Types of Disasters — Set 11

Correct Answer: C. Tsunamis have much longer wavelengths and travel faster than wind-driven waves

Tsunamis have wavelengths of hundreds of kilometres and travel at speeds up to 800 km/h in the deep ocean — far faster and with far greater energy than wind-generated waves. In the deep ocean, tsunami waves may be less than a metre high but travel at jet aircraft speeds; as they reach shallow coastal waters they slow and grow in height, sometimes exceeding 30 metres. Tsunamis are not caused by tides; the name 'tidal wave' is a historical misnomer.

Correct Answer: B. Man-made industrial disaster

Mine fires, such as those in the Jharia coalfield in Jharkhand, are classified as man-made industrial disasters originating from human mining activities. Jharia has been burning underground for over 100 years, causing land subsidence, toxic gas emissions, and forced displacement of communities. Mine fires pose continuous risk to residents through ground collapse, toxic air pollution, and loss of livelihoods in coal-dependent communities.

Correct Answer: A. Glacial Lake Outburst Flood

GLOF stands for Glacial Lake Outburst Flood — a flood wave produced when the dam containing a glacially formed lake suddenly fails, releasing large volumes of accumulated meltwater. GLOFs are increasingly common in the Himalayas as glaciers retreat due to global warming, leaving behind unstable moraine-dammed lakes. The 2021 Chamoli disaster in Uttarakhand is linked to a GLOF event that devastated a hydropower project and killed over 200 people.

Correct Answer: C. Bhopal

Bhopal, the capital of Madhya Pradesh, was the site of the worst industrial disaster in Indian and world history — the 1984 MIC gas leak from the Union Carbide India Limited plant. The disaster killed an estimated 15,000–20,000 people in the immediate aftermath and long-term illnesses. The Bhopal Gas Tragedy Memorial Hospital continues to treat survivors and their descendants who suffer from gas-related chronic illnesses.

Correct Answer: B. Ground shaking, surface rupture, and triggered landslides

Earthquakes primarily cause destruction through ground shaking (which collapses buildings and infrastructure), surface fault rupture, liquefaction of saturated soils, landslides triggered by seismic shaking, and tsunamis generated by submarine earthquakes. Fires ignited by broken gas lines are also a major secondary hazard in urban areas following earthquakes. The Bhuj earthquake of 2001 caused massive destruction primarily through ground shaking that collapsed poorly constructed masonry buildings.

Correct Answer: A. Occur only in the tropics and form over warm ocean water

Tropical cyclones form exclusively over warm tropical ocean waters (sea surface temperature above 26°C) between roughly 5° and 20° latitude where the Coriolis effect is sufficient to initiate rotation. They derive their energy from the evaporation of warm ocean water and its latent heat release when moisture condenses in towering convective clouds. The Bay of Bengal and Arabian Sea are the two tropical ocean basins from which cyclones make landfall in India.

Correct Answer: C. IMD

The India Meteorological Department (IMD) operates a network of Doppler Weather Radars (DWR) strategically located along India's coastline for cyclone tracking and intensity estimation. IMD has significantly expanded its DWR network in recent years to improve coverage and reduce the cyclone warning lead time from 24 hours to 72–120 hours. INCOIS handles tsunami warnings while ISRO provides satellite data that complements IMD's radar and surface observation network.

Correct Answer: B. Long-term risk reduction, early warning, and resilience building

Slow-onset disasters like drought, desertification, and sea-level rise are most effectively managed through long-term risk reduction strategies including watershed conservation, drought-resistant agriculture, sustainable land management, and early warning systems. Unlike sudden disasters requiring immediate rescue, slow-onset events allow time for gradual policy interventions, social protection schemes, and livelihood diversification programmes. The PM Fasal Bima Yojana (crop insurance) and PM Krishi Sinchai Yojana (irrigation) are key instruments for slow-onset disaster management in India.

Correct Answer: C. Dam burst floods

Floods caused by dam failure are specifically termed 'dam burst floods' or 'dam break floods' — a type of man-made disaster involving sudden catastrophic release of stored reservoir water. Dam burst floods typically have very short warning times and can cause enormous destruction downstream due to the high volume and velocity of released water. The Machhu Dam failure of 1979 in Gujarat, which killed an estimated 25,000 people, is one of India's deadliest dam burst disasters.

Correct Answer: B. Addressing multiple hazards in an integrated manner based on shared risk factors

A multi-hazard approach integrates risk assessment and management across multiple hazard types — recognising that many regions face overlapping risks from earthquakes, floods, cyclones, and other hazards that share common underlying vulnerabilities. This approach enables more efficient use of resources and avoids duplication across sectoral disaster management plans. India's National Disaster Management Plan (NDMP) 2016 and the Sendai Framework both endorse the multi-hazard approach.