2017 Northern Kyushu floods

Collapsed building steel frame in Asakura

Damage in Asakura

The 2017 Northern Kyushu floods (Japanese: 平成29年7月九州北部豪雨^[1]) was a disaster caused by a cloudburst that occurred in northern Kyushu in July 2017.^[2] On July 5, a heavy torrential rain, followed by a debris flow, hit Asakura, Fukuoka Prefecture and Hita, Oita Prefecture.^[3] According to an official of the Japan Fire and Disaster Management Agency, 36 people died, with 21 injured.

Overview[]

2017-07-05 13:00-21:00 precipitation in Kyushu

JMA Weather chart-July 4th to 7th 2017

Tropical Storm Nanmadol dropped torrential rainfall across Kyushu, resulting in landslides, although the Fukuoka and Ōita Prefectures were the hardest hit. The city of Asakura, Fukuoka experienced a one-day rainfall surpassing the city's average total for July by 50%, with a rainfall of 500 mm (20 in) recorded within a 12-hour period on July 5.^[4] Landslides were recorded in 44 different locations and flooding in 38 locations, and from this, more than 2,600 homes were destroyed. In total, 42 people died from Nanmadol due to drowning from flash flooding or due to landslides.^[5] Total damages was estimated to have toppled to ¥190 billion (US$1.68 billion).

Tropical Storm Nanmadol[]

Tropical Storm Nanmadol affecting southern Japan on July 4

The JMA issued a heavy rain warning for Shimane Prefecture and neighboring areas, in which the government had urged 20,000 residents to evacuate.^[6] On July 3, the Sasebo City Emergency Management Bureau activated a total of 30 emergency shelters.^[7] The government dispatched a total of 12,000 rescuers, including police officers, firefighters and the Self-Defense Forces troops, in preparation for post-storm relief.^[8] On July 10, the Kyushu Railway Company began a bus service to aid residents trapped in some areas along the currently suspended Kyudai Main Line; this included areas between Ukiha Station in Fukuoka Prefecture and Hita Station, Ōita Prefecture, where an iron bridge spanning a river was washed away by floodwaters. Due to the threat of further landslides, the West Nippon Expressway Company extended a closure of the Ōita Expressway.^[9] Trees with trunks of 50–60 cm (19.7–23.6 in) were washed away, blocking the water stream further and exacerbating floods. Therefore, on July 11, Forestry Minister Yuji Yamamoto pledged to set up a task force to remove driftwood. Meanwhile, an official at the University of Hyogo warned other municipalities of potential damage caused by fallen trees.^[10]

Tropical Storm Nanmadol track

Peak windspeeds of 150 km/h (93 mph) were recorded in Nagasaki upon landfall, including a 162 km/h (101 mph) wind gust in the Shikoku town of Muroto just after 05:30 UTC.^[11][12] Strong winds overturned vehicles, collapsed scaffolding, and left 68,500 homes without power in Nagasaki and Kumamoto prefectures; other blackouts occurred in the prefectures of Ōita, Miyazaki and Kagoshima.^[12][13] Around 3,000 airline passengers were affected by the grounding and cancellation of at least 47 flights. Heavy rains and strong winds disrupted numerous train services including the iconic Shinkansen, between Hakata and Kagoshima-Chuo in Kyushu.^[12][13] Evacuation advisories were issued to at least 20,000 residents due to fears of possible flooding and landslides, especially in the Niigata, Toyama and Nagano prefectures that had experienced rainfall accumulations of up to 300 mm (12 in) in the preceding hours.^[13] In Hamada, Shimane, over 80 mm (3.1 in) fell in an hour.^[14][6]

Map of satellite-estimated rains across Japan after the passage of Tropical Storm Nanmadol

At least three people were injured during the storm—a young boy's hand was injured when a school window broke in the city of Kumamoto, and two adults in Ōita prefecture sustained injuries from falls as a result of the strong winds.^[13][15] About 180 people took shelter at a junior high school gymnasium in Asakura.^[8] Within the prefecture, 130 mm (5.1 in) of rain fell in an hour, greatly contributing to a 24-hour rainfall total of 545 mm (21.5 in).^[16] A later report showed that the prefecture experienced a total accumulated rainfall of 632.5 mm (24.90 in).^[17] The city of Hita, Ōita also experienced extreme rainfall, with accumulations of 400 mm (16 in).^[18] However the prefecture of Fukuoka experienced an incredible amount of 774 mm (30.5 in) of rain within the course of nine hours on July 5.^[19] Due to the risk of landslides, an evacuation order which covered 316 people from 115 households was issued in the Haki District of Asakura, due to high risk of landslides. Throughout the Fukuoka and Ōita Prefectures, 1,724 people evacuated.^[9] More than 2,600 homes were destroyed by Nanmadol around the Fukuoka, Oita, and the Hiroshima prefectures,^[20] but a later report showed a total of 4,458 buildings damaged.^[21] Nearly a week after the flooding had begun, some roads were already reopened over in some communities in the Fukuoka Prefecture.^[10] During July 12, the Japanese Prime Minister Shinzō Abe canceled a trip to Estonia for a European tour and instead visited devastated places over in the Kyushu region to view the damage and console residents. He also promised that the government would take action and do everything possible to help rebuild.^[22][23]

A total of 42 people have been confirmed dead due to torrential rains which caused landslides and flooding, particularly in Kyushu,^[20][24] where two still remained missing and leaving 39 people injured.^[21][17] Total damages in Japan were amounted to be ¥190 billion (US$1.68 billion).^[21]

References[]

See also[]

• Tropical Storm Nanmadol (2017)