With record rains comes misery

Typhoon No. 12 (Talas) has brought heavy rains mainly in western Japan. As of the night of Sept. 5, 37 people had died and 54 others were missing. Among the typhoons that hit Japan since 1989, when the Heisei Era started, the latest one caused the second largest number of deaths and missing victims, following Typhoon No. 23 of 2004, which caused 98 people either to die or to go missing.

Hardest hit by Typhoon No. 12 was the Kii Peninsula of Honshu, where unprecedented rainfalls killed some 30 people and caused some 50 others to become missing.

The damage from the typhoon has become a big domestic task for the Noda administration to tackle. It must do its best to help rescue people trapped in debris or in earth and sand or left in isolated communities, find missing people, and restore damaged roads, bridges and other infrastructure.

The Mie, Tottori, Nara and Wakayama prefectural governments have decided to apply the Disaster Relief Law to 20 municipalities. Under the law, the central and prefectural governments shoulder the cost of running shelters for evacuees 50-50.

A high-pressure air mass that stood in the typhoon’s way kept it from moving fast. It moved north at almost a snail’s pace of 10 kph to 15 kph, dumping lots of rain for a long time. The typhoon landed in Kochi Prefecture of Shikoku on Sept. 3. After crossing Shikoku and the Inland Sea and landing in the southern part of Okayama Prefecture of Chugoku in western Honshu, it reached the Sea of Japan on Sept. 4.

The Meteorological Agency analyzed the mechanism which brought the extremely heavy downpour on the Kii Peninsula the following way:

Its storm area was wide, with the maximum diameter reaching about 400 km. Because its speed was slow, cumulonimbus clouds around it covered the peninsula for a long time. In addition, as the typhoon moved north, moist air continued flowing into the peninsula — from east-southeast on Sept. 2, from southeast on Sept. 3 and from south on Sept. 4.

The moist air hit mountains 1,500 to 1,900 meters high in the central part of the peninsula and turned into updrafts, continuously forming rain clouds.

The cities of Shingu, Wakayama Prefecture, and Kumano, Mie Prefecture, respectively, registered an hourly rainfall of 132.5 millimeters and 101.5 millimeters — both record rainfalls.

In the village of Kamikitayama, Nara Prefecture, the rainfall which started on the evening of Aug. 30 amounted to 1,808.5 millimeters. On the evening of Sept. 4, AMeDAS (the Automatic Meteorological Data Acquisition System) in the village stopped transmitting data.

The heavy rainfalls caused flooding of rivers and landslides, which evacuees and local municipality government workers said they had not experienced before.

Kumano Nachi Shrine in the town of Nachi Katsuura, Wakayama Prefecture, on the Kumano Kodo “World Heritage” pilgrimage routes, was partially buried by earth and sand. Part of the roof of the Kinpusen Temple in the town of Yoshino, Nara Prefecture, which is a national treasure, was partly damaged.

At one time, more than 400,000 people, including some 300,000 in Okayama Prefecture and some 100,000 in the city of Himeji, Hyogo Prefecture, in western Honshu, were ordered or recommended to evacuate.

Some municipalities apparently failed to issue evacuation orders or recommendations, contributing to the large number of deaths and people who became missing.

In the city of Tanabe, Wakayama Prefecture, earth and sand hit five houses. One died and five others went missing.

In the village of Totsugawa, Nara Prefecture, seven people went missing when their houses were washed away. In the city of Gojo, Nara Prefecture, after about 10 houses were washed away and one person died, an unspecified number of people were missing.

It is reported that no evacuation order had been issued in these municipalities. A worker of the Gojo city government said that since local residents ordinarily had a keen sense of concern about natural disasters, the city government might have trusted their judgment too much. This report backs the need to study what actions municipal governments concerned took, what went wrong and what eventually happened.

It will be important for municipal governments across the nation to prepare and distribute hazard maps and tell local residents in advance what routes and what shelter facilities to use when heavy rains hit their areas.

In 2005, the Cabinet Office issued a guideline concerning issuance of evacuation orders by municipal governments when natural disasters happen. But as of November 2009, only 46 percent of the nation’s municipal governments had their own standards for issuing evacuation orders when floods are feared to occur. The corresponding rate for landslides was 41.4 percent. Municipal governments need to consider in detail what preparations they should make when floods and landslides are likely to occur.

Although Typhoon No. 12 turned into a tropical low-pressure area in the Sea of Japan, heavy rains were hitting Hokkaido and Tohoku on Tuesday. On the Kii Peninsula, rainfalls had made the ground soft. Utmost caution needs to be taken to prepare for secondary disasters such as landslides in areas soaked with rainwater and floods that may occur when earth and sand clogging rivers break up.