Disaster

Topic: Natural Hazards and Disaster Management in India · NCERT: Class 11, Ch 6 "Natural Hazards and Disasters: Causes, Consequences and Management"

Meaning

A disaster is an undesirable event that strikes quickly with little or no warning, is caused by forces largely outside human control, and causes or threatens serious damage to life and property, including the death and injury of many people. It needs help beyond the normal statutory emergency services (police, fire brigades and hospitals on a normal day).

It matters because about two-thirds of India's area and people are vulnerable to disasters (NCERT). Indian policy has also moved from giving relief after a disaster to reducing risk before one strikes.

Explanation

How a hazard becomes a disaster

• Change in nature is value-neutral. For nature, a flood or an earthquake is just a process. It is neither good nor bad.
• For people, change is value-loaded. It is "good" if it helps them and a "disaster" if it harms their lives and property.
• A flood in an empty valley is only a natural event.

• The same flood in a crowded town is a disaster.

• The chain:

• A natural hazard exists. This is a possible danger, such as an active fault line under the Himalayas.
• People and buildings are placed in its path (towns, dams, roads).

• The hazard strikes and the damage is large-scale. Only then is it a disaster.

• Simple test: if the affected community cannot cope using only its own resources, the event is a disaster.

• Each disaster is unique. Its effects depend on the local socio-environmental setting, meaning the local land, climate, economy, housing and social groups.
• The same cyclone does far more damage in a poor coastal district than in a well-prepared one.

Why losses keep rising: vulnerability, exposure and risk

• Vulnerability: how easily people, buildings, economies and the environment can be harmed by a hazard. It is high where houses are weak, people are poor, and warning and rescue systems are poor.
• Technology raises vulnerability (NCERT):
• Embankments, pumps, tall buildings and reclaimed land give people the confidence to settle in risky places.
• So people crowd into floodplains and coastal megacities.

• More people and property sit in danger zones, so vulnerability rises even when the hazard itself has not grown.

• Exposure (UNDRR): the people, infrastructure, housing, production capacity and other human assets located in hazard-prone areas [3].

• Disaster risk (UNDRR): the possible loss of life, injury, or destroyed or damaged assets over a given period of time. It is worked out using probability, as a function of hazard, exposure, vulnerability and capacity [3].
• Working formula: Risk = Hazard × Exposure × Vulnerability ÷ Capacity
• Capacity (or coping capacity) means the skills, money, institutions and plans a community can use to manage a hazard. More capacity means less risk.

• Resilience is the ability to absorb a shock, adapt and recover quickly.

• Policy lesson: we cannot stop a cyclone, but we can cut the risk:

• move people out of danger zones (less exposure);
• build strong houses (less vulnerability);
• set up warnings and shelters (more capacity).

Types of disaster

• Natural disasters (NCERT Class 11, Table 6.1):

Class	Examples
Atmospheric	tropical cyclones, thunderstorms, lightning, tornadoes, blizzards, drought, hailstorm, frost, heat wave (loo), cold wave
Terrestrial	earthquakes, volcanic eruptions, landslides, avalanches, subsidence (the ground slowly sinking), soil erosion
Aquatic	floods, tidal waves, ocean currents, storm surge (sea water pushed onto land by a cyclone's winds), tsunami
Biological	colonisers such as locusts, insect infestation, and diseases such as bird flu and dengue

• Human-made disasters:
• Direct: human action itself causes the disaster. Examples: the Bhopal gas tragedy (1984), Chernobyl (1986), wars, the release of CFCs (chlorofluorocarbons, which harm the ozone layer), greenhouse gases and pollution.
• Indirect: human action makes a natural hazard worse.
  • Forests are cut on hill slopes.
  • Roots no longer hold the soil, and rain runs off fast.
  • The result is more landslides in the hills and more floods downstream.

Where it occurs

• India's hazard profile (NIDM):
• Earthquakes: about 58.6% of the landmass [2]. This covers the Himalayan belt (J&K to Arunachal Pradesh), the North-East, Kachchh (Gujarat) and the Andaman and Nicobar Islands.
• Floods and river erosion: over 40 million ha, about 12% of the land [2]. The worst-hit areas are the Ganga–Brahmaputra plains (Assam, Bihar, Uttar Pradesh, West Bengal).
• Cyclones and tsunamis: about 5,700 km of the 7,516 km coastline [2]. The east coast is hit more often, especially Odisha, Andhra Pradesh, Tamil Nadu and West Bengal.
• Drought: 68% of the cultivable area [2]. This includes the dry west (Rajasthan, Gujarat) and the rain-shadow Deccan (interior Maharashtra, Karnataka, Telangana).

• Landslides and avalanches: hilly areas, mainly the Himalayas and the Western Ghats [2], for example Uttarakhand and Himachal Pradesh.

• Rising exposure: coastal megacities such as Mumbai (west coast, Maharashtra) and Chennai (east coast, Tamil Nadu).

• Industrial disaster: Bhopal, Madhya Pradesh. Methyl isocyanate (MIC) gas leaked from the Union Carbide India Ltd pesticide plant on the night of 2-3 December 1984.
• World: Chernobyl nuclear accident (Ukraine, then USSR, 1986).
• Biological disasters:
• The desert locust upsurge (2019-20) came in from Pakistan and attacked crops in Rajasthan and Gujarat.

• COVID-19 was notified as a disaster under the DM Act 2005 in March 2020.

• Legal frame:

• The Disaster Management Act, 2005 set up the NDMA (chaired by the Prime Minister), the SDMAs (state level) and the DDMAs (district level).
• The DM (Amendment) Act, 2025 added national and state disaster databases and Urban Disaster Management Authorities [4][5].

Don't confuse with

• Natural hazard: only a possible threat with no loss yet, such as a steep Himalayan slope. A disaster is the actual event with large-scale losses that the community cannot handle alone, such as a landslide that buries a village.
• Vulnerability: how easily people and assets can be harmed. It is a condition that exists before the event. A disaster is the result when a hazard meets vulnerable people.
• Disaster risk: the possible future loss over a given time, worked out from hazard, exposure, vulnerability and capacity [3]. A disaster is the loss that has actually happened.
• Direct vs indirect human-made disaster: Bhopal, Chernobyl and CFC release are direct. Floods and landslides made worse by deforestation are indirect.

Prelims Hooks

• A hazard becomes a disaster only when its damage is large-scale and beyond the community's own coping capacity.
• Drought is an atmospheric disaster. Tsunami, storm surge and tidal waves are aquatic. Subsidence and soil erosion are terrestrial (NCERT Table 6.1).
• Bhopal gas tragedy: methyl isocyanate (MIC), Union Carbide pesticide plant, 2-3 December 1984, Madhya Pradesh. It led to the Environment (Protection) Act 1986 and the Public Liability Insurance Act 1991.
• India's exposure: about 58.6% of land is earthquake-prone, about 12% (40 million ha) is flood-prone, about 5,700 km of the 7,516 km coastline faces cyclones and tsunamis, and 68% of cultivable area is drought-prone [2].
• Order of global frameworks: Yokohama (1994) → Hyogo (2005-2015) → Sendai (2015-2030). The UNDRR terminology was adopted by the UNGA on 2 February 2017 [3].
• COVID-19 was notified as a disaster under the DM Act 2005 in March 2020. A pandemic counts as a biological disaster.

Mains Points

• Why disaster losses in India rise even when hazards do not grow (GS-I/III):
• Technology-led crowding into floodplains and coastal megacities (Mumbai, Chennai) raises exposure.
• India's large size, colonial past, social discrimination and large population raise vulnerability. Poor people, Dalits, tribal people and women often live in the most unsafe places and get help last.

• So policy must cut risk (Risk = H × E × V ÷ C), not only give relief.

• Human-made and indirect disasters:

• Deforestation, unscientific land use and building on fragile Himalayan slopes and river beds turn hazards into disasters.
• Bhopal (1984) shows the industrial side: chemical units placed next to dense, poor settlements.

• The answers are land-use zoning, environmental impact assessment and liability laws (EPA 1986, PLIA 1991).

• Shift from relief to risk reduction (GS-III):

• Region-specific plans: earthquake-safe building codes for the Himalayas and North-East, flood plain zoning for the Ganga–Brahmaputra plains, cyclone shelters and early warning on the east coast, and drought-proofing for the 68% drought-prone cultivable area [2].
• DM (Amendment) Act 2025: it reflects Sendai Framework (2015-2030) goals. It adds disaster databases, Urban DMAs (chaired by the Municipal Commissioner, with the District Collector as vice-chairperson) and NDMA audits of state preparedness [4][5].

Related concepts

• Natural hazard
• Vulnerability
• Classification of natural disasters
• Human-made disasters
• Bhopal gas tragedy
• Biological disasters

Read more

• Hazards, disasters and vulnerability