This thesis is about the people from the Mentawai Islands (in Indonesia) in the context of disaster risk reduction. It results from a curiosity to deeply explore the tsunami hazard knowledge existing before the 2010 Mentawai tsunami occurred, and current tsunami preparedness. It also provides theoretical frameworks and key research concepts in relation to the issues. In order to understand the picture of Mentawai in the past and the present, the thesis also includes how the tsunami vulnerability progression has been formed. The progression presents from the era of solitary lives of the people, the era of destroying the traditional beliefs and tools, and up to the current era when the people live in unsafe locations. In order to obtain a full picture of the topics, a qualitative case study was designed with the consideration of how to plot and to show a number of illuminating facts.

The people’s reflections and perspectives on their tsunami hazard knowledge before the 2010 tsunami occurred and devastated the islands, and their current tsunami preparedness, were examined. There were a number of substantial facts showing how the research participants captured, shared, and internalized explicit knowledge on tsunami hazards into their tacit knowledge. These processes occurred with little support from the district government and local non-government organizations, and were further impacted by their low socio-economic and educational status. The processes of the knowledge internalization were obviously influenced by their traditional beliefs and personal perceptions. Thus, the implications of the internalization were also different when it came to anticipating tsunami waves. Subsequently, the 2010 tsunami also brought different impacts to the participants. In the context of current measures, tsunami preparedness is applied differently at various levels, even though the people have experienced the 2010 tsunami. At the individual level, the participants mostly ignore their own preparedness, although some of the participants have specific personal efficacy and protective behaviour to avoid tsunami waves. At the household level, some would most likely leave their household members to save themselves, while others would try to help their family members. At the sub-village (dusun) level, the people tend to abandon the evacuation processes. Meanwhile, at the district level, although some important documents exist for the district government to follow, tsunami preparedness measures are less prioritized.

The last parts of the study are how the local community of Mentawai can increase their capacity to encounter potential tsunamis. In the absence of modern technologies, the community has a number of traditional strategies to anticipate hazards and various opportunities to reduce their vulnerability. Developing coping capacity is essential for the people through implementing community early warning systems. These systems will provide risk knowledge, strategies to monitor the surroundings, understandable warning communication, and qualified response capability in the event of a tsunami. For the longer term, the leaders and the community need to work hand in hand to create an adaptive mechanism for living in Mentawai. This will be achieved by utilizing and reutilizing their traditional tools and strategies, and taking any opportunity to improve their livelihoods, and consequently, their coping and adaptive capacities to deal with tsunamis.