Classification and Types of Disasters and Natural Hazards| Class 11

Understanding the different classifications and types of natural hazards and disasters is essential for studying geography. These phenomena cover a broad spectrum of occurrences, including atmospheric disturbances like hurricanes and floods as well as geological upheavals like earthquakes and volcanic eruptions. Examining these divisions sheds light on the dynamic interactions that shape our world and helps develop mitigation and preparedness plans for disasters.

Classification and Types of Disasters and Natural Hazards| Class 11

What is a Natural Hazard?

Conditions found in the natural world that have the potential to endanger persons, property, or both are known as natural hazards. These could be sudden or enduring elements of the corresponding environmental settings, such as ocean currents, the Himalayas’ steep slopes, fragile structural characteristics, or the harsh weather in deserts or glaciated regions.

Classifications of Natural Disaster

There are four different types of classifications of natural disaster

1. Atmospheric Classification
2. Terrestrial Classification
3. Aquatic Classification
4. Biological Classification

1. Atmospheric Classification

Earth’s atmosphere is the primary location for natural disasters, which are the focus of atmospheric classification. These catastrophes are caused by conditions and atmospheric circumstances.

Examples of Atmospheric Classification

Atmospheric Disasters	Examples
Storms	Thunderstorms, Hailstorms, Blizzards
Tropical Cyclones	Hurricanes, Typhoons, Cyclones
Tornadoes	Violent tornadoes, Twisters
Droughts	Prolonged dry spells, Water scarcity
Extreme Temperature	Events Heat Waves, Cold Waves, Frost Events

2. Terrestrial Classification

Natural catastrophes that affect land surfaces, such as geological and geomorphological hazards, are the main emphasis of the terrestrial classification.

Examples of Terrestrial Classification

Terrestrial Disasters	Examples
Earthquakes	Seismic Events, Tremors
Volcanic Eruptions	Lava Flows, Ashfall, Pyroclastic Flows
Landslides	Rockfalls, Mudslides, Debris Flows
Avalanches	Snow Avalanches, Ice Avalanches
Soil Erosion	Wind Erosion, Water Erosion

3. Aquatic Classification

Natural catastrophes that happen in bodies of water, such as lakes, rivers, seas, oceans, and groundwater, are the focus of the aquatic classification.

Examples of Aquatic Classification

Aquatic Disasters	Examples
Floods	Flash Floods, River Flooding, Coastal Flooding
Tidal Waves (Tsunamis)	Seismic Tsunamis, Landslide Tsunamis
Ocean Currents	Gulf Stream, Kuroshio Current
Storm	Surge Coastal Storm Surges, Seawater Inundation

4. Biological Classification

Natural catastrophes that affect living things and ecological systems are categorized as biological classification.

Examples of Biological Classification

Biological Disasters	Examples
Plants and Animals as Colonisers	Ecological Succession, Pioneer Species
Insects Infestation	Locust Swarms, Bark Beetle Outbreaks
Fungal, Bacterial, and Viral Diseases	Bird Flu Outbreaks, Dengue Fever Epidemics

Types of Natural Disaster

Natural disasters happen suddenly and often result in large-scale fatalities, loss of life, and property and disruption of lives and societal structures over which people have little or no control. Therefore, any occurrence that causes a great deal of devastation and damage qualifies as a disaster.

The types of Natural Disaster are given below

1. Earthquake
2. Tsunamis
3. Floods
4. Droughts
5. Landslide

1. Earthquake

• Tectonic Action is what causes earthquakes, which are the most devastating and unpredictable natural disasters.
• Historical earthquake data and scientific evaluations have led to the division of India into five seismic zones.
• Seismic Zone V is the most susceptible, with magnitudes greater than 7.0 registering the biggest earthquakes.
• Earthquakes destroy infrastructure and generate terror, especially in places with a high population density.
• Economic hardship, fatalities, and displacement are examples of socio-environmental effects.
• Settlement disruption, landslides, and cracks are examples of ground effects.
• During earthquakes, man-made structures can crack, slide, or collapse.
• Earthquakes can cause tsunamis, strong waves, and changes in hydrodynamic pressure in bodies of water.
• Earthquake monitoring, vulnerability mapping, and encouraging earthquake-resistant building are the main focuses of mitigation efforts.
• The ‘India Quake’ app and international cooperation are examples of initiatives that support disaster preparedness and response.

2. Tsunamis

• Harmful movements of the seafloor brought on by earthquakes and volcanic eruptions are the cause of tsunamis, sometimes referred to as harbour waves or seismic sea waves.
• To restore water levels, tsunamis first produce a single vertical wave, which is then followed by a succession of afterwaves that oscillate between high crest and low dip.
• Wave height in shallow water and decreased wave speed near coastlines cause tsunamis to have a bigger impact. Wave speed changes with water depth.
• Because of their long wavelengths and small wave height, tsunamis have little effect on ships at sea, which makes identification difficult in deep sea areas.
• Tsunamis frequently strike the coastlines of Alaska, Japan, the Philippines, Southeast Asia, Indonesia, Malaysia, Myanmar, Sri Lanka, and India in the Pacific Ring of Fire.
• When tsunamis hit the coast, their built-up energy is released, resulting in a violent surge of water that obliterates towns, cities, buildings, and communities.
• Compared to other natural dangers, coastal areas, which are highly populated and hubs of human activity, carry a larger risk of property and human life loss.
• Because of the extent of the devastation, mitigating tsunami dangers is difficult and requires worldwide cooperation for efficient disaster management.
• The tsunami that struck on December 26, 2004, took over 300,000 lives and brought attention to the need for international cooperation. As a result, the International Tsunami Warning System was created.
• India’s involvement in global initiatives, including becoming a member of the International Tsunami Warning System following the 2004 tragedy, highlights the significance of teamwork in reducing the likelihood of tsunamis.

3. Floods

• Floods are caused by water overflowing channels during rainy seasons, submerging land and populated areas.
•  40 million hectares of flood-prone land in India were recognised by Rashtriya Barh Ayog, with West Bengal, Bihar, and Assam being the most impacted states.
• While provinces like Rajasthan, Gujarat, Haryana, and Punjab suffer flash floods as a result of human activity and monsoon patterns, northern states like Punjab and Uttar Pradesh also occasionally experience flooding.
• The retreating monsoon may cause flooding in Tamil Nadu in November through January.
• Floods have detrimental effects on human settlements, infrastructure, and agriculture. They destroy crops, roads, bridges, and human settlements, uproot millions of people, and spread illness.
• But floods also leave behind rich silt that is good for crops. Majuli, Assam’s paddy crops benefit from the yearly floods in the Brahmaputra.
• In order to combat flooding, the government builds dams, afforestation, and flood protection embankments in flood-prone areas. It also forbids building in the higher reaches of rivers and clears out human encroachment from floodplains and river channels.
• Storm surge-affected coastal regions receive aid from cyclone centres.

4. Droughts

• Drought Definition: A prolonged period characterized by water scarcity resulting from insufficient precipitation, high evaporation, and excessive water use.
• Complexity: Involves meteorological, agricultural, hydrological, and ecological factors that impact precipitation, soil moisture, groundwater, and social-economic practices.
• Types:

1. Meteorological: Extended periods with little to no rainfall and uneven distribution.
2. Agricultural: Low soil moisture leading to crop failures and affecting rain-fed agriculture.
3. Hydrological: Insufficient water in reservoirs, aquifers, and lakes.
4. Ecological: Decreased productivity in natural ecosystems due to water scarcity.

• Drought Prone Areas in India: – Extreme: Rajasthan, Gujarat’s

5. Landslide

• Rapidly sliding massive bedrock masses cause landslides, which seriously affect the country’s economy and environment. They also cause disruptions to the roads leading to Srinagar and the Konkan Railway tracks.
• Landslides, in contrast to unexpected disasters, are impacted by specific local elements such as geology, slope, land use, and human activity. As such, acquiring and monitoring information about landslides can be difficult and expensive.
• Based on historical experiences and mitigating variables including geology, rainfall, and human activity, India is categorised into vulnerability zones.
• Extremely Dangerous This zone include regions with considerable rainfall in the Western Ghats and Nilgiris, areas with intense human activity, and unstable mountainous terrain in the Himalayas, Andaman and Nicobar.
• Some places are comparatively safe from landslides, such as coastal areas of southern states, West Bengal (except from Darjiling), Assam (apart from Karbi Anglong), Rajasthan, Haryana, Uttar Pradesh, Bihar, and Assam.
• Landslides can effect development and spatial interaction in impacted areas by disrupting transportation infrastructure, diverting river courses to cause flooding, and impeding developmental activity.

Conclusion

In conclusion, successful disaster planning and mitigation methods require a grasp of the classification and types of natural hazards as well as disasters. We can lessen the effects of these occurrences on people’s lives, means of subsistence, and infrastructure by recognising and evaluating them, which will promote resilience and sustainable development in areas that are susceptible.

Classification and Types of Disasters and Natural Hazards- FAQs

What is the difference between a disaster and a natural hazard?

A natural hazard is a potential threat, while a disaster is the actual occurrence of a hazard causing significant harm and requiring assistance.

How can communities mitigate the impact of natural hazards?

Communities can reduce the impact of natural hazards through early warning systems, resilient infrastructure, preparedness training, and collaborative planning.

Can natural hazards be predicted accurately?

While advancements in monitoring improve accuracy, predicting natural hazards with precision remains challenging due to complex processes.

What are some examples of technological hazards?

Examples of technological hazards include industrial accidents, transportation incidents, nuclear incidents, and cybersecurity breaches.

Why is it important to understand the classification of disasters and natural hazards?

Understanding classification aids in targeted mitigation, resource allocation, public awareness, and coordination for effective disaster management.