Framework for evaluating the maintenance of a Tsunami Early Warning System (TEWS) – A pilot case study in Patong, Thailand, of social and technical quality indicators

: Due to a tsunami being a rapid event (minutes or hours), it is necessary to have disaster risk reduction measures in place well in advance. TEWS is a warning system for reducing the consequences of a tsunami. A successful TEWS requires that i) people are aware of the risk, ii) people are prepared to evacuate and iii) the TEWS is working properly. This study aims to develop a framework with key quality indicators for technical, social, and governance maintenance of a TEWS, emphasizing the chain of activities from tsunami detection to evacuation. The framework is extended to novel indicators involving memory keeping and evacuation signage. The TEWS etsablished in Patong, following the Indian Ocean tsunami disaster 2004, is used as a pilot case study to test the framework related to technical and social maintenance by conducting a retrospective long-term analysis years 2005–2022. Data is collected from research and news articles 2005–2022, as well as field observations of Patong in 2022. The result shows that during these years there have been several events and actions that highlight both problems and positive developments related to technical and social maintenance of the TEWS. Because tsunamis are fast occurrences, dependable TEWS are vital.