Tsunami risk assessment for local communities in Indonesia to provide information for early warning and disaster management

Abstract

Decision makers at the community level need detailed information on tsunami risk in their area. Knowledge on potential hazard impact, exposed elements such as people, critical facilities and lifelines, coping capacity and recovery is crucial to plan precautionary measures to mitigate potential impacts of tsunamis on society and the environment. In this study a community level risk assessment methodology is presented. Thereby the risk assessment encompasses and discloses weaknesses within the components exposure, susceptibility, response and recovery potential at the community level. This means that detailed information is generated on dynamic exposure factors (e.g. day and night distribution of exposed people, location and properties of critical facilities), people ability to respond and evacuate potential damage on the built environment, local emergency response capability and local ability for rehabilitation and recovery. To quantify these risk components detailed surveys have been conducted to collect the necessary information. Based on these data on socio-economic household properties, critical facilities locations, building damage potential, potential vertical and horizontal evacuation areas and their properties an in-depth risk assessment has been conducted. The study presents first results of studies which have been performed in several pilot areas in Indonesia. They are based on common developed methodologies at the community level. The results and products can be used for tsunami disaster adaptation and mitigation planning, but also to improve people and institutional preparedness and awareness. General guidelines on how to conduct the assessment are being developed and shall be incorporated into community level disaster management strategies.