著者

佐藤 剛 木村 誇 廣田 清治 鄒 青穎 八木 浩司

出版者

公益社団法人 日本地すべり学会

雑誌

日本地すべり学会誌 (ISSN:13483986)

巻号頁・発行日

vol.56, no.3, pp.129-134, 2019 (Released:2019-06-07)

参考文献数

6

被引用文献数

3 4

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A heavy rain event in July 2018 caused many natural disasters such as landslides and floods in western Japan. Many shallow landslides were induced by heavy rain between the night of July 6 and the morning of July 7 in Gogoshima Island, which is located offshore of Matsuyama City, Ehime Prefecture. The main industry of the island is the cultivation of oranges. However, the orange farming infrastructure was devastated by shallow landslides across a large portion of the island. We created a spatial distribution map of the shallow landslides, based on interpretation of the SPOT-7 satellite imagery, to understand their characteristics. Moreover, the mass movement processes were clarified using the results of geomorphological and geological field surveys. The analysis revealed the following : 1) The shallow landslides induced by the heavy rain event were distributed across the island, and the total number of landslides was 207. 2) Relatively elongate, shallow landslides are distributed on the slopes of Mt. Kofuji. The shallow landslide materials changed to debris flows. 3) The field survey revealed that the heads of shallow landslides are located on the geological boundary between granodiorite and andesite. The landslide material was formed of loose, highly weathered granodiorite, called “masa” in Japanese, and thermally metamorphosed granodiorite. 4) The previous debris flow deposits that filled the gullies were eroded by the new debris flows and flash floods.

著者

鄒 青穎 田口 一汰 佐藤 龍之世 石川 幸男 檜垣 大助 蔡 美芳 五十嵐 光 山邉 康晴

出版者

公益社団法人 日本地理学会

雑誌

E-journal GEO (ISSN:18808107)

巻号頁・発行日

vol.18, no.1, pp.142-156, 2023 (Released:2023-06-01)

参考文献数

31

被引用文献数

1

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津軽十二湖地すべり地は,白神山地の最西部,青森県津軽国定公園にある約300年前の地震によってできた地すべりである.そこには,流れ山や舌状小尾根地形や巨礫や湖沼群など,十二湖を形成した地すべりの運動やその範囲を示す痕跡が各所に見られる.ここへの来訪者の多くは,推奨散策ルート沿いに1~4時間滞在し,池とブナ自然林の自然風景を鑑賞するために訪れている.来訪者は,地すべりに関連する池の成因や地形と植生との関係への興味が高いが,地学や地生態学的要素に関する情報は来訪者には伝わっていない.そうしたギャップを解消するため,十二湖の地形のできかたとその上に成り立った地すべり地形と植生の対応関係について調査を行い,それらへの理解が深まる散策ポイントを巡る散策マップを作成した.