The Jodo River in the Shinano River System No water level gauge Monitoring system is an issue on October 15 at 22:55
Interviews with prefectures and other organizations revealed that the Shinano River system river in Nagaoka City, Niigata Prefecture, which was flooded due to Typhoon No. 19, was not equipped with a water level gauge that would serve as a guide for local governments to evacuate. . In Niigata Prefecture, only 14% of the rivers have water level gauges installed, and how to monitor small rivers and tributaries is an issue.
As a result of Typhoon No. 19, Nagaoka City was flooded with water from the “Jodo River” in the Shinano River System, causing damage to 125 houses. Nagaoka City did not give evacuation advisories or instructions to the surrounding area, and it was only after the Jodo River was flooded that evacuation preparation information was issued.
Nagaoka City explained that there was no water level gauge in the Jodo River, and that the disaster prevention department in the city grasped the flooding because of a report from the residents.
The river level is one of the guidelines for local governments to provide evacuation information. According to Niigata Prefecture, the rivers in the prefecture managed by the prefecture and the country, such as the Jodo River, are the second largest in the country after 1163 and Hokkaido. Of these, 164 rivers are installed with water level gauges, accounting for only 14% of the total.
It is difficult to install water level gauges in all rivers due to financial reasons, and many tributary water levels are confirmed directly by patrols or estimated from the water levels of surrounding rivers. The challenge is how to monitor tributaries.
The water level gauge will not be installed
According to Niigata Prefecture, the water level gauges installed in 100 rivers in the prefecture are conventional types that also observe rainfall, and wireless communication facilities are required, and the installation cost is approximately 25 million yen per water level gauge. It is expensive. For this reason, it can only be installed in high-risk locations.
On the other hand, a water level meter called “crisis management type”, which has been installed since last year, can be installed for about 1 million yen, and the prefecture has sequentially installed this type of water level meter.
According to the prefecture, it was planned to install two water level gauges in the Jodo River in Nagaoka City that caused damage such as flooding on the surrounding area in the surrounding area, but it was not in time for this typhoon is.