Disasters in India: Types, Causes, Risk

Disasters in India are broadly categorized into two types: natural disasters arising from environmental processes, and man-made disasters resulting from human activity or technological failures."

Natural Disasters in India 

The catastrophic events that arise from natural processes and phenomena are called natural disasters. They cause significant loss of life, property, and livelihoods.

Some key examples include earthquakes, floods, cyclones, droughts, landslides, and tsunamis. 

These disasters in India occur both seasonally like monsoon floods and cyclones. They also occur suddenly without warning like earthquakes and cloudbursts. 

They expose large populations to repeated insecurity, disruption, and large economic losses. 

India’s diverse geography and climate make it highly vulnerable. With over two-thirds of its states and union territories facing one or more types of natural hazards each year, affecting millions of people and causing thousands of deaths annually. 

1. Floods: 

   

   1. When excessive rainfall, snowmelt, or river overflow inundates low-lying areas. The accumulation of water causes floods because water accumulates faster than land or drainage systems can absorb or discharge it.

   2. The causes of floods are: 

      1. Heavy monsoon rains

      2. cyclones, dam breaches

      3. Urbanization

      4. poor drainage

      5. encroachment on floodplains.

   3. Flood-Prone Zones: India’s most affected regions include the Indo-Gangetic plains. The plains include the regions of Bihar, Uttar Pradesh, West Bengal and Assam. The coastal states (Odisha, Andhra Pradesh), and urban centres like Mumbai, Chennai, and Delhi are also prone to floods. Nearly 12% of India’s land area and 40 million hectares are flood-prone.

   4. Examples: Punjab Floods in August 2025; 1400+ villages submerged heaviest in decades.

2. Cyclones: 

   

   1. Intense low-pressure systems characterized by spiral winds and heavy rain, formed when warm ocean waters (above 27°C). They cause moisture laden air to rise, creating a vortex because of Earth’s rotation. This is also called Coriolis force.

   2. Causes: 

      1. Triggered by high sea surface temperatures, 

      2. low vertical wind shear, and pre-existing low-pressure zones over tropical seas

      3. They occur most commonly during pre- and post-monsoon seasons (April–May & October–December).

   3. Cyclone-Prone Zones: About 5,700 km of India’s 11,098 km coastline is vulnerable. The specific areas towards the Bay of Bengal Side  Odisha, Andhra Pradesh, West Bengal and Tamil Nadu. On the Arabian Sea Side and Gujarat, Maharashtra.

3. Earthquakes:

   

   1. Earthquakes occur when stress release along tectonic plate boundaries or faults generates ground shaking. This builds up along stress which is released from tectonic plate boundaries and faults.  India is in a convergent tectonic boundary. The Indian Plate is subducting under the Eurasian Plate. This makes the region susceptible to earthquakes.

   2. Seismic Zones: Around 59% of India’s land area is prone to earthquakes. The active regions include the Himalayan states, Northeast India, and parts of Gujarat and Maharashtra. The affected areas fall under seismic zones IV and V.

   3. Examples:The 2001 Gujarat earthquake (7.7 Mw) caused significant devastation. While frequent tremors continue in the Himalayan region, underscoring the region’s ongoing tectonic instability.

4. Landslides:

   

   1. Rapid downflow of rock, soil, and debris on steep terrains which is triggered mainly by heavy rainfall, earthquakes, or snow/glacial melt.

   2. Landslide-Prone Zones: Potential landslide zones are almost 12.6% of area in India. The areas include the northwestern part of the Himalayas, the northeastern hills, and Western Ghats.

   3. Examples: The tragic cloudburst in Uttarakhand in June 2013, and in August 2025 in Uttarkashi (Dharali village). In 2024, the region of Manimahesh Yatra in Himachal Pradesh, witnessed landslides.

5. Droughts: 

   

   1. When there are extended stretches of insufficient rainfall coupled with a deficit in moisture, there are delays in monsoons. Such delays create water shortages which in turn affect agriculture and the livelihoods dependent on agriculture.

   2. Causes: Some reasons are erratic monsoon tendencies, delayed commencement or premature retreat of rains. The heightened temperatures resulting in increased evaporation also add to droughts. Other human-induced causes such as the depletion of groundwater and deforestation.

   3. Drought-Prone Zones: Around 30% of India’s geographical area is drought-prone. This includes Maharashtra (Marathwada, Vidarbha), Rajasthan, and Andhra Pradesh (Rayalaseema). Parts of Karnataka, Telangana, the Bundelkhand region (MP-UP), and portions of Odisha, Gujarat, and Jharkhand.

6. Heatwaves: 

   1. The Extended durations of unusually high temperatures, particularly exceeding 45°C cause Heatwaves. They are observed during the pre-monsoon period (March-June) and summer months.

   2. Causes:Heat waves are getting more frequent and intense due to several factors.

      1. Stagnant high-pressure systems trap heat, and reduced cloud cover allows more sunlight to reach the ground.

      2. Cities become hotter because of the urban heat island effect.

      3. Human driven climate change is worsening the situation.

   3. Heatwave Prone Areas: The worst heatwaves happen in North, Central, and Western India. The states most affected are Rajasthan, Delhi-NCR, Punjab, UP, Odisha, Maharashtra, and Telangana. IMD defines a heatwave when max temperature exceeds 40°C (plains) or is 4.5°C+ above normal.

7. Glacial Lake Outburst Floods (GLOFs):

   1. Water in glacial lakes can flood downstream when ice or moraine dams break. This can cause serious floods downstream.

   2. Causes: Lake banks that are unstable and glacially fed lakes are susceptible to overdue glacial outburst floods as a result of climate change, heavy precipitation, avalanches, landslides and earthquakes. 

   3. GLOF Prone Zones: 7,500+ glacial lakes mapped in Indian Himalayas, of which 22% are showing recent area expansion (CWC 2025). 

   4. Examples: In Oct 2023: Sikkim (South Lhonak lake) GLOF caused 55 deaths.

8. Cloudbursts:

   1. Very heavy rain, over 100 mm per hour, in small areas like hills or mountains can cause flash floods and landslides.

   2. Causes: It is caused by elevation induced (Orographic) uplift of moisture-laden winds, rapid condensation, and unstable atmosphere in mountainous terrain. It occurs especially during the monsoon.

   3. Cloudburst Prone Zones: Himalayan states like Uttarakhand, J&K, Himachal, Ladakh, parts of NorthEastern India. About 5–7% of all rainfall related disasters in mountains are linked to cloudbursts.

   4. Examples: In Aug 2025: Uttarkashi (Uttarakhand) multiple cloudbursts, destroying villages and causing dozens of casualties.

9. Forest fires: 

   1. Forest Fires are uncontrolled burning of forests and vegetation, often spreading rapidly and causing extensive ecological and economic damage.

   2. Causes: Natural causes: lightning, extreme heat/drought, accidental or manmade causes like campfires, stubble burning. They get aggravated by prolonged dry spells, deforestation, invasive species, and climate change.

   3. Forest Fires Prone Zones: According to the Forest Survey of India (FSI), around 36% of forests are prone to fires.

10. Tsunamis: 

    1. The giant sea waves caused by undersea earthquakes, volcanic activity, or landslides are called tsunamis. It can cause catastrophic flooding on the coast.

    2. Causes: Sudden displacement of the sea floor (earthquake of >7.5 magnitude), submarine volcanic eruptions or landslides displace massive water columns, generating long-wavelength waves.

    3. Tsunami Prone Zones: The 5,700 km of Indian coastline at some risk, highest hazard for Andaman & Nicobar Islands, eastern coast (Tamil Nadu, Pondicherry, Andhra, Odisha).

    4. Examples: Dec 2004: Indian Ocean Tsunami 9.1 Mw quake off Sumatra causing almost 11,000 deaths in Andaman & Nicobar and east coast, colossal destruction. 

Man-Made Disasters in India 

Human initiated calamities refer to disasters caused by human activity, carelessness, or technological breakdowns.These disasters result from human activity rather than natural processes. They include industrial or chemical accidents, fires, accidents in transportation, collapses of structures, nuclear incidents, or large-scale environmental pollution.  

These disasters result in loss of life, property, and desolation of the environment, leading to additional strain on emergency systems in India. Notable examples of these disasters include the Bhopal Gas Tragedy and other avoidable tragedies like the mining accidents, major train/road accidents and fires/leaps in urban settings. These tragedies highlight the urgent need for sound systematic safety and prevention protocols.

• Industrial accidents: 

  • Catastrophic incidents in factories or facilities involving hazardous chemicals or industrial processes, resulting in mass casualties, health hazards, and environmental damage.

  • Causes: Typically triggered by equipment failure, safety lapses, poor maintenance, human error, or non-compliance with regulations.

  • Examples: Bhopal Gas Tragedy (1984);Pesticide plant’s MIC gas leak in Bhopal, Madhya Pradesh. Over 3,800 deaths instantly, with 15,000–20,000 total estimated fatalities and lingering multi-generational health/environmental impacts.

• Urban floods:

  • Urban floods refer to the inundation of city areas due to intense rainfall overwhelming drainage systems, often amplified by poorly planned cities and encroachment.

  • Causes: Key drivers include inadequate or blocked stormwater drains, encroachment on traditional water bodies and floodplains, rapid unplanned construction, and compounding effects of climate change causing more intense rain events.

  • Urban Flood Prone Zones: Major Indian metros like Mumbai, Chennai, Delhi, Bengaluru, Hyderabad, Kolkata, and Guwahati are highly susceptible. Over 50 Indian cities are classified as flood-prone, with about 26% of India’s urban land area at some flood risk.

  • Examples: Chennai (2015) saw the worst city flood in a century. Over 400 people lost their lives, $3 billion in losses, large-scale displacement, and infrastructure failure.

• Biological Disaster:

  • Events caused by the spread of pathogens (viruses, bacteria, etc.), biological agents, or toxins, leading to widespread illness, death, or ecosystem damage; also includes bio-terrorism and laboratory accidents.

  • Causes: Triggers may include zoonotic spillovers, pandemic outbreaks, accidental laboratory releases, bioterror attacks, and inadequate public health response.