On December 2004, tsumani brought havoc on 14 countries including India. Discuss the factors responsible for occurrence of Tsunami and its effects on life and economy. In the light of guidelines of NDMA (2010) describe the mechanisms for preparedness to reduce the risk during such events. (15 Marks)

A tsunami is a series of long waves generated by sudden displacement of the sea floor, with risk determined by both the triggering event and coastal vulnerability.

Causes and effects

• Subduction-zone earthquakes, submarine landslides, volcanic eruptions and rare meteorological or impact events can displace water.
• Near shore, shallow water slows waves and increases their height, causing inundation and powerful currents.
• Deaths, injuries, displacement, salinisation, livelihood loss, damaged ports, roads, housing and tourism create long economic disruption.

Preparedness under NDMA approach

• Maintain the Indian Tsunami Early Warning Centre, seismic and sea-level sensors, 24×7 dissemination and last-mile alerts.
• Map inundation zones; enforce coastal land-use regulation, resilient construction and vertical/horizontal evacuation shelters.
• Prepare marked evacuation routes, community volunteers, drills, school awareness, accessible warnings and interoperable emergency communication.
• Pre-position relief, protect critical infrastructure and conduct regular multi-agency exercises.

Early warning saves lives only when communities trust, understand and can act on it.

Keywords: tsunami; NDMA; coastal resilience.