Tsunami damage to ports: cataloguing damage to create fragility functions from the 2011 Tohoku event

Abstract

Abstract. Modern tsunami events have highlighted the vulnerability of port structures to these high-impact but infrequent occurrences. However, port planning rarely includes adaptation measures to address tsunami hazards. The 2011 Tohoku tsunami presented us with an opportunity to characterise the vulnerability of port industries to tsunami impacts. Here, we provide a spatial assessment and photographic interpretation of freely available data sources. Approximately 5000 port structures were assessed for damage and stored in a database. Using the newly developed damage database, tsunami damage is quantified statistically for the first time, through the development of damage fragility functions for eight common port industries. In contrast to tsunami damage fragility functions produced for buildings from an existing damage database, our fragility functions showed higher prediction accuracies (up to 75 % accuracy). Pre-tsunami earthquake damage was also assessed in this study and was found to influence overall damage assessment. The damage database and fragility functions for port industries can inform structural improvements and mitigation plans for ports against future events.

Quantifying tsunami impact on industrial facilities and production capacity in ports: An application to Sendai Port, Japan

“…Therefore, the tide level of +0.7 m is selected as the high tide level [18] in other tsunami case scenarios for hazard and risk assessment in sections 5 and 6. In a previous study [4], eight common port industries were identified in the Tohoku region based on their occupancies. The participants in this study could be classified into five of those industries as follows:…”

“…Fig. 12 shows the factory damage maps when applying structural fragility functions (Damage State 2 = Operational only after repairs) [4] to all five large tsunami scenarios. Similar to the inundation maps (Figs.…”

“…Since the 2011 Great East Japan earthquake and its subsequent tsunami, an extensive body of work has been dedicated to studying the structural damage to buildings [1,2,3] and, more recently, the structural damage to port industries [4] due to tsunami impacts. However, even when buildings remain structurally intact, industrial facilities may lose their functions due to nonstructural damage.…”

“…Until recently, few studies [4,6] have considered the vulnerability of industrial facilities to tsunami impacts. This gap in research can be due to the infrequency of large tsunami events that result in limited observations.…”

“…A post-2011 tsunami survey carried out by the Tohoku Regional Development Bureau [8] found only 13% of the 233 companies in ports along the eastern coastline of the Tohoku region to be unaffected by the earthquake and tsunami. Various types of industrial facilities are located in the ports along the coast of Tohoku region [8] and their recovery rates varied between industries and events [4]. Therefore, case studies from the Tohoku region provides an excellent opportunity to quantify the vulnerability of sector-specific operations to tsunami impacts.…”