra, West Bengal, 
North East states and Orissa quite frequently. Floods are of two types – the flowing ones 
and sedentary ones. Flowing ones are because of overflowing rivers and sedentary ones are 
17
because the heavy rains cause submergence of low laying areas in urban centres. The rain 
data and monitoring of water levels allows a fair warning period today. This ensures that 
people can be shifted to safer areas and help save their lives.
 Effects of floods are in the form of submergence of areas causing damage to houses 
and properties, spoilage of crops and vegetation and drowning of people and cattle. Further, 
the secondary effects are in the form of displacement of population, Dam Bursts (due to 
water pressure) damage to infrastructure (Bridges, Railway Lines, Power Grids, Mobile 
Towers and many more). Epidemics also get triggered after floods.
Flood Situation
Landslides :
 Landslide is a phenomenon where mud and rocks that form hills and mountains 
come sliding down with great force. This is due to natural causes like heavy rain or human 
intervention done through building of railway lines, digging canals, digging tunnels, mining 
for gravel etc. 
 In 2005, several people lost their lives in Jui village in Raigad District of  
Maharashtra. In 2014, there was a massive landslide in Malin village in Pune district.  
Careful observation allows a fair judgment of a possible landslide so as to plan for 
precautionary measures. 
Landslide in Raigad District - 2005
18
Landslide at Malin Village in Pune District - 2014
Tsunami :
 Tsunami is a Japanese word that means “Giant Wave”. This is caused by a strong 
earthquake or a volcanic eruption that occurs below the ocean waters (crust below the ocean 
waters). In India, Tsunami struck the coastal regions in December 2004. In March 2011, 
Japan suffered great losses due to Tsunami that had followed a massive Earthquake. Tsunami 
waves are known to be as high as 30 mtr (height of a 10 storey building approximately!). 
Tsunami warning systems are now available in the world. Tsunami waves travel nearly 
upto 1 km inland. It can submerge the coastal belt, destroy houses and infrastructure and 
kill people because of drowning and collapsing of infrastructure. The secondary effects are 
disruption of communications, spread of epidemics and loss of coastal crops. 
A Picture Showing Tsunami Wave 
Page 5


15
Disaster Management    
Natural Disasters     Manmade  Disasters
(Earthquake, floods, Landslides,  (Road accidents, Fire, Industrial 
Tsunami, Cyclone Droughts     accidents and Biological hazards)
Precipitation and cloud burst)
Types of Disasters
Internal security also includes aspects like natural and man-made disasters. It brings 
together the Police, Paramilitary and the Armed Forces along with immigration and customs, 
firefighters and the civil society on a single platform to tackle these disasters. 
This chapter focuses on various hazards and disasters that we see happening around us. 
    Hazards and Disasters
Hazards : A Hazard is a phenomenon that has the potential to cause threats to life, 
property, environment and normal processes. Hazards are natural and human induced. 
Earthquakes, Floods, Tsunami Landslides and Droughts are some of the natural hazards. 
Industrial accidents, road accidents and most of the fires are typical examples of Human 
Induced Hazards. 
Natural hazards exist in some specific geographical areas, while human induced 
hazards are due to human errors or failure of some processes and could happen everywhere. 
Hazards may become active suddenly or build up slowly. 
Disasters : Disasters are the occurrences caused due to some hazards that become 
active and go out of control. Thus, they are events that cause substantial damage to property 
and environment and loss or injury to life, creating imbalance in society and disturbing its 
normalcy. It takes tremendous efforts by the entire nation state and the populace to restore 
normalcy.  
Disasters could be sudden or slow in their build-up and occurrence. Ill-effects of 
disasters depend upon the intensity and speed of the occuring hazard that causes disaster. It 
also depends upon the vulnerability of the population and infrastructure. 
    Natural Disasters 
Natural disasters are mostly the ones that cannot be prevented. They cause great 
losses and damages. Earthquakes, Floods, Landslides, Tsunamis, Droughts, Lightning 
Strikes, Cloud Bursts, Heavy Rainfall (precipitation) and Cyclones are some of the most 
commonly experienced natural disasters in India. Every disaster has complex ill-effects. 
They are generally in the form of deaths and injuries to living beings, damage to property and 
infrastructure resulting in economic losses, loss of crops and vegetation, industrial losses and 
even degradation of environment. All these effects lead to disturbance of life and exert great 
social, administrative and economic burdens on the society. Let us study these disasters.
Chapter 3
16
Earthquakes :
 When an earthquake takes place, it causes building structures to collapse. The 
collapsed buildings cause loss of lives and injuries. There are many secondary effects like 
landslides, dam bursting, snapping of high tension overhead wires, electrocution and even 
fires. Large scale epidemics spread because of decaying of the dead and contamination of 
water. Sometimes, the earth’s surface cracks. Water streams change their courses. There is 
tremendous economic loss and social ill-effects. 
 Earthquakes are a common phenomenon all over the world. Construction technology 
is now evolving to construct earthquake resistant structures. Earthquakes measure from 
intensity 0.1 to 9.9 (10 being hypothetical) on a Richter Scale. 
Earthquake Damage
Richter Scale Effects
1.0   Not felt by humans
3.0   Felt by a few people on the upper stories of tall buildings
3.5   Felt by people lying down on hard surfaces
4.0   Felt indoors by many and by very few outside the buildings
4.5   Generally felt by everyone.
5.0   Trees sway, chandeliers swing, loose objects shift and fall causing damage
6.0   Cracking of walls and plaster falls
6 to 7   Chimneys fall, weak structures collapse
7.0   Some structures collapse, pipes break
7.5   Ground cracks, many buildings collapse, landslides occur
8.0   Most buildings and bridges collapse
Greater than 8  Total destruction, triggers tsunami (if under oceanic surface)
Floods :
 Floods occur in many countries of the world. Almost 65% of India’s main land is 
prone to floods. Floods cause havoc in states like Bihar, UP, Maharashtra, West Bengal, 
North East states and Orissa quite frequently. Floods are of two types – the flowing ones 
and sedentary ones. Flowing ones are because of overflowing rivers and sedentary ones are 
17
because the heavy rains cause submergence of low laying areas in urban centres. The rain 
data and monitoring of water levels allows a fair warning period today. This ensures that 
people can be shifted to safer areas and help save their lives.
 Effects of floods are in the form of submergence of areas causing damage to houses 
and properties, spoilage of crops and vegetation and drowning of people and cattle. Further, 
the secondary effects are in the form of displacement of population, Dam Bursts (due to 
water pressure) damage to infrastructure (Bridges, Railway Lines, Power Grids, Mobile 
Towers and many more). Epidemics also get triggered after floods.
Flood Situation
Landslides :
 Landslide is a phenomenon where mud and rocks that form hills and mountains 
come sliding down with great force. This is due to natural causes like heavy rain or human 
intervention done through building of railway lines, digging canals, digging tunnels, mining 
for gravel etc. 
 In 2005, several people lost their lives in Jui village in Raigad District of  
Maharashtra. In 2014, there was a massive landslide in Malin village in Pune district.  
Careful observation allows a fair judgment of a possible landslide so as to plan for 
precautionary measures. 
Landslide in Raigad District - 2005
18
Landslide at Malin Village in Pune District - 2014
Tsunami :
 Tsunami is a Japanese word that means “Giant Wave”. This is caused by a strong 
earthquake or a volcanic eruption that occurs below the ocean waters (crust below the ocean 
waters). In India, Tsunami struck the coastal regions in December 2004. In March 2011, 
Japan suffered great losses due to Tsunami that had followed a massive Earthquake. Tsunami 
waves are known to be as high as 30 mtr (height of a 10 storey building approximately!). 
Tsunami warning systems are now available in the world. Tsunami waves travel nearly 
upto 1 km inland. It can submerge the coastal belt, destroy houses and infrastructure and 
kill people because of drowning and collapsing of infrastructure. The secondary effects are 
disruption of communications, spread of epidemics and loss of coastal crops. 
A Picture Showing Tsunami Wave 
19
Cyclones :
 Cyclones are climatic hazards. Cyclones originate on land masses as well as oceanic 
water surfaces. The latter ones are more frequent and violent. Cyclones damage houses, 
infrastructure, uproot trees and electric poles, break overhead cables cutting lines of 
communication. Cyclones are accompanied by rain in the coastal areas. 
 India’s East Coast experiences cyclones quite often. Cyclonic winds are known to 
travel at speeds greater than 200 km per hour. The nucleus may be of high pressure or low 
pressure around which the surrounding air spins. The cyclones may spin clockwise or anti-
clockwise and may be termed as cyclones and anti-cyclones. Weather satellites do give us 
warnings of building up of a cyclone and its movement pattern. 
 Cyclone  Destruction During Orissa’s Super Cyclone in 1999
Droughts, Heavy Precipitation and Cloud Bursts :
 While Heavy Precipitation and Cloud Bursts are sudden and more local in their 
geographical expanse, the droughts are slow in becoming effective and cover vast tracts 
of land mass. Warning of Cloud Bursts and precipitation is now available through weather 
radars. Drought conditions depend upon rainfall and ground water levels. These can be 
predicted on the basis rainfall data and measurement of water tables. 
    Man-made Disasters 
Road Accidents :
 Road accidents are a common phenomenon in India. Most of the road accidents are 
attributed to the lack of road discipline. Reasons of road accidents are – rash driving, not 
following the traffic rules (like jumping the ‘Red Signal’, drunken driving and not maintaining 
driving norm.) Many accidents occur because of bad road and weather conditions. Pedestrians 
crossing the roads without due precaution is also a major reason. Unauthorized encroachments 
of the roads by hawkers and faulty parking of vehicles reduces space available to the traffic 
and increases road densities. Vehicle maintenance is also a major cause. After an accident, 
deaths and injuries occur because of non-usage of helmets by two wheeled riders or non-use 
of the seat belts by the occupants of the four-wheeled vehicles.