Channel Evolution and Stability Assessment for a Sediment-laden Torrent from the Viewpoint of Fluvial Morphology

in International Symposium (oral presentation paper), 國際研討會(全文口頭發表)
標題Channel Evolution and Stability Assessment for a Sediment-laden Torrent from the Viewpoint of Fluvial Morphology
出版類型國際研討會(全文口頭發表)
出版年度2016
AuthorsWu, 吳嘉俊, 李鎮洋, 蔡驩曦, 陳國威, & Wang 王姵兮
出版日期Dec 1 2016 12:0
會議地點Kyoto
其他編號0000
中文摘要

Typhoon Morakot invaded southern Taiwan in early August 2009 and caused severe torrential flood and vast sediment in Lai-Sher Stream and its tributary. Estimated volume of 13.85 million m3 of sediment from upper watershed as well as that produced by major typhoons in the following three consecutive years has choked the stream channels since. Uncertainty of countermeasures remains in spite of the effort of emergency mitigation and channel dredging at bottleneck section since 2009. Therefore, the objective of this study is to evaluate stream evolution of a 7-km channel reach in Lai-Sher Stream by cross-referencing aerial orthophotos and high-precision digital elevation models that taken eleven times respectively between 1981 and 2015. From the viewpoint of fluvial morphology, channel reach between 3K + 250 and 6K + 200 has changed from a low width-depth-ratio, stable B-2 channel to a moderate width-depth-ratio, high sediment transport capacity A-5 channel. Therefore, this channel reach will continue its scouring process and release the sediment that temporarily stored in the channel. It will eventually reach a G-3 channel. On the other hand, channel reach between 0K + 000 and 3K + 250 is still required dredging operation to elevate its current status in fluvial stability.

校址:912 屏東縣內埔鄉學府路1號 總機:886-8-7703202 傳真:886-8-7740165 系統開發統維護單位:國立屏東科技大學 電算中心 版權所有