2024 Volume 80 Issue 17 Article ID: 24-17072
In response to climate change, there is a crucial need to reassess tsunami water level design parameters within Japan. This study explores how sea level rise influenced by climate change affects tsunami heights along the coast of Hokkaido. Our analysis based on tsunami simulations with varied initial water levels found that higher initial levels significantly increase tsunami heights, particularly in bay-like topographies. While the height of the initial tsunami wave remains unchanged, significant variations due to initial water levels become noticeable from the second wave onward, mainly due to bay oscillations caused by wave reflections. Additionally, the study of the tsunami water level spectrum showed that although the overall shape remains consistent, higher initial levels cause the peak period to shift towards shorter cycles, increasing peak amplitude. These findings highlight the need for a careful revision of tsunami design water levels to accommodate the impacts of climate change on the first and subsequent waves.
