Analysis of Tsunami Evacuation Triggers in Indonesia

Abstract

 Tsunami events in Indonesia from 2010 to 2018 show that people respond differently and were not evacuated uniformly. A standard model of evacuation trigger ranking was developed using nine post-disaster evacuation surveys and shows that there are 6 main tsunami evacuation triggers in Indonesia with seeing other evacuees was the prevalent trigger and gave the high influence. Analyses of videos of human behaviors during the evacuation of the 2018 Palu tsunami revealed that (1) late evacuees who noticed the arrival of a tsunami had a greater influence than early evacuees, (2) influence of evacuation triggers increase gradually as the distances between the trigger sources and persons decrease, and (3) evacuees did not know the evacuation routes. These results have enabled improvement of the recent evacuation model. To obtain satisfactory results, the input parameter should not be constant and adjusted using only questionnaire surveys. Both simulation and footage reveal a problem that Indonesians did not evacuate immediately upon feeling the ground motions, and many people who responded promptly did not successfully complete evacuation. This is a pilot research on evacuation start in Indonesia, thus, more studies are required for tsunami evacuation behaviors. This study provides insights into the behaviors of Indonesians during disaster evacuation and might help determine proper countermeasures.