About flood inundation assumption area of Kumamoto
About flood inundation assumption area
Flood inundation assumption is in we find smooth at the time of flood and quick evacuation about river which Kumamoto appointed in water level common knowledge river or to prevent the inundation
Area that is assumed the inundation by the rain that is assumed to plan reduction of damage caused by ri flood when the river concerned overflows as flood inundation assumption area
Based on this flood inundation assumption area figure, hazard map which listed information of correspondence at the time of disaster or position of evacuation site concretely in the municipalities is making
About flood inundation assumption area (assumption maximum size)
In late years outbreak frequency of strong rain increases in each places of the whole country for heavy rain and short time, and localization of heavy rain is tough, and receive background doing, and in May, 2015 Flood Control Law with revision
From "the rain of plan scale" conventional by the rain to become premise by this revision in Kumamoto "the largest rain (thing more than plan scale) that can assume"
We switch to this and are making "flood inundation assumption area figure" (assumption maximum size).
Contents of flood inundation assumption area and point to keep in mind
When river overflows, flood inundation assumption is assumed by the assumed rain (assumption maximum size) when area where the inundation is assumed is flooded
We sought the depth of the water by simulation.
Area that is not appointed in this inundation assumption area as we still less consider the flooding of faction river, the rain, high tide more than assumptions, the flooding with inland waters
Case that the inundation produces even if we put in this and the assumed depth of the water may be different from real flood depth.
Type of flood inundation assumption area figure
About flood inundation assumption area figure announcing after December 21, 2018, it becomes five kinds of following things.
(1) Flood inundation assumption area figure (assumption maximum size)
The inundation range that is assumed by the largest rain assumed by the rain that actually fell in the area in the past when dike collapses and flood depth
(2) Flood inundation assumption area figure (plan scale)
When dike collapses by the rain to aim for in the future of river maintenance, we display the assumed inundation range and flood depth
(3) Flood inundation assumption area figure (the inundation duration)
After the flooding arrival, we display the time elapsed before it is less than the flood depth after it reached constant flood depth (e.g., 0.5m)
(4) House collapse the flooding assumption area figure (the flooding style)
Area with fear of house collapse is displayed by the flooding style from river
(5) House collapse the flooding assumption area figure (the bank of a river erosion)
By outflow of basic part caused by erosion of the bank of a river, we display area with fear of house collapse
About designation of flood inundation assumption area in water level common knowledge river which Kumamoto manages
About flood inundation assumption area by assumption maximum size, we appointed all 67 rivers targeting at water level common knowledge rivers in the prefecture in March, 2020.
■River which we appoint in flood inundation assumption area after flood prevention law revision in May, 2015
(in the inundation assumption area figure in country direct control river in Kumamoto)
○Shirakawa, the Midori River water system (external link) ○The Kikuchi River water system (external link)
○The Kuma River water system (external link) ○The Chikugo River water system (external link)
While, in Kumamoto, carrying out hardware measures steadily sequentially, tori of genwazawai by soft measures such as hazard map making support to the municipalities
We will push forward composing type.