Hydraulic model tests for propagation of flow and sediment in floods due to breaking of a natural landslide dam during a mountainous torrent |
| |
| Authors: | Takahiro Itoh Akihiko Ikeda Takahiko Nagayama Takahisa Mizuyama |
| |
| Institution: | 1. Research and Development Center, Nippon Koei Co., Ltd, 2304 Inarihara, Tsukuba, Ibaraki 300-1259, Japan;2. Sabo & Landslide Technical Center, 4-8-21 Kudan-Minami, Chiyoda-ku, Tokyo 102-0074, Japan;3. Hokuriku office, Nippon Koei Co., Ltd, 5-1-43 Eki-nishi Honmachi, Kanazawa, Ishikawa 920-0025, Japan;4. National Graduate Institute for Policy Studies (GRIPS), 7-22-1 Roppongi, Minato-ku, Tokyo 106-8677, Japan |
| |
| Abstract: | During mountain torrents, large-magnitude floods may result from heavy rainfall and cause the breakage of landslide dams naturally formed by heavy rainfall, earthquakes, and so on. The characteristics of longitudinal spreading of clear water discharge and changes in flow depth must be clarified because the changes in peak depth have not yet been examined in steep-slope torrents and because there are few data on spreading of flash floods and related sedimentation in mountainous torrents. In the present study, experimental data were collected through hydraulic model tests over a rigid bed, and the spreading of water, fine sediment, bed load, and large boulders due to flooding are discussed assuming that flash flooding/debris flows occur in the upstream reach. The effects of changes in flow width, such as expansions and contractions in the flow width, as well as changes in meandering channels, sediment transportation, and spreading flow depth resulting from bores are examined using flume data for a steep-slope torrent. The data obtained in the present study reveal that fine sediment components are transported to the downstream reach if large-magnitude floods occur and that the spreading rate and peak lags of the fine sediment and water level indicate the occurrence of a flood in the upstream reach. |
| |
| Keywords: | Propagation of water and sediment Debris flow Flash flood Hydraulic model tests Flow width |
| 本文献已被 CNKI ScienceDirect 等数据库收录！ |
|
