📌 Chapter Snapshot
4
Earthquake Zones in India
2005
Disaster Management Act
2007
Indian Tsunami Early Warning System
1984
Bhopal Gas Tragedy
- This chapter covers major natural & man-made disasters — Earthquake, Tsunami, Landslide, Flood, Drought, Cyclone — along with India's institutional disaster management framework.
- Also includes other notable disaster events: Cloudburst, Bhopal Gas Tragedy, and Chernobyl Disaster.
⚡ QUICK RECALL
Disaster Management Act, 2005 established the three-tier structure: National, State, and District Disaster Management Authorities.
🌍 Earthquake
- Tectonic vibrations of the Earth's crust — result of instability in the fundamental rocks.
Causes
- Movement of plate tectonics
- Earth's rotation
- Volcanic activity
- Aquatic load, etc.
Earthquake Zones of India
| Zone | Risk Level | States / Regions |
|---|---|---|
| Zone-2 | Minimum impact (Intensity 6 or less) | Northern & eastern Rajasthan, Tamil Nadu, Northern Andhra Pradesh, Chhattisgarh, etc. |
| Zone-3 | Moderate impact (Intensity VII) | Kerala, Goa, Gujarat, Uttar Pradesh, West Bengal, Odisha, etc. |
| Zone-4 | High impact (Intensity VIII) | Jammu & Kashmir, Himachal Pradesh, Delhi, Sikkim, etc. |
| Zone-5 | Very high impact (Intensity IX and above) | North-Eastern India, Uttarakhand, Western Himachal Pradesh, Andaman Islands, etc. |
⚠ EXAM TRAP
Delhi falls in Zone-4 (High impact) despite being a plains capital city — often wrongly assumed to be in a lower-risk zone.
🌊 Tsunami
- Tsunami is a Japanese word.
| Causes | Effects |
|---|---|
| Earthquake, volcanic eruption, submarine landslide | Coastal ecosystem affected, spread of toxic waste in coastal areas, migration of exotic species, damage to infrastructure, etc. |
Tsunami Management
- Construction of sea walls.
- Coastal plantation of mangrove vegetation, etc.
- Establishment of Indian Tsunami Early Warning System (2007) — to give information and warning about tsunami effects.
⛰ Landslide
- Downward falling of rocks along the slope due to gravity.
- Common occurrence in Himalayan regions/states of India.
| Causes | Effects | Management |
|---|---|---|
| Rainfall and snowfall, mining and excavation, deforestation, infrastructure development | Damage to infrastructure, obstruction in river flow, hindrance in grazing, etc. | Afforestation, ban on mining, control over construction, contour farming, etc. |
🌊 Flood
- Sudden rise in water in rivers, lakes, etc.
| Causes | Effects | Management |
|---|---|---|
| Heavy rainfall, change in river course, increase in siltation, faulty agricultural practices, faulty agriculture irrigation, etc. | Destruction of basic infrastructure, spread of water-borne diseases, soil erosion, soil salinisation, etc. | Construction of embankments, cleaning of river beds, development of flood warning systems, etc. |
☀ Drought (Atmospheric Disaster)
| Causes | Effects |
|---|---|
| Low rainfall for a long time, decrease in reservoir and groundwater level, water scarcity | Agriculture and animal husbandry affected, human & animal migration, famine, etc. |
Major Programmes for Drought Management
- Desert Development Programme — 1977–78
- National Watershed Development Project — 1990–91, etc.
⚠ EXAM TRAP
Desert Development Programme (1977–78) predates the National Watershed Development Project (1990–91) by over a decade — don't swap the order.
🌀 Cyclone
- A low pressure centre — occurs in both Temperate and Tropical regions (Tropical cyclones are more destructive).
- Effects → Floods, coastal areas affected, etc.
- Protection → Promoting mangrove vegetation in coastal areas.
🏛 Disaster Management
- Formation of National, State and District Disaster (Management) Authorities.
- Established under the Disaster Management Act, 2005.
⚠ Other Disasters
| Disaster | Details |
|---|---|
| Cloudburst | Sudden heavy rainfall, especially in hilly areas | Causes flood problems |
| Bhopal Gas Tragedy | Bhopal, 3rd December 1984 | Leakage of methyl isocyanate poisonous gas |
| Chernobyl Disaster (Ukraine) | Industrial nuclear incident, 26th April 1986 |
⚡ QUICK RECALL
Bhopal Gas Tragedy (1984, India) and Chernobyl Disaster (1986, Ukraine) occurred just 2 years apart — both are landmark man-made industrial disasters in world history.
📋 Master Quick-Revision Table
| Topic | Key Fact |
|---|---|
| Earthquake | Tectonic vibrations of Earth's crust | Causes: plate tectonics, volcanic activity |
| Zone-2 | Minimum impact | Intensity 6 or less | Rajasthan, TN, N. AP, Chhattisgarh |
| Zone-3 | Moderate | Intensity VII | Kerala, Goa, Gujarat, UP, West Bengal, Odisha |
| Zone-4 | High | Intensity VIII | J&K, HP, Delhi, Sikkim |
| Zone-5 | Very High | Intensity IX+ | North-East India, Uttarakhand, W. HP, Andaman Islands |
| Tsunami | Japanese word | Causes: Earthquake, volcanic eruption, submarine landslide |
| Indian Tsunami Early Warning System | Established 2007 | Warning about tsunami effects |
| Landslide | Downward falling of rocks due to gravity | Common in Himalayan states |
| Flood | Sudden rise in water | Causes: heavy rainfall, river course change, siltation |
| Drought | Atmospheric Disaster | Low rainfall, groundwater decline, water scarcity |
| Desert Development Programme | 1977–78 |
| National Watershed Development Project | 1990–91 |
| Cyclone Protection | Promoting mangrove vegetation in coastal areas |
| Disaster Management Act | 2005 | Formation of National, State & District Disaster Authorities |
| Cloudburst | Sudden heavy rainfall in hilly areas | Causes flood problem |
| Bhopal Gas Tragedy | 3 December 1984 | Methyl isocyanate gas leak |
| Chernobyl Disaster | Ukraine | 26 April 1986 | Industrial nuclear incident |