Chapter 23 - Long-term tsunami risk considering time-dependent earthquake hazard and nonstationary sea-level rise

Abstract

A nonstationary tsunami risk model facilitates the development of long-term risk management strategies for coastal communities. The model should account for time-dependent earthquake occurrence, variable tidal level, and future projections of relative sea-level rise, in addition to the inherent uncertainty associated with future tsunami scenarios. This chapter presents a tsunami risk model by focusing on the District of Tofino, British Columbia, Canada, which is directly exposed to megathrust earthquakes from the Cascadia subduction zone. High-resolution topography and high-quality exposure data are incorporated to evaluate tsunami economic loss to buildings in Tofino accurately. The results are expressed as tsunami risk curves for different elapsed times since the last major event and different sea-level conditions. Variable tidal levels have noticeable effects on the tsunami risk curves, while the influence of relative sea-level rise becomes increasingly more significant with time.