In exploring the relationship between ground-level road damage ratios and tsunami inundation depths following the 2011 Pacific Coast Tohoku earthquake in Japan, we focused on road damage components, excluding elevated roads, bridges, and tunnels. The damage ratio is defined as the number of damage incidents per kilometer. We used the damage dataset compiled by the Japanese Ministry of Land, Infrastructure and Transport. We propose four fragility function zones for ground-level roads based on differences in topographical features. We studied these zones based on numerical simulation results of tsunami propagation.

This article verifies the applicability of an assessment method on flood risk reduction, combining and assessing hazard control measures and exposure reduction measures together. The method develops collated flood risk curves and uses limited data, so it is an approach which can be readily applied in developing countries, where an understanding of flood risk reduction measures are become increasingly important. The method was proposed as a result of studies conducted by the National Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure, Transport and Tourism, Japan. When applying the method to a river improvement and relocation scheme with land mounding in Mindanao, the Philippines, the advantages and limitations of the method are considered.