Geoinformatics Unit

Preliminary Flood Mapping Following Torrential Rain in Kumamoto, Japan

July 6, 2020

On July 4, 2020, torrential rains hit Kyushu, Japan, triggering floods and landslides. The Geoinformatics Unit, RIKEN Center for Advanced Intelligence Project conducted a preliminary mapping of the affected areas using ALOS-2 data provided by JAXA through Sentinel Asia.

To detect the flooded areas, we carried out a change detection analysis using a pre-event SAR data acquired on April 16, 2016, and a post-event SAR data from July 4, 2020. The image below shows the color composite of ALOS-2 images and the detected flooded areas (blue segments) in Kumamoto, Japan. Visual interpretation results from aerial photos provided by the Geospatial Information Authority of Japan are shown in green polygons (LINK).

Further Information
Sentinel Asia LINK

Disclaimer
The information contained in the map is for general information purposes only. The accuracy of the analysis is not assessed yet. The information is provided by Geoinformatics Unit and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the map or the information, products, services, or related graphics contained on it for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

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The color composite of ALOS-2 images and the detected flooded areas (blue segments) in Kumamoto, Japan. Visual interpretation results from aerial photos provided by the Geospatial Information Authority of Japan (GSI) are shown in green polygons.