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Natural Disasters: Definition and Types of Natural Disasters
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Natural disasters have been a part of human life since time immemorial. Natural disasters are events that are beyond human control which require swift action. However, human intervention has increased the frequency and intensity of these disasters.
- They create environmental damage, economic and human loss etc.
- It has become extremely difficult to distinguish between natural disasters, man-made disasters and man accelerated disasters as several variables, like development, climate change, play a role.
- There are vulnerable areas that are always susceptible to natural disasters. For example: earthquakes in Japan.
- Creating warning systems and disaster management plans are crucial to mitigating impact of natural disasters
Learn more about Ozone Layer Depletion, here.
What is a Natural Disaster?
A Natural disaster is defined as an adverse event brought about by the natural processes of earth disrupting the normal functioning of society. It causes widespread destruction to the natural environment and leads to loss of life. The occurrence of a natural hazard is a precondition for a natural disaster. In other words, only when natural hazards happen in a vulnerable area does it become a disaster.
Read more about the 10 worst natural disasters here.
Different Types of Natural DisasterGeological disaster
Natural disasters caused by geological processes are called geological disasters. Some causes are shifts in tectonic plates, seismic activity etc. They are also called geophysical disasters. Regions of earth where there is active plate movement are often prone to earthquakes.
Earthquakes- An earthquake is a result of the forces in the earth’s surface or crust. Sudden breaks on the surface can lead to vibration of the ground, damage to buildings and roads etc. They often happen at the joining points of plates, called fault plates. Earthquakes can lead to other natural disasters like landslides and tsunamis also. There are often aftershocks which take a huge toll on the survivors’ mental state. The immediate search and rescue programme is accompanied with efforts to provide food, shelter and medical services.
The magnitude of an earthquake is understood by the Richter Scale. Anything above 6 on the scale has devastating effects. Approximately 100-150 such earthquakes happen every year.
The damage depends on the intensity and epicenter of the earthquake. The 2002 Bhuj earthquake in Gujarat recorded 6.9 on the Richter scale killing over 13000 people.
Read more about earthquakes here.
Avalanches– Avalanche is triggered when a mass of material gets detached from its surroundings and slides down a slope. On the way down, avalanches acquire more strength as more material gets added to it. The different types of avalanches are rock avalanche, ice avalanche and debris avalanche. Snow avalanches are most common in ice clad mountains. Small quantities of snow or sometimes large slabs of ice slide down wreaking enormous havoc. Adventure sports persons and tourists are most likely to get involved in this natural disaster. Rescue operations are most difficult due to the climatic conditions and lack of accessibility.
Know more about Non-Renewable Energy, here.
Landslides– Landslides are similar to avalanches. The material that slides down is usually soil and rock. It can be superficial or deep. It is caused by soil erosion and heavy rains. They are usually associated with severe cyclonic storms, flooding in rivers etc. Human activities like mining, construction of buildings and roads also lead to landslides. Gravity is the major player of a landslide. The western ghats of India are very prone to landslides during the monsoon season.
Volcanic eruptions– The eruption of volcanoes lead to massive outburst of lava to the surrounding areas damaging the flora and fauna. The ash that comes out is very harmful for human beings. The formation of a cloud-like structure made of hot gas and volcanic matter, called the pyroclastic flow, is the most dangerous outcome of a volcanic eruption. It is believed that Pompeii was destroyed by such an eruption. The 1985 Armero tragedy in Colombia destroyed a town completely, killing 23000 people, as the volcano exploded unexpectedly.
Know more about the different types of volcanoes here.
Hydrological Disasters
Hydrological disasters are caused by a sudden change in the quantity or movement in the earth’s water sources.
- Flood- A flood is the overflow of a water body submerging land near its basin. Human changes like construction of dams increase the frequency and severity of floods. Unexpected rainfall and mismanagement of water catchment areas are also a reason. The Brahmaputra river is infamous for its annual flooding creating difficult conditions for life. Recently, urban flooding has also increased due to lack of channels for diverting flood water away from inhabited areas. Cities like Mumbai and Chennai have borne the brunt of such mismanagement.
- Tsunami- A tsunami is caused by a sudden displacement in the quantity of water in a large lake or usually the ocean. Earthquakes and underwater landslides or volcanoes can lead to tsunamis. Tsunami is consisted of subsequent waves that can last for minutes or even hours. They usually affect the coastline destroying the entire built environment and enormous loss of human life. The 2004 tsunami in the Indian Ocean was the deadliest tsunami in the recent decades leading to a loss of over 2 lakh people.
Also read more about Renewable Energy, here.
Meteorological disasters
These are disasters that are caused by meteorological events like thunderstorms, blizzards, hailstorms, cyclones, tornadoes, droughts etc. These are extreme weather conditions that affect the normal functioning of society. They wreak huge economic damage every year. Massive damage to crops and buildings lead to severe humanitarian crises.
You might also be interested in reading more about Environmental Issues in India.
Other Disasters
There are also other kinds of disasters like forest fires which can’t be classified into either of the above categories. Forest fires are unplanned and difficult to control fires occurring due to combustible vegetation. Droughts, warmer weather conditions etc are ideal conditions for forest fires.
Also, read more Man-Made Hazards, here.
Hope this article helped you to understand the basics of natural disasters. If you are looking for interactive preparation for competitive exams, try the Testbook App.
Natural Disasters: FAQs
Define natural disasters?
A Natural disaster is defined as an adverse event brought about by the natural processes of earth disrupting the normal functioning of society.
Which are the different types of natural disasters?
The different types of natural disasters are geological, hydrological, meteorological and other types of natural disaster.
What are the different types of geological natural disasters?
Earthquakes, avalanches, landslides and volcanic eruptions are the different types of geological disasters.
What are tsunamis?
A Tsunami is a sudden displacement in the quantity of water in a large lake or usually the ocean.
Which scale is used to track the intensity of an earthquake?
The Richter scale is used to track the intensity of an earthquake.