Which of the following natural hazards is not hydro-meteorological ?
2017
Which of the following natural hazards is not hydro-meteorological ?
Answer: D. Tsunami — Concept: Natural hazards are classified by the Earth-system process that generates them. A hydro-meteorological hazard originates in atmospheric, hydrological…
- A.
Snow avalanche
- B.
Sea erosion
- C.
Tropical cyclone
- D.
Tsunami
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Show answer & explanation
Correct answer: D
Concept: Natural hazards are classified by the Earth-system process that generates them. A hydro-meteorological hazard originates in atmospheric, hydrological or oceanographic processes — the movement of air, water and heat at and above the Earth's surface. A geophysical hazard originates in solid-Earth processes — crustal movement, faulting, volcanism and the mass movement of rock.
Application: Test each hazard in the list against the process that actually generates it:
Hazard | Generating process | Process group |
|---|---|---|
Snow avalanche | Fresh snowfall, rain-on-snow, wind loading and temperature change destabilise a snowpack | Atmospheric / hydrological |
Sea erosion | Wave energy, tidal and longshore currents and storm surge wear back the shoreline | Oceanographic / hydrological |
Tropical cyclone | Evaporation from a warm ocean surface and latent-heat release drive a rotating low-pressure system | Atmospheric / meteorological |
Tsunami | Sudden vertical displacement of the sea floor by a submarine fault rupture, landslide or volcanic collapse | Solid-Earth / geophysical |
Cross-check: The ocean carries a tsunami but does not create it — remove the sea-floor rupture and no wave forms, whereas removing the atmospheric or wave forcing removes the avalanche, the coastal erosion and the cyclone entirely. The NDMA National Disaster Management Plan (2016) draws the same line in its hazard table: avalanche and coastal erosion are placed under hydrological hazards and cyclone under meteorological hazards, while tsunami is placed under geophysical hazards.
Hence the hazard in this list that is not hydro-meteorological is the Tsunami.