|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Agriculture / Faculty of Agriculture >
Peer-reviewed Journal Articles, etc >
Sediment pulse発生後における土砂の波状移動と分級現象
| Title: | Sediment pulse発生後における土砂の波状移動と分級現象 |
| Other Titles: | Influence of the mobility of the coarse particles on the sediment pulse evolution in torrential rivers |
| Authors: | 宮崎, 知与1 Browse this author | | 山田, 孝2 Browse this author | | 丸谷, 知己3 Browse this author →KAKEN DB |
| Authors(alt): | Miyazaki, Tomoyoshi1 | | Yamada, Takashi2 | | Marutani, Tomomi3 |
| Keywords: | initial sediment pulse and its evolution | | particle size sorting | | the mobility of the coarse particles | | quasi-stream-power | | magnitude of the sediment delivery |
| Issue Date: | Jul-2008 |
| Publisher: | 砂防学会 |
| Journal Title: | 砂防学会誌 |
| Volume: | 61 |
| Issue: | 2 |
| Start Page: | 5 |
| End Page: | 15 |
| Publisher DOI: | 10.11475/sabo.61.2_5 |
| Abstract: | Understanding how sediment supply from lateral source influences on sediment distribution along a channel reach is a key issue for preliminary surveying of sediment disaster. Sediment pulse formed by storm-induced sediment supply from lateral source was investigated for four years after 2003 storm at Kita-iwanai-ninosawa Creek located in a headwater catchment of Tokachi River, Eastern Hokkaido, Japan. Cross-section measuring and sediment sampling were conducted on site, and the relationship between longitudinal changes in sediment volume transformed to a sediment mass curve and grain size distribution was examined. In this paper, the ratio of sediment delivery magnitude (M) against quasi-stream power (Ps) was employed as an efficiency index (M/Ps) of sediment transfer. The result is an follows: 1) Although storm-induced sediment pulse formed by quite lots of sediment input is not identified by deference in grain size, sediment pulses gradually reproduced by low-water flow after storm event have characteristics of grain size distribution. 2) Magnitude of sediment delivery with large materials (>75 mm) decreases downstream because of their short travel distance even by flooding. However, selective transport of smaller materials by low-water flow increases the magnitude of sediment delivery. 3) Comparing sediment mass curves, the wave peak by large-magnitude flooding is higher than that by small-magnitude flooding, and the wave length by large-magnitude flooding is shorter than that by small-magnitude flooding. 5) The efficiency index (M/Ps) of sediment transfer yielded by storm-induced sediment supply is quite high, but it gradually decreases with time after initial sediment supply. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/67997 |
| Appears in Collections: | 農学院・農学研究院 (Graduate School of Agriculture / Faculty of Agriculture) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 丸谷 知己
|
