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Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

Recent Storm Surge and Wave Disastersand Actions on Coastal Defense and Port Facility Design in Japan
Hiroyasu Kawai
Port and Airport Research InstituteYokosuka, Kanagawa, Japan

ABSTRACTThis paper first reviews (1) the storm surge and wave disasters in thecoastal and port areas of Osaka Bay and Tokyo Bay in Japan in 2018 and2019, respectively and (2) two intensity levels of typhoons for coastal
defense design and evacuation planning. Then, the paper summarizes
their technical issues, such as, the radius of maximum wind speed inworst-case storm surge and wave-overtopping flood simulations. Finally,
the paper presents climate change related issues, such as: (1) past meansea level, typhoon, wave, and storm surge trends, and (2) future climatechange adaptation.

KEY WORDS: Typhoon; storm surge; wave; radius of maximum
wind speed; coastal defense; port facility; climate change adaptation.

INTRODUCTIONFig. 1 shows that Japan has many cities of more than million people on
low plains that extend from the coast of very enclosed bays. These bays
are several tens of kilometers from the mouth to the head and have maximum depths of a few tens of meters. They are usually calm but meetstorm surges and high waves during typhoon events. In addition, groundwater pumping has caused some parts of the land to sink below the mean
monthly-highest water level (hereinafter, HWL) and increased the riskof flooding. The ports on the coast play a core role in international shipping and the country’s economy.

for 120 days, eventually claiming 5,000 lives. The flood carried muchlauan logs from lumberyards in the port and destroyed many buildings.
The event prompted the national and local governments to start building
massive coastal defense in the 1960s on the coast of Tokyo Bay, Ise Bay,and Osaka Bay for the storm surge of the Vera-class design typhoon (Kawai, 2019).
Since then, no great storm surge disaster (loss of 50 lives; significantly
lower than the 1959 event) occurred in the country, despite many rainfall-induced disasters. This could be due to the construction of long massive coastal defense; however, no severe typhoon like Vera reoccurred
near the cities. On the other hand, many aged coastal defense facilities
need careful inspection and repair. The 2018 Typhoon Jebi and the 2019Typhoon Faxai caused storm surge and wave disasters on the coast of
Osaka Bay and Tokyo Bay, respectively (Mori et al., 2019a; Kawai et al.,2020b; Shimozono et al, 2020). With the Intergovernmental Panel on
Climate Change (IPCC) warning of future mean sea level (hereinafter,MSL) rise and typhoon intensification (IPCC, 2019), there is a growinginterest in designing facilities for climate change.
38
Sea of Japan
Major coastal cities
a: Tokyo, b: Kawasaki,
c: Yokohama, d: Nagoya,Honshu Is.
e: Osaka, f: Kobe,
36 g: Hiroshima, h: Fukuoka
abcd940 hPafe
Tokyo BaygIse Bay
Osaka Bay34
Shikoku Is.
h929 hPa
912 hPa
Pacific Ocean

Two major storm surge disasters occurred in the 1950s. The 1953 Typhoon Tess crossed the mouth of Ise Bay and triggered storm surge
flooding along the southern and eastern coast. This event led to the enactment of the 1956 Coast Act, which requests each prefectural governor
to protect coastal areas from tsunamis, storm surges, and high waves.
The 1959 Typhoon Vera caused a landfall on Honshu Island (centralpressure: 929 hPa) and passed by Ise Bay (940 hPa), generated a storm
surge in the bay, recorded 3.5 m at Nagoya Port, causing the collapse of
the coastal dike and flooding over the area of 30 km inlands that lasted

Kyushu Is.

32
i30128

B911 hPa
A130
132

C134

D136

Major typhoons
A: Muroto, 1936
B: Makurazaki, 1945
C: Tess, 1953
D: Vera, 1959
138
140
142

Figure 1. Major coastal cities and typhoon tracks in Japan.

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