PROGRAM: 2-8

Title:

Abstract:

Actual disaster data is important for future risk assessment and disaster planning and management. The data can be obtained from field surveys right after the disasters. However, quality level of such risk assessment tools that will be further developed strongly depends on quality of the data from field surveys. This abstract presents the quality of an example among the tsunami risk assessment tools, namely fragility functions that reflects the quality of the disaster data. Tsunami fragility functions are defined as empirical relationships between vulnerability (i.e. damage probability) and tsunami hazard (i.e. flow depth). The 2004 Indian Ocean tsunami and the 2011 Great East Japan tsunami are two good examples for a comparison. The 2004 tsunami affected many Southeast and South Asian countries. Large numbers of buildings in Thailand and Indonesia were totally destroyed or damaged. There was a limitation due to number of surveyed damaged buildings (some hundreds or thousands) as well as detail information of each building. Therefore, the fragility functions (i.e. for Thailand) were developed using remote sensing technology to interpret building damage. Nevertheless, the damage could be only interpreted as a building was washed away or not using roofs as judgement criteria. As results, the developed fragility functions for Thailand can only explain building damage characteristics for only one type of damage where building types were also not possible to be verified from the satellite images (Suppasri et al., 2011). On the other hand, Japanese government put large effort on field survey of damaged buildings from the 2011 tsunami. The database has more than 200,000 buildings with detailed information such as tsunami flow depth, building materials, number of stories, building functions and construction year (Suppasri et al., 2013). These kinds of information allow the detailed fragility functions for the mentioned categories and further detailed risk assessment became possible. Therefore, it is very important to promote developing such standard or guideline for collecting high-quality disaster survey data in ASEAN countries.

Acknowledgements:

This study was funded by JSPS Bilateral Joint Research Projects “Proposing new building design guideline for Thailand based on building damage and seismic and tsunami fragility functions - Lessons from recent earthquakes and tsunamis in Japan and Thailand -"(grant no. 170000941) and JSPS Grant-in-Aid for Young Scientists (B) "Applying developed fragility functions for the Global Tsunami Model (GTM)" (grant no. 16K16371).

References:

Suppasri, A., Mas, E., Charvet, I., Gunasekera, R., Imai, K., Fukutani, Y., Abe, Y. & Imamura, F. (2013), Building damage characteristics based on surveyed data and fragility curves of the 2011 Great East Japan tsunami, Natural Hazards, 66 (2), 319-341.

Suppasri, A., Koshimura, S. & Imamura, F. (2011) Developing tsunami fragility curves based on the satellite remote sensing and the numerical modeling of the 2004 Indian Ocean tsunami in Thailand, Natural Hazards and Earth System Sciences, 11(1), 173-189.