Use monuments to past disasters to better inform residents of risks

Knowing to what extent the area around one’s home or workplace is at risk from natural disasters is key to protecting lives.

In addition to checking local governments’ hazard maps, attention should be paid to monuments and old documents that record area disasters of the past.

In the Aneyoshi district of Miyako, Iwate Prefecture, there is a stone monument that was built to commemorate the devastation wrought by the 1933 huge tsunami that hit the Sanriku coast. The warning from the past, “Do not build a house below this point,” helped limit the damage caused by the 2011 Great East Japan Earthquake.

Earthquakes and tsunami can recur in cycles spanning decades or even hundreds of years. It is critical to learn from history.

An estimated 2,000 to 3,000 monuments in Japan record the memories and lessons of natural disasters. The Geospatial Information Authority of Japan created a map symbol in 2019 indicating monuments to past disasters, and the agency is in the process of putting it on maps. So far, about 1,100 monuments have been marked on maps.

The city of Ukiha, Fukuoka Prefecture, has compiled a booklet of monuments and old documents that indicate the damage caused by mudslides and other disasters in the Edo period and other disasters, and has been distributing it to residents and schools.

The booklet contains such vivid descriptions as “Most of the houses were destroyed when large stones washed in” and “The bodies were so damaged they could not be identified.”

In some cases, residents’ lack of awareness of the danger caused damage to spread.

Most of the areas where people were killed in the torrential rains in western Japan in 2018 were either in “landslide disaster caution zones” where evacuation plans for residents needed to be created, or were the subject of a survey to designate such a zone. There is a monument in the town of Saka, Hiroshima Prefecture, that tells of a torrential rain disaster in 1907.

One of the survivors of the 2018 disaster said, “If I’d known about the danger, I would have evacuated earlier.”

In many cases, places where the damage caused by disasters is recorded on monuments and in old documents overlap with warning zones on hazard maps.

It is important for each and every resident to confirm the features of their community and raise their awareness of disaster prevention. The number of people who would say “I didn’t know [about the risk]” must be minimized as much as possible.

An area can be designated as a “special disaster warning zone” if there is a risk of significant damage from landslides. If so designated, the area is subject to development restrictions and relocation advisories.

In some prefectures, the designation of landslide disaster caution zones and special disaster warning zones has been delayed due to a lack of manpower and opposition from residents who are concerned about a decline in real estate values.

If a disaster were to occur, it would be irreparable. Each municipality must give top priority to human life and thoroughly inspect and inform the public about dangerous zones.

— The original Japanese article appeared in The Yomiuri Shimbun on Dec. 5, 2021.