Tropical Cyclones Affecting Japan Central Coast and Changing Storm Surge Hazard since 1980

Abstract

 This study investigated tidal records and landfall tropical cyclone (TC) best tracks from 1980 to 2019 to determine changes in storm surge heights in coastal regions of Central Japan, including Tokyo. The results indicate that annual mean storm surge heights have increased in the last 20 years (2000-2019) compared to those in 1980-1999, and that these changes are noteworthy, particularly in Tokyo Bay. TC wind intensity and size during landfall time frame have become stronger and larger, respectively, corresponding to increasing storm surge magnitudes from 1980 to 2019. The increased occurrence frequency of TCs with more northeastward tracks is another factor that may have contributed to the increased surge hazards around Tokyo. Additionally, a positive correlation between surge heights and a hazard index supports these statistical findings. Japan central coast will likely experience increasing numbers of extreme storm surge events in the future, if, the current increasing tendency continues.