高解像度SAR画像を用いた東北地方太平洋沖地震における 津波湛水域と建物被害の抽出  [in Japanese] Extraction of Tsunami Inundation Areas and Damaged Buildings for the 2011 Tohoku, Japan Earthquake from High-resolution SAR images  [in Japanese]

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Abstract

2011年3月11日に発生した東北地方太平洋沖地震により引き起こされた巨大津波は,日本の太平洋沿岸地域を繰り返し襲い,甚大な被害を引き起こした.本研究では,地震前後に撮影された高解像度衛星TerraSAR-Xの強度画像を用いて,津波による湛水域と建物被害の抽出を行った.後方散乱係数が極めて低いという水域の特性を利用して,地震前後画像から平均差分が減少した地域を湛水域として抽出した.また,1棟単位の建物輪郭データを用いて,輪郭内における後方散乱係数の平均差分と平均相関を算出し,浸水域内における建物被害を抽出した.これらの結果を航空写真の目視判読の結果と比較し,精度を検証した.

The Tohoku earthquake on March 11, 2011, which occurred off the Pacific coast of the northeastern (Tohoku) Japan, caused gigantic tsunamis and brought vast devastation and a huge number of human casualties. Various high-resolution satellites quickly captured the details of affected areas, and were used for emergency response. In this study, the extraction of tsunami inundation areas and damaged buildings were carried out using high resolution pre- and post-event synthetic aperture radar (SAR) images. Since the water surface generally shows very low backscattering intensity, the inundation areas could be extracted by the difference of SAR backscattered intensity between the pre- and post-event images obtained by TerraSAR-X. Then, the changed buildings were detected by calculating the difference and correlation coefficient in the shape of a building. When a changed building was enclosed by the inundation areas, this building was labeled as a damaged building by tsunami. Finally, the results were compared with visual interoperation results to examine the accuracy of the proposed method.

Journal

  • Journal of Japan Association for Earthquake Engineering

    Journal of Japan Association for Earthquake Engineering 12(6), 6_73-6_85, 2012

    JAPAN ASSOCIATION FOR EARTHQUAKE ENGINEERING

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