Results of a loss inspection on the west coast of Thailand

The tsunami that followed the earthquake off the coast of northern Sumatra in the Indian Ocean on 26 December 2004 triggered the worst human disaster caused by a natural hazard event since the Tangshan earthquake in China in 1976. Experts from the Geo Risks Research team at Munich Re have now analysed the results of a loss inspection on the west coast of Thailand with the result that risks, loss potentials, and risk premium rates can be better assessed in the future.

Indonesia, Thailand, Malaysia, Sri Lanka, India, the Maldives, Kenya, and Somalia — the affected area was huge. For this loss inspection, the geo experts chose the tourist centres of Khao Lak and Phuket in Thailand because the effects of the tsunami and the damage to hotel complexes and buildings observed there are most readily transferable to insured risks in other exposed coastal areas.

The investigations show which factors influence the scale of damage caused by tsunamis. The main factors are wave height, depth of flood penetration, structural quality of buildings, plus velocity of flow and the volume of debris carried by the wave.

With speeds of 30—40 km/h, the Sumatra tsunami is classed as being relatively slow. Other events — like the tsunami on the north coast of Papua New Guinea (Sissano Lagune) in 1998 — reached speeds of 70 km/h. The loss inspection revealed that, in contrast, the volume of sediment and debris in the Sumatra tsunami was comparatively large.