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.
- 著者
- 黒岩 知恵 平松 晋也
- 出版者
- 公益社団法人 砂防学会
- 雑誌
- 砂防学会誌
- 巻号頁・発行日
- vol.63, no.4, pp.16-21, 2010
Many hillside landslides and debris flows occurred by typhoon T 0421 in Miyagawa village (the present Odai town) on September 29, 2004. These caused severe sediment-related disasters. In this study, several findings on the influence of precipitation, slope angle and forest practice on hillside landslides caused by typhoon T 0421 were shown in Miyagawa-dam basin as follows : 1) Correlation between precipitation and collapsed area ratio was not clear. 2) Angle of collapsed slope in deforestation sites was 5-10° lower than those of non-forestation and reforestation sites. 3) Collapsed area in deforestation sites occupied 57% in total collapsed area. 4) Most of landslides were occurred since 10 to 20 years after deforestation. 5) More hillside landslides observed in larger deforestation area. 6) A prediction model of slope stability changes considering forest practice (Kuroiwa and Hiramatsu, 2004) was applicable to Miyagawa-dam basin. As the result of this simulation, collapsed area is generally in proportion to collapsing possibility area ratio index (APhr(t)). 7) Angle of collapsed slope and APhr(t)and collapsed area ratio showed significant correlation.