台東縣海端鄉龍泉溪上游堰塞湖之緊急調查與初步評估

The Urgent Investigation and Preliminary Estimation of Landslide Dam in Lung-Cycan River Upperstream Area

許中立(Chung-Li Hsu) ； 簡益章(Yi-Jhang Jian) ； 邱欣慰(Xin-Wei Giu) ； 張蘇能(Shu-Neng Jhang) ； 吳美玲(Mei-Ling Wu)

《坡地防災學報》 5卷1期 (2006/06) Pp. 105-115

https://doi.org/10.29995/JSHR.200606.0006

摘要

堰塞湖形成原因是邊坡經地震、降水等自然力作用，導致土石體崩塌阻塞河道，造成溪水斷流，在上游蓄積溪水而成湖泊之天然壩體。爲瞭解其貯水量變化、溢流水量、土石壩滲流與穩定性及其對下游可能之影響，利用直昇飛機及無人載具空拍或衛星影像及遙測技術分析研判災害潛勢確有其必要性。
本文以台東縣龍泉溪上游崩塌所形成之堰塞湖爲例，透過協調與團隊分工方式，在短時間內完成緊急調查與初步安全評估工作。經評估分析結果顯示邊坡崩塌的主因爲地震致使邊坡土石滑落，而目前堰塞湖尚屬穩定，如果發生瞬間潰決狀況，對下游萬朝社區水深約有3公尺左右的影響，雖不至於有立即之危害，但仍建請河川管理單位加強下游地區的防範工作，並限制當地民眾至溪床活動爲宜。

關鍵字

堰塞湖 ； 崩塌 ； 空拍 ； 安全評估

並列摘要

Landslide dams have proved to both by earthquake and precipitation natural phenomena that cant to the soil and stone slope collapse hinder the river. In headwaters have size and depth of impoundment natural dams. In order to understand its amount of water stored changes, overflow water amount, earthdam seepage and possible stability influence to the downstream areas, coordinating the support of rescue helicopter and unmanned aerial vehicle to investigate and photograph or the applications of satellite image and remote sensing analysis technique for potential disaster's study and judgement will become more necessary.
This cas study was taking Lung-Cycan river upstream landslide dam formed as a example in Taitung county, through coordinating the way of dividing the work with the group, finish urgent investigation and preliminary estimation the work of safely within short time. The analysis result shows the reason the slope landslide is the major cause earthquake, and the earthdame is still steady on the landslide lake at present. If the Landslide lake breaking takes place in twinkling of an eye, there will be influence about 3 metres on the downstream water level at Wan-Chao commune, although unlikely there is danger immediately, proposed the management goverment of river to strengthen the protection works of downstream embankment, and moved from the riverbed to limit the visitors people.

並列關鍵字

Landslide Dam ； Landslide Lake ； Aerial Photograph ； Stability Estimation