非直進式土石流流動案例探討災害影響區之劃定

Debris Flow Non-rectilinear Motion Case Study to Reflect Hazard Zone Delimitation

吳亭燁(Ting-Yeh Wu) ； 陳樹群(Su-Chin Chen)

《中華水土保持學報》 47卷1期 (2016/03) Pp. 24-35

https://doi.org/10.29417/JCSWC.201603_47(1).0003

摘要

本研究以蘇拉颱風在花蓮縣秀林鄉所引發之土石流事件，進行重建並歸納造成土石流改道之原因。為了解其他潛勢溪流是否具有改道之潛勢，透過地形因子選取高屏溪之五條潛勢溪流，進行連續事件的境況模擬。模擬結果顯示部分潛勢溪流具有土石流改道的潛勢，但部分之堆積型態不發生改變。透過定性分析，此種差異與潛勢溪流集水區內岩屑崩滑潛勢、坡度差異、和溝谷地形等有關，透過模擬分析結果，最後提出現行潛勢溪流潛勢度判定之建議。

關鍵字

土石流影響範圍 ； 土石流潛勢 ； 坡度差 ； 情境模擬 ； 地形因子

並列摘要

This study analyzed debris flow disasters in Siou-lin Township in Hualien County during typhoon Soula and summarized factors which triggered debris flow non-rectilinear motion. To clarify the existence of similar susceptibility at other torrents, continuous debris flow scenario simulations were given to five debris flow torrents in Kao-Ping river basin. The simulation results showed part of the debris flow torrents had the susceptibility of being non-rectilinear accumulation, and some of torrents had the same accumulation areas. Qualitative analysis showed this phenomenon occurs with differences in debris slide potential, gradient difference, and gully terrain inside the upstream sub-catchments. Finally, some recommendations were provided for the current hazard susceptibility analysis methods.

並列關鍵字

Debris flow hazard zone ； debris flow potential ； gradient difference ； scenario simulation ； topographic factors