Risk estimation of the disaster waste generated by both ground motion and tsunami due to the anticipated Nankai Trough earthquake

Abstract

The amount of disaster waste is one of the most important performance indicators in quantifying the resilience of a community. In fact, disaster waste can have significant negative impacts on the environment in affected regions and hinder the postdisaster recovery process. Appropriate disaster waste management should be developed in Japan before the occurrence of the Nankai Trough earthquake. It is expected that the seismic and tsunami intensities caused by the anticipated Nankai Trough earthquake will be substantially larger than those caused by the 2011 Great East Japan earthquake. In this paper, a risk-based methodology is presented for estimating the amount of disaster waste generated by both the ground motions and the tsunami due to the anticipated Nankai Trough earthquake. First, Monte Carlo simulation-based probabilistic hazard analyses are performed to obtain seismic and tsunami hazard curves considering the uncertainty associated with fault movement along the Nankai Trough. Structural damage data associated with past earthquakes are used to develop seismic and tsunami fragility curves. The amount of disaster waste generated from a single structure is defined as the generation unit and is determined based on past disasters. Finally, with the aid of a geographic information system, the risk of disaster waste can be estimated using the hazard and fragility curves and the generation units. As an illustrative example, the risk curves and expected values associated with disaster waste in Mie Prefecture, Japan, are estimated based on the proposed framework.

Investigating the Effects of Climate Change on Structural Actions

“…The tsunami hazard curve increases when considering the effects of sea-level rise. Depending on the exposure of the analyzed infrastructures, the potential impact of small tsunamis should not be underestimated since it could generate a considerable amount of economic loss, casualties, and disaster waste that could impede the recovery process (Akiyama et al, 2020;Ishibashi et al, 2021). Moreover, although the results presented in this study are demonstrated with an emphasis on the year 2100, the time frame for decision-making has to be justified depending on stakeholder interests.…”

Life‐cycle risk assessment of building portfolios subjected to tsunamis under non‐stationary sea‐level rise based on a compound renewal process

“…Although many studies have focused on developing methodologies for life-cycle risk assessments involving different infrastructure systems influenced by tsunami hazards, 7,11,32 the effects of uncertain sea-level rise have not yet been considered in their computations. Due to non-stationary sea-level rise effects, the risk of infrastructure under tsunami hazards is not identically distributed and becomes time-variant.…”

“…65 The average stress drop is truncated at 3.0 MPa to restrain unphysical earthquake occurrences. 11 Conversely, the rake angle is assumed to follow a normal distribution with a mean and standard deviation of 0.0 • and 10.0 • , respectively. The average stress drop is then converted to slip dislocation according to the equation given by the Headquarters for Earthquake Research Promotion 66 as follows:…”

“…[6][7][8] The anticipated Nankai Trough earthquakes are projected to cause an economic loss of up to approximately 171.6 trillion JPY (1.56 trillion USD) 9,10 and generate excessive disaster debris that requires more than 20 years to fully remove in several regions of Japan. 11 In addition, progressive sea-level rise effects are projected to exacerbate future tsunami disasters. 12,13 Therefore, tsunami risk assessments of infrastructure considering sea-level rise effects are needed to reliably estimate the magnitude of disasters in coastal communities and accelerate disaster preparedness.…”

“…Furthermore, the recurring Nankai‐Tonankai Trough megathrust subduction has historically triggered earthquakes with M w values greater than 8.0 and generated massive tsunamis that have eradicated coastal infrastructure in the southwestern region of Japan 6–8 . The anticipated Nankai Trough earthquakes are projected to cause an economic loss of up to approximately 171.6 trillion JPY (1.56 trillion USD) 9,10 and generate excessive disaster debris that requires more than 20 years to fully remove in several regions of Japan 11 . In addition, progressive sea‐level rise effects are projected to exacerbate future tsunami disasters 12,13 .…”