Overtopping of coastal structures by tsunami waves

Following the 2011 Tohoku Earthquake and Tsunami, Japanese tsunami protection guidelines stipulate that coastal defences should ensure that settlements are shielded from the coastal inundation that would result from Level 1 tsunami events (with return periods in the order of about 100 years). However, the overtopping mechanism and leeward...

Performance of Models for Flash Flood Warning and Hazard Assessment: The 2015 Kali Gandaki Landslide Dam Breach in Nepal

The 2015 magnitude 7.8 Gorkha earthquake and its aftershocks weakened mountain slopes in Nepal. Co- and postseismic landsliding and the formation of landslide-dammed lakes along steeply dissected valleys were widespread, among them a landslide that dammed the Kali Gandaki River. Overtopping of the landslide dam resulted in a flash flood...

Factors responsible for the limited inland extent of sand deposits on Leyte Island during 2013 Typhoon Haiyan

Previous geological studies suggest that the maximum inland extent of storm-induced sand deposits is shorter, but their thickness is larger, than those of tsunami-induced sand deposits. However, factors that determine the maximum extent and thickness of storm deposits are still uncertain. We conducted numerical simulations of storm surge, waves,...

Development of fragility curves for railway embankment and ballast scour due to overtopping flood flow

Fragility curves evaluating a risk of railway embankment fill and track ballast scour were developed. To develop fragility curves, two well-documented events of singletrack railway washout during floods in Japan were investigated. Type of damage to the railway was categorized into no damage, ballast scour, and embankment scour, in order of...

Improvement of tsunami countermeasures based on lessons from the 2011 great east Japan earthquake and tsunami: situation after five years

The 2011 Great East Japan Tsunami exposed many hidden weaknesses in Japan’s tsunami countermeasures. Since then, many improvements have been made in both structural measures (numerical simulations, coastal defense structures, building damage assessment and control forests) and nonstructural measures (warning/observation and evacuation). This...