Further descriptions of terms

Information on amount of rainfall

[Rainfall in 10 minutes]

It is rainfall in the most recent 10 minutes.

[Rainfall in 60 minutes]

It is rainfall in the most recent 60 minutes (1 hour).
You can confirm the strength of rain and the way rain falls on the website of The Japan Meteorological Agency. 
*The website of The Japan Meteorological Agency “The strength of rain and the way rain falls”
(http://www.jma.go.jp/jma/kishou/know/yougo_hp/amehyo.html)

[Effective rainfall]

Effective rainfall is the standard rainfall calculating the effect of rainfall in the past by decreasing it over time.
This city’s system uses the 72 hours half-value period.

[Cumulative rainfall]

“Cumulative rainfall” is a total amount of rainfall from starting raining to that time.
Cumulative rainfall will be reset after no rain continues for a certain period of time. When a rainfall is detected after that, it is regarded as new rain (starting raining).

State of rain clouds

[High-resolution Precipitation Nowcasts]

High-resolution Precipitation Nowcasts provide short-range precipitation intensity predictions with a spatial resolution of 250 m. They are derived from weather radar data by The Japan Meteorological Agency.

Standard water level

[Stand-by water level for flood fighting corps]

It is a water level set to flood prevention warning rivers and it is also the standard water level which flood prevention teams standby against floods and storm surges and prepare for flood prevention activities.  
It corresponds to a water level of notify, written in the provisions of Article 12 of the Flood Prevention Act.
The flood control warning rivers of this city are as follows.
The flood control warning river)
*The river managed by the nation: Ootagawa River, Misasagawa River, Nenotanigawa River, Kyuootagawa River, Motoyasugawa River, Tenmagawa River
*The river managed by the prefecture : Yahatagawa River, Yasukawa River, Misasagawa River, Nenotanigawa River, Minochigawa River, Senogawa River, Enkougawa River, Kyoubashigawa River

[Flood watch water level]

It is a water level to be cautious about disaster occurrence due to floods and storm surges (warning water level given by the provisions of Article 12 of the Flood Prevention Act). Also, it is the standard water level which flood prevention teams etc. dispatch in the flood prevention warning rivers. 
It is essential that we pay fully attention to rise of a water level after reaching.

[Water Level Basis for Decision to Evacuate]

It is a water level to start to alert to information on overflow for residents while it becomes a reference for determination of issuing the orders of evacuation preparation and starting the evacuation for the elderly etc. by the mayor of municipality.
It is essential that we are fully vigilant against rise of a water level after reaching.

[Flood danger water level]

It is a water level to be fully cautious about disaster occurrence due to floods (emergency warning water level given by the provisions of Article 13 of the Flood Prevention Act). Also, it is the standard water level for the mayors to determine to issue evacuation warning etc., and it is a reference for residents to determine to evacuate.
It is essential that we are strictly vigilant against rise of a water level after reaching.

Tide level information

[Warning tide level]

It is the standard tide level which flood prevention teams standby against storm surges and prepare for flood prevention activities.  
It has been set T.P.2.1m in Hiroshima port designated for Hiroshima city.

[Tide Level Alert]

It is a tide level to be cautious about disaster occurrence due to storm surges while it is the standard tide level which flood prevention teams etc. dispatch.
It has been set T.P.2.5m in Hiroshima port designated for Hiroshima city.

[Astronomical tide]

Such as high tide, low tide and flood tide, neap tide, a change in tide level caused by tidal force of moon and sun is called “astronomical tide” and its tide level is called “astronomical tide level”.
If there is an observation data with good accuracy about a certain point in long term, astronomical tide level of that point can be predicted in a high accuracy.
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