June 2011 Imaging the Areas Affected by Torrential Rains in Akita Prefecture (Koyoshigawa River, Akita Prefecture)

As a result of the impact from heavy rains on the rain front, Akita Prefecture witnessed the highest levels of precipitation on record in June. All areas in the prefecture were hit successively by damage in the form of rising river waters, landslides, and flooding in homes and on the roads.
Due to these torrential rains, the levee (on the left bank of Ishizawagawa River) near the intersection of Class A river systems, the Koyoshigawa and Ishizagawa rivers flowing through the southern part of the prefecture, collapsed.

Imaging Using TerraSAR-X (Synthetic Aperture Radar)

Imaging Specifications

Acquisition dates and times : June 25, 2011, 5:51 (JST)
Angle of incidence : 31°
Imaging mode : StripMap
Product type : EEC
Polarized wave : HH

PASCO carried out emergency acquisition of the affected areas using the synthetic aperture radar (SAR) satellite "TerraSAR-X" at 6:00 pm on June 25.
The images were characterized by the weak backscattering intensity of microwaves on the smooth water surface. These were captured as dark shades on the images.
The agricultural lands (paddy fields) located on the lowlands along Koyoshigawa River were observed to be flooded over a distance of several kilometers (from the intersection with Ishizawagawa River to the area near the intersection with Sakaigawa River intersection).
The sections highlighted in blue show the flow path in the event that the river waters do not rise.


Estimated Range of Inundation

The area shown in blue in the figure on the right is the estimated range of inundation resulting from this flood disaster. Comparing images from before the disaster (taken on December 31, 2010) and after the disaster (taken on June 25, 2011), we extracted the range of inundation that had spread due to this flood.


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History of Information Released


From the perspective of understanding the damage situation caused by the disaster, and of providing information to the relevant organizations, PASCO carried out estimations for the areas of damage immediately utilizing SAR satellite images, which are not impacted by weather conditions.

We express our deepest sympathy to all who have been affected by the disaster.
We will strive even harder to be of service to all through the application of our spatial information processing and analysis technologies, as well as through our disaster prevention consulting expertise, in order to obtain accurate information on the disaster situation and assist in the recovery of the affected areas.

<TerraSAR-X : InfoterraGmbH, Distribution [PASCO]>
*The reuse or copying of images and other information available here without prior permission is strictly prohibited.

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The copyright for the documents recorded in the disaster and emergency photos of this page belongs to PASCO CORPORATION.
In addition, the copyright for the use of TerraSAR-X in this page is also the property of PASCO CORPORATION.
Please contact us for permission to distribute or copy the information (documents and images) recorded in this page.

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PASCO CORPORATION strived to make the information in this page as accurate as possible at the time of publication; however PASCO CORPORATION does not guarantee integrity or accuracy of the information recorded in this page. PASCO CORPORATION accepts no liability for any loss or damage directly or indirectly, arising from the use of this information or contents. In case the information provided in this page is evidently different from the actual, in order to correct it please contact us.

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