蘭陽溪上游之地形地質對河床土砂之影響

The Influence of Topography and Geology on the Sedimentation in the Upstream Area of the Lan-Yang Catchment

壽克堅(Ke-Jian Shou) ； 費立沅(Li-Yuan Feit) ； 陳勉銘(Mian-Ming Chen) ； 梁均合(Jiun-Her Linang) ； 黃怡婷(Yi-Ting Huang) ； 林佳霏(Jia-Fei Lin)

《中華水土保持學報》 45卷4期 (2014/12) Pp. 225-233

https://doi.org/10.29417/JCSWC.201412_45(4).0002

摘要

本研究以土砂平衡關係推導出土砂生產指標（IP）及土砂堆積搬運指標（IR），以蘭陽溪流域為對象，選用凡那比及梅姬颱風兩事件，針對集水區之土砂平衡進行探討。於兩項指標分別選用不同因子圖層，再利用GIS軟體進行多變量分析。由分析結果發現，土砂材料因短時間內無法即時搬運至下游地區，大多還堆積至集水區上游處，若無法運移至下游處達到平衡，未來再發生大規模之暴雨事件，可能誘發大規模土石流、山崩及土砂運移現象，造成下游二次災害。

關鍵字

地理資訊系統 ； 土砂生產 ； 土砂堆積運移 ； 影響因子分析

並列摘要

Changes of river morphology are closely related to discharge, transport capacity, and sediment supply. This study derives the equilibrium equation of sediment and defines two indexes, the sediments generation index IP and the sediments transportation and deposition index IR. Focusing on the impact of Typhoon Fanapi and Typhoon Megi on the Lan-Yang River watershed, this study investigates the control factors of the above two indexes, including topography, geology, rainfall, river morphology, landslide, etc. The results suggest that the sediments generated by Fanapi were transported to the middle segments of the Lan-Yang River. However, there are still areas with severe sediment accumulation, where treatments including dredging or earth working are necessary. Those areas need to be carefully handled since they are highly prone to becoming a secondary hazard due to typhoons or heavy rain.

並列關鍵字

GIS ； sediments generation ； sedimentation transportation and deposition ； control factors