Risk Factors and Perceived Restoration in a Town Destroyed by the 2010 Chile Tsunami

A large earthquake and tsunami took place in February 2010, affecting a significant part of the Chilean coast (Maule earthquake (Mw = 8.8). Dichato (37° S), a small town located on Coliumo Bay, was one of the most devastated coastal places and is currently under reconstruction. Therefore, the risk factors which explain the disaster at that time as well as perceived restoration 6 years after the event were analyzed in the present paper. Numerical modeling of the 2010 Chile tsunami with four nested grids was applied to estimate the hazard. Physical, socio-economic and educational dimensions of vulnerability were analyzed for pre- and post-disaster conditions. A perceived restoration study was performed to assess the effects of reconstruction on the community and a principal component analysis was applied for post-disaster conditions.
The vulnerability factors that best explained the extent of the disaster were housing conditions, low household incomes and limited knowledge about tsunami events, which conditioned inadequate reactions to the emergency. These factors still constitute the same risks as a result of the reconstruction process, establishing that the occurrence of a similar event would result in a similar degree of disaster. For post-earthquake conditions, it was determined that all neighborhoods have the potential to be restorative environments soon after a tsunami. However, some neighborhoods are still located in areas devastated by the 2010 tsunami and present a high vulnerability to future tsunamis. Therefore, it may be stated that these areas will probably be destroyed again in case of future events.