Answer:

1. A tsunami is a series of waves originated in a body of water by an impulsive disturbance that vertically displaces the water column. Earthquakes, landslides, volcanic eruptions etc can generate tsunamis.
2. Tsunamis are one of the most destructive natural hazards. The 2004 Indian Ocean tsunami was among the deadliest disasters in human history with over 290,000 people killed or missing in 14 countries bordering the Indian Ocean.
3. Disaster management is a multi disciplinary area in which a wide range of issues that range from forecasting, warning, evacuation, search and rescue, relief,reconstruction and rehabilitation are included.
4. The following steps are taken in the tsunami disaster management.

Risk assessment and vulnerability analysis: This involves collecting historical tsunami data and run ups for better future estimation of tsunami hazard. The Indian National Centre for Ocean Information Services (INCOIS), Hyderabad compiles databases of tsunami earthquakes and collects post tsunami data for future reference. Risk assessment and vulnerability analysis further consists of :-

• Preparations of a coastal vulnerability map: These areas are among the worst affected in the tsunamis.
• Role of the Indian Naval Hydrographical Department: The INHD has built 8 survey ships to monitor the tsunami waves.
• Using Geographic Information Systems (GIS) to enhance the risk evaluation exercises.
• Using satellite imagery for monitoring purposes.

Tsunami preparedness – The following are the components of tsunami preparedness.

• Warning system components and instruments
• Warning on flooding of critical areas.
• Releasing tsunami bulletins.
• Circulating early tsunami warnings.
• Creating public awareness.
• Educating people on tsunamis.
• Being medically prepared.

Structural mitigation measures – There Is a need to identify tsunami resilient construction practices and ensure their strict compliance. Several premier institutes of the country are in the process of designing tsunami resistant building for tsunami prone coastal areas. Following are some of the structural mitigation measures which should be taken :-

• There is a need for new standards for protection of structures against tsunami.
• Building shelters for storm surges and tsunamis.
• Protecting seafronts and lifeline structures.
• Creating specific design principles for tsunami.

Emergency tsunami response – A coordinated and effective response system is required at all levels. Response to early warning would ensure safe evacuation and minimal loss to property. Following are the ways by which an efficient emergency tsunami response system can be built :-

• Conducting emergency search and rescue.
• Providing emergency relief.
• Improving tsunami response.
• Constructing shelters.
• Carrying out evacuation plans.
• Providing instant medical assistance.