Rebuilding after Disaster - Engineering Lessons from the 2004 Tsunami.

On 26th December 2004 a magnitude 9 earthquake occurred off the west coast of northern Sumatra, Indonesia. The sudden and violent vertical displacement of the sea floor caused a disturbance to the overlying water column, which generated waves (tsunami) that propagated rapidly across the whole of the Indian Ocean. Typically, in open ocean waters, these waves have long wavelengths of the order of 200km and low trough to crest amplitudes. These properties allow them to conserve energy as they propagate over large distances. As the waves enter the shallower waters of coastal areas, their amplitude increases dramatically and their velocity reduces, resulting in violent wave impacts and extensive flood inundation inland. Unprepared for such a natural disaster and with no warning systems in place, more than 225,000 people died in South and Southeast Asia, and several million were left homeless. Liam McCarton, worked in Sri Lanka from 2005 to 2007 as Project Manager for post tsunami reconstruction programs. In this article he discusses some of the technical and humanitarian challenges involved in managing a reconstruction program in a developing country and presents some of the lessons learnt.