| 講演要旨(和文) | | 津波が越流したとされる岩手県陸前高田市広田町のため池堤体において，電気探査，地中レーダー探査および簡単な弾性波探査を行った．ため池の除塩の効果を把握することを目的としている．電気探査では電気伝導度の分布図を得た．地中レーダー探査と弾性波探査では反射の強度を示す相対強度の分布図を得た．その結果，時間の経過とともに堤体内の塩分濃度は減少し，塩分濃度が高い領域は地下水面より上に存在し，震災から1年以上経過しても局所的に塩分濃度の高い領域が存在していると考えられる． |
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| | 講演要旨(英文) | | Electrical resistance survey, ground penetrating radar (GPR) survey and elastic wave exploration were performed in irrigation tank embankment submerged in sea water due to the tsunami. The objective of this study was to grasp the effect on desalinization of paddy field and irrigation tank embankment using geophysical exploration. The distributions of electric conductivity were obtained from the results of electrical resistance survey. The distribution of relative reflection strength of electromagnetic waves was obtained from the result of GPR survey. The distributions of relative strength of seismic reflection were obtained from the results of elastic wave exploration using geophone. As a result, it is found that the salinity concentration in the observed embankment decreases with the time passage. It is inferred that the area of high salinity concentration is above the water table. Even if one year or more passes from the tsunami, the area where the salinity concentration is high exists locally. |
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