應用遙測技術結合空載LiDAR探討神木地區莫拉克颱風引致土砂災害及產量評估

Induced Typhoon Morakot in Shenmu Village Using Remote Sensing Technology and Airborne LiDAR

何幸娟(H. C. Ho) ； 林伯勳(B. S. Lin) ； 尹一帆(Y. F. Yin) ； 冀樹勇(S. Y Chi) ； 施美琴(S. M Chin) ； 尹孝元(H. Y Yin)

《水保技術》 5卷4期 (2010/10) Pp. 191-203

https://doi.org/10.30040/JSWCT.201010.0001

摘要

莫拉克颱風挾帶超大豪雨以及高強度降雨肆虐全台，致使神木地區於2009年8月8日晚間，累積雨量高達900mm，並超過當地200年降雨重現期，造成當地溪水暴漲，河道兩岸淘刷嚴重且有多起大規模崩塌，頓時大量土砂以土石流或高流量挾砂水流型態不斷將土砂往下游帶送，致使愛玉子橋遭沖毀且河道最大約拓寬50m。由於，神木地區具有獨特地形特性，且集水區地形尚處幼年期，沖蝕情況劇烈，土砂材料供應不絕，加上地勢陡峻及累積降雨量易超過河川負荷量，坡地災害頻傳。鑑此，本文建議透過遙測技術結空載LiDAR施測，綜觀集水區上游至下游災害全貌，評估潛在土砂產量及空間分布，提供下游做爲判斷災害潛勢之可靠資訊，以有效減輕災情損失及致災風險。

關鍵字

莫拉克颱風 ； 神木地區 ； 災害潛勢 ； 空載LiDAR

並列摘要

Typhoon Morakot brought heavy rainfall with high intensity assaulting Taiwan Island in August 8, 2009. Its accumulated precipitation reached up to 900mm over 200 year return period so that it made river water rising highly which scoured riverbank seriously and caused lots of big size landslide in the upstream. Suddenly, large amounts of sediment flowed into river and transformed debris flows which transported to the upstream area and resulted in many damages. And, the bridge across Aiyuzih creek was directly crushed and the river width had been broadened at a maximum of 50m. Due to the particular characteristic of geology and steep landforms, sediment disasters in Shemu Village occurred frequently than other area. In view of those points, this paper suggests using remote sensing technology and airborne LiDAR is to identify and analyze the features of sediment disaster. Furthermore, spatial distribution of potential sediment discharge will be estimated for providing the useful information to mitigate loss from hazards and reduce the risk of vulnerability to the downstream area.

並列關鍵字

Typhoon Morakot ； Shenmu Village ； Debris Flow ； LiDAR