The Decision Support System for improved Tsunami Early Warning in Indonesia: Approach and Implementation

Abstract

In recent years numerous tsunami events in the Indian Ocean have shown how vulnerable human society and the environment is to this sudden-onset type of disaster. Especially the December 2004 tsunami demonstrated the need for an effective tsunami early warning system for the Indian Ocean. The German-Indonesian Early Warning System (GITEWS) project uses the best sensor technologies available today to detect indicators or evidence for a tsunami, combining those information with up-to-date modelling techniques and integrating them in a newly developed Decision Support System. Combining a-priori knowledge, simulation runs and analysis results with real-time information from different types of sensors, the newly developed Decision Support System (DSS) serve as a back-bone to allow an assessment for the tsunami threat at the earliest time possible and support the decision maker whether to issue a tsunami warning or not. GITEWS therefore adds additional components in order to achieve the best situation awareness possible by compiling a huge scenario-based repository of a-priori knowledge: A tsunami simulation system generates a large number of pre-calculated tsunami scenarios; in case of a potential tsunami, sensor observations can be compared and matched with these scenarios in order to find the most likely tsunami scenario descriptions, and a risk and vulnerability analysis component that helps to assess probable consequences and impacts on coastal communities exposed to tsunamis. Once the decision to disseminate a warning has been made, the DSS is able to generate regionalized warning messages, which are then transmitted to different dissemination systems using the standardized Common Alerting Protocol (CAP).