A huge earthquake of magnitude M 9.0 occurred at 00:58 (UT), December 26, 2004, in the sea off the west coast of northern Sumatra, Indonesia, followed by a huge tsunami that hit almost all coasts facing the Indian Ocean. We conducted a field survey in the residential area of Banda Aceh, the town of the severest damage by the tsunami, on the west coast of the northernmost point Sumatra, Sigli City, about 80 kilometers east of Banda Aceh three-four weeks after the event. In Banda Aceh, almost all houses in the residential area about 2 km from the coast were swept away, while houses more than 3 km rarely were. Inundation continued about 5 to 6 km from the shoreline. In Lhoknga and several villages on the west coast of Sumatra Island near Banda Aceh, where tsunamis 15 to 30 meters high hit coastal villages, nobody survived. Along the valley about 1 km north of the cement plant, seawater rose to a height of 34.8 m above MSL, which is the highest recorded inundation measured in our survey.

2 関西電力株式会社 土木建築室 技術グループ(〒530-8270 大阪市北区中之島3-6-16) 3 関西電力株式会社 土木建築室 土木建築エンジニアリングセンター (〒553-0003 大阪市福島区福島5-1-7 住友不動産西梅田ビル4F) 4 株式会社ニュージェック 港湾・海岸グループ(〒530-8270 大阪市北区本庄東2-3-20) 5 正会員 株式会社ハイドロソフト技術研究所(〒530-6126 大阪市北区中之島3-3-23 中之島ダイビル26F) 6 株式会社ハイドロソフト技術研究所(〒530-6126 大阪市北区中之島3-3-23 中之島ダイビル26F) 7 ふじのくに地球環境史ミュージアム(〒422-8017 静岡市駿河区大谷5762) 本研究では，津波移動床モデルにおける飽和浮遊砂濃度および流砂量係数の設定が地形変化の再現性に及 ぼす影響を把握するために，東北地方太平洋沖地震津波による岩手県高田海岸における地形変化の再現計 算を行った．その結果，得られる砂移動量の計算値が飽和浮遊砂濃度の設定方法によって大きく異なるこ とが明らかとなった．飽和浮遊砂濃度を固定値として与えると，十分な巻き上げが許容されないために地 形変化の再現性が不十分となった．一方で，飽和浮遊砂濃度を流況に応じて可変とした場合は，水理条件 による時空間的な砂移動量の変動を考慮することができ，大規模な地形変化に対しても良好な再現性を得 ることができた．この際，飽和浮遊砂濃度による制約の効果が大きいために，流砂量係数による計算結果 の差異が小さいことが明らかとなった．

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Under the new regulatory requirements for nuclear power plants in Japan, which were enacted in response to the nuclear accident associated with the Great East Japan Earthquake Tsunami that occurred on 11 March 2011, it is a requirement to establish a site-specific "standard tsunami" based on numerical analysis considering non-seismic factors in addition to general seismic faults. It is necessary to establish a consistent evaluation scheme for estimation of tsunami height induced by submarine landslide, since a standard framework for evaluation has not yet been established even though several models for calculation have been proposed and applied in practice. In this study, we estimated the scale of submarine landslide from a literature survey and showed examples of tsunami height evaluation using multiple schemes. As a result of evaluation of tsunami height using three schemes, the Watts model, the KLS model, and the modified-KLS model, the result obtained by the KLS model was comparatively large for every case.

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