Flood Mapping Method Accounts for Sediment and Woody Debris
Overview
A technical review committee that examined methods for assessing water level rises and inundation areas caused by sediment and woody debris has compiled a draft revision of the “Guide to Preparing Flood Inundation Maps for Small Rivers.” The notice announces the handover ceremony from chair Koji Ikeuchi to Teru Morimoto, Director-General of the Water and Disaster Management Bureau, and explains media arrangements and the planned publication of the draft revision.
Key points
- The technical review committee compiled a draft revision of the “Guide to Preparing Flood Inundation Maps for Small Rivers.”
- Chair Koji Ikeuchi will hand the draft revision to Teru Morimoto, Director-General of the Water and Disaster Management Bureau.
- The draft revision is scheduled to be posted on the Ministry of Land, Infrastructure, Transport and Tourism website after the handover ceremony.
Overview
Following the January 2024 Noto Peninsula earthquake and the heavy rain disaster in the Noto Peninsula in September of the same year, the “Committee on Flood and Sediment Disaster Countermeasures in Light of the Noto Peninsula Earthquake and Heavy Rain” was established. In June 2025, the committee recommended improving and providing risk information, including introducing hazard maps that account for the effects of sediment and woody debris.
In response to the recommendations, a technical review committee examined methods needed to prepare inundation maps for small and medium-sized rivers, including ways to assess water level rises and inundation areas caused by sediment and woody debris.
Details
The committee held four rounds of discussions and compiled the draft revision. The chair is Koji Ikeuchi, Professor Emeritus at the University of Tokyo and Chairperson of the River Information Center.
The handover ceremony will take place in a meeting room within the General Affairs Division of the Water and Disaster Management Bureau on the first floor of Central Government Building No. 3. Camera filming is permitted. At around 11:15, after the ceremony, the secretariat will hold a media briefing at the same venue.
Those wishing to cover the event should apply by email and provide their name (with phonetic reading), affiliation, telephone number and email address, and details of their attendance. Send applications to hqt-drkentou【a】gxb.mlit.go.jp, replacing 【a】 with @. Personal information collected will be managed appropriately and used only for necessary purposes.