- Glossary -

10 minutes

The amount of rainfall in the past 10 minutes of the current time (1:00, 1:10, 1:20, 1:30...). For e.g, current time: 2:15, rainfall displayed: 2:00 - 2:10; current time: 2:21, rainfall displayed: 2:10 - 2:20...

1-hour rainfall

The amount of rainfall in the past 1 hour of the current time (1:00, 2:00, 3:00...). For e.g, current time: 2:15 pm, rainfall displayed: 1:00 pm - 2:00 pm.

Displayed water level

Approximation of water level of general river

　Caution

　40 - 60% of the height of the revetment depending on the width of the river

　Alert

　70 - 90% of the height of the revetment depending on the width of the river

Flood alert

The information to be announced when the water level of a river reaches the flood alert river

Flood danger

The information to be announced when the water level of a river reaches the flood danger level

Flood inundation

The information to be announced when the flood has occurred

Flood warning

The information to be announced when the water level of the river reaches a flood alarming level

No fluctuation

A condition in which the water level has risen less than 1 cm compared to 1 minute ago

Stand-by water level for Flood Defense

The water level that alerts flood defense committee to stand by for flood fighting activities

Top of the dike

The top edge of the levee or revetment

Water level fall

A condition in which the water level has fallen 1 cm or more compared to 1 minute ago

Water level rise

A condition in which the water level has risen 1 cm or more compared to 1 minute ago