Oita Prefecture misdelivered information on river flooding, system has not been restored for over a month
In November 2021, there was a problem in Oita Prefecture where incorrect information about river flooding was distributed. A total of 6 emails were mistakenly sent 3 times to a total of about 5,500 addresses. The cause of the misdelivery is believed to be thermal runaway due to a failure of the server's cooling fan. However, as of December 22, the details have not been clarified, and the server has not been replaced. Oita Prefecture is required to implement thorough crisis management and review system operations.
"Today, at 06:10, the water level of the registered river exceeded the evacuation judgment water level. If you live nearby, please pay attention to the information announced by the municipalities in the future.
On November 8, 2021, three emails were sent to residents of Oita Prefecture informing them of the evacuation information. It is a warning that the water level of the river is rising and the need for evacuation is increasing, but in reality the situation was not enough to call attention. Shinichi Yoshima, Oita Prefectural River Division's disaster prevention coordinator, apologized for sending the wrong information, saying, "I apologize for causing trouble to the citizens of the prefecture." The cause seems to be a system malfunction, but it is an unusual situation that it has not been restored even as of December 22, more than a month later.
Photo by Oita Prefectural Office: Nikkei Crosstech [Click image to enlarge]Misdelivery 3 times due to delay in grasping situation
Wrong e-mail delivered at 6:10 am on November 8th happened to There are 81 water level gauges and 89 rain gauges installed on rivers in Oita Prefecture. The water level is measured every 10 minutes, and the results are transferred to the "Oita Prefecture River and Sabo Information System" via government radio. The system consists of 11 servers and is responsible for processing such as data transmission instructions to water level gauges, reception of measurement results and calculations based on them, and data transfer to other systems. When the water level exceeds a certain standard, the data is transferred to the "Oita Prefecture Disaster Prevention Information System" and "prefectural safety and security emails" are created to convey disaster information. It is designed to be sent from Oita Prefecture to the citizens of the prefecture.
Table Background to Oita Prefecture's "River Sabo Information System" erroneous information distribution Occurrence of erroneous information distribution due to server hardware failure[Click image to enlarge]
However, as mentioned at the beginning, the water level was not high enough to call attention, and the wrong information was sent. A total of about 5,500 emails have been sent, including mobile phone emails registered in the prefecture's safety and security emails. Incorrect information was also posted on Facebook and Twitter, which are SNSs (exchange sites) linked to the system.
According to the water level risk standard set by the government, the evacuation judgment water level announced this time is positioned as "risk level 3". The highest standard indicating the occurrence of flooding is "risk level 5", and risk level 3 means that you are in a situation where you can never let your guard down. At the same time, two e-mails were sent notifying that the water level of other rivers and bridges was at risk of flooding, which corresponds to a danger level of 2.
This email was also received by the staff of the Oita Prefecture River Division. Although it had been raining since the morning of November 8, it was not heavy enough to force a decision to evacuate. An employee of the Oita Prefectural River Division, who felt something was wrong, checked the image of the river's surveillance camera, which was separate from the water level gauge, but the water level had not risen. I suspected that the water level might have risen by chance at the time of high tide, so I investigated, but it was not the time of high tide.
According to the Oita Prefecture River Division, it is possible that incorrect data may be measured in rare cases. This is because water level gauges measure the time it takes for radio waves emitted toward the water surface of a river to return, so they may be read when something obstructs them or when the water level rises temporarily. Since there have been no major system failures in the past, we decided to wait and see.
However, the misdelivery continued after that. Two emails were delivered at 8:30 am, and the target rivers (bridges) were the same as the first, such as "Suehiro River (Kuromaru Bridge) Usuki City Suehiro". After confirming the image with the surveillance camera, the water level was not at a level that required an evacuation decision. At 9:05 a.m., the Oita Prefectural River Division detected a problem with the system and sent out information to the effect that the information was incorrect. At the same time, we started investigating the cause through the company that builds and maintains the system.
At 9:50 am during the investigation, another email was delivered by mistake. The reason why the email was sent even though I was aware of the problem was that I prioritized investigating what was happening and postponed the task of stopping the email. At 10:15 a.m., the Oita Prefectural River Division sent out information to the effect that it was an error again.