Hazard Map Proves to Be Precise in Deadly Flooded Western Japan City

July 13, 2018

Kurashiki, Okayama Pref.- The landslide and flood hazard map of the city of Kurashiki, Okayama Prefecture, western Japan, almost precisely predicted areas massively flooded by torrential rain through last weekend, but dozens of residents, mainly elderly people, died in the worst-hit Mabicho district.

"I didn't imagine such a situation," Noboru Takeuchi, 70, said. Looking out of a window on the first floor of his home in the district early in the morning on Saturday, he saw muddy water rushing in from both sides of a street. He then hurried to move items of furniture to the second floor and headed by car for a nearby elementary school designated as a shelter.

Takeuchi admitted that he knew of the hazard map, which also stipulates a course of action to be taken if an evacuation advisory or instruction is issued, but had never seen it closely. "We have to change our attitude," he said.

Takeuchi said he was monitoring television and radio information on the unfolding disaster. "But I hesitated to evacuate until I actually saw the upcoming water flows," he said.

Kurashiki Mayor Kaori Ito has said the city issued evacuation instructions at appropriate times, based on information from a local river office of the land ministry, as well as the Japan Meteorological Agency.

Nearly 30 pct, or about 1,200 hectares, of the Mabicho district was flooded after the river levees collapsed at many locations in the city. Flooded areas mostly overlapped those indicated by the hazard map, according to the Geospatial Information Authority of Japan.

Flood levels are estimated to have reached about 4.8 meters at the deepest in Mabicho, while the hazard map had warned that flood levels might rise over 5 meters.

"We need to renew our recognition of the importance of hazard maps and act with a sense of crisis in time of disaster," said Toshitaka Katada, professor of disaster social engineering at the University of Tokyo.

Katada also called for discussions on a community-based system to help elderly and other vulnerable people survive disasters. Jiji Press