2 0 0 0 OA 粒径変化を考慮した土石流氾濫予測手法に関する研究
- 著者
- 松本 直樹 和田 孝志 中谷 加奈 里深 好文 水山 高久
- 出版者
- 公益社団法人 砂防学会
- 雑誌
- 砂防学会誌 (ISSN:02868385)
- 巻号頁・発行日
- vol.65, no.3, pp.3-11, 2012-09-15 (Released:2015-08-03)
- 参考文献数
- 19
- 被引用文献数
- 5
Debris flow is composed of mixed-size gravel, and the grain size distribution and concentration of sediment strongly affects the flow behavior. To predict more accurate debris flows, we need a numerical model that considers mixed-size gravel and can describe sediment sorting. We propose a more accurate method for predicting mixed-size debris flow behavior, from torrents to alluvial fans. We combined a debris flow model that can describe sediment sorting with an integration model, and proposed an integrated model for mixed-size gravel. Applying this model, we simulated debris flow on a virtual watershed under different conditions of inflow sediment distribution. Our results showed that an integrated model for mixed-size gravel provide a more rational description of debris flow in torrents and alluvial fans than models of uniform-sized gravel.
1 0 0 0 OA 土石流の規模と地形データの解像度が到達範囲に及ぼす影響
- 著者
- 中谷 加奈 里深 好文
- 出版者
- 公益社団法人 土木学会
- 雑誌
- 土木学会論文集B1(水工学) (ISSN:2185467X)
- 巻号頁・発行日
- vol.74, no.4, pp.I_1201-I_1206, 2018 (Released:2019-03-30)
- 参考文献数
- 23
- 被引用文献数
- 1
土石流の到達範囲には発生規模と地形条件が影響する.地方自治体の設定する警戒区域は,災害履歴と勾配を基に一つの規模を想定して設定されるが,近年は局地的な豪雨等の影響で,より大規模な土石流が多く発生傾向にある.近年,詳細な解像度の地形データが入手可能であるが,到達範囲を検討する際の適切な解像度は十分に把握されていない.本研究では災害事例を基に土石流の発生規模を分類して,異なる発生規模について解像度の異なる地形データで数値シミュレーションを実施した.結果から,小規模の土石流では解像度の違いが影響し,特に流路の地形データへの反映が到達範囲に影響することを示した.
1 0 0 0 OA 平成30年7月豪雨により広島県で発生した土砂災害
- 著者
- 海堀 正博 長谷川 祐治 山下 祐一 崎田 博史 中井 真司 桑田 志保 平松 晋也 地頭薗 隆 井良沢 道也 清水 収 今泉 文寿 中谷 加奈 柏原 佳明 加藤 誠章 鳥田 英司 平川 泰之 吉永 子規 田中 健路 林 拙郎
- 出版者
- 公益社団法人 砂防学会
- 雑誌
- 砂防学会誌 (ISSN:02868385)
- 巻号頁・発行日
- vol.71, no.4, pp.49-60, 2018-11-15 (Released:2019-11-15)
- 参考文献数
- 10
- 被引用文献数
- 8
In July 2018, heavy rain due to Typhoon Prapiroon affected western Japan and caused numerous sediment disasters such as landslides and debris flows in Hiroshima Prefecture. In a southern part of Hiroshima, approx. 8,500 slope failures occurred, and total number of sediment disasters were reported as approx. 1,250. Therefore, members of Japan Society of Erosion Control Engineering and Chuushikoku branch conducted field surveys in Hiroshima City, Aki Gun, Kure City, and Higashi-hirosima City. In Kawasumi area, Aki Gun, large rock which seemed to be core stone and diameter approx. 10 m moved down from the torrent, and at downstream side 6 m diameter rock seemed to hit the house with destructive power. In Aki-Gun, Saka-Cho, Koyaura area, one old stone masonry sabo dam was destroyed. We estimated the flow discharge from the investigation at the upstream of dam and considered the flow process from the flow traces around the dam. The results showed that the dam destroying process was as following. Firstly, the large rocks accumulated at the frontal part of debris flow collided and destroyed the right bank side wing, and then stone masonry product peeled off continuously. Furthermore, debris flows occurred from several streams in Koyaura and 1-1.5 m sediment deposition occurred at downstream residential area. In Higashihiroshima City Kurose-cho, many collapses and debris flows occurred around Hiroshima International University and there were no casualties fortunately. In Kurose-cho, most of the collapses seemed to occur from the top and ridge of the mountains with gentle slope around 15 degrees.
