Preliminary Study on Investigation and Analysis of Slope with UAV

[[abstract]] 台灣的地質條件脆弱，處在環太平洋地震帶上，夏季經常受到颱風侵襲，高聳的山區地形受到強烈的風化作用影響，使山區邊坡容易發生崩塌或是地滑，而近年來氣候變遷加劇，更加深了此影響；然而多處崩塌地因位處偏遠，若派遣人員進行調查，一來費時冗長、成本昂貴，且蒐集資料有限，同時具有一定的危險性，而採用衛星影像則有可能忽略時間間隔較久與解析度不足等缺點。故本研究將探討運用的無人飛行載具進行邊坡調查之可行性。 無人飛行載具（Unmanned Aerial Vehicle, UAV）近年來被廣泛運用於各類的災害調查及防災監測，由於具有重量輕、體積小，機動性及安全性高、維修容易且成本低廉，可在高風險區域執行調查任務。搭配技術純熟的航空攝影測量，將進行調查之空拍影像以控制點接合後，可再製成數值地表模型(DSM)以及正射影像圖，且精細度可以達到5公分，若是邊坡發生破壞前的潛變行為，亦可由不同時序測量結果而發現。 本研究將無人載具應用在仁愛鄉廬山、台14線74.5k人止關處及阿里山五彎仔台18線31k處，藉由所產生之高解析、高精度數值地形與正射影像進行邊坡現況分析及粒子影像分析，研究結果顯示，台14線74.5k人止關於2012年6月形成之堰塞湖來自於右岸邊坡塊體滑落至河道所造成，台14線74.5k人止關及廬山於2014及2015年間雖無明顯較大之降雨事件，經由影像分析顯示坡體仍處於滑移狀態，本研究區仍應持續進行密集監測。[[abstract]]Geological condition of Taiwan is fracture with locating on Pacific Rim seismic area. Typhoons usually attack during summer and steep mountains are highly weathered, which induces landslide in mountain area. The situation happens more often recent years due to heavy weather change. However, most landslides are very far away. Field investigation is time consuming, high budget, limited data collected and dangerous. Investigation with satellite images has disadvantages such as long return period and poor resolution. Thus the possibility for slope investigation with UAV is proposed and discussed in this research. Hazard investigation and monitoring have been adopted UAV in recent years. UAV has advantages such as light weight, small volume, high mobility, safe, easy maintenance and low cost. Investigation can be executed in high risk area. Combining with aero photogrammetry, ground control points, Digital Surface Model (DSM) and Ortho photos can be produced. The resolution can be less than 5cm thus can be used as temporal creeping monitoring before landslide happens. There large landslide sites, Lushan , 74.5k at road Tai-14 and 31k at road Tai-18, are investigated in this research. Current slope condition and particle image displacement was analyzed from temporal satellite images, field investigation, high resolution orhtophotos, and high accuracy DEM from UAV. The result shows that the 74.5k at road Tai-14 landslide dam in 2012 was formed from the landslide located at right bank of river. Moreover, the slope of 74.5k at road Tai-14 and Lushan is still not stable and deforming in 2014 and 2015 without heavy rainfall event. Continuous monitoring should be carried on in these study area.[[note]]碩