Approaches to post-tsunami coastal reconstruction: Comparisons across Indonesia, Thailand, and Japan

Natural hazards pose significant challenges to affected communities worldwide, yet there remains a lack of comprehensive studies comparing recovery efforts across different countries and cultures. This study addresses the gap by investigating the impact of three devastating tsunami events on four distinct locations: Banda Aceh (Sumatra, Indonesia) and Southern Thailand, both affected by the 2004 Indian Ocean Tsunami, the 20th anniversary of which provided the initial motivation for the study; the Tohoku region of Japan, affected by the 2011 Great East Japan Earthquake and Tsunami; and Palu Bay (Sulawesi, Indonesia) affected by the Palu-Central Sulawesi Earthquake and consequent triple disaster. Data for this research was gathered from recovery missions led by the UK Earthquake Engineering Field Investigation Team (EEFIT), working in collaboration with local partners (Tsunami and Disaster Mitigation Research Centre, Tadulako University, Mahidol University and the Asian Institute of Technology). Additional material was provided by the International Research Institute of Disaster Science (IRIDeS) at Tohoku University. This paper evaluates recovery in terms of spatial planning, the development of design codes, evacuation planning, and the reconstruction development of coastal and port structures. A companion paper considers post-disaster recovery of buildings and other structures in Indonesia. Key findings include a variety of responses to planning enforcement in exclusion zones, a reliance on US tsunami codes for building code development rather than the comprehensive Japanese codes, diverse behavioural responses to the use of vertical evacuation structures, and some similarities in the use of multi-layered protection from tsunamis, inspired by Japanese approaches. The investigation provides insights into recovery and reconstruction efforts for: (i) the affected regions where agencies can compare and contrast their approaches with others, (ii) agencies and communities in similarly-affected locations in other parts of the world, and (iii) those at risk of future tsunami inundation. • Planning enforcement in exclusion zones in Indonesia not as strict as in Japan. • Influence of US rather than Japanese design codes in Indonesia and Thailand. • With lack of preparedness, tourists are vulnerable in the Thailand inundation zone. • Contrasting local acceptance of vertical evacuation structures across the 3 countries. • Japanese multilayered defence approaches influencing Indonesian coastal planning.