近年來滑坡災害發生頻率逐漸增加，倘若土石流或崩塌之土體向下游移動，產生大規模陸源沉積物並迅速進入水中，形成水下土石流、海底山崩等，並引發海嘯衝擊居民生命財產安全，因此水下大型質量體運動行為成為新興且急迫的研究議題，然而水下大型質量體運動因不易觀察，多以數值方法或實驗方式進行探討，但為了有效模擬其運動行為，來推估其流動特性，本文將以實驗方式探討一二維傾斜渠道顆粒流崩落運動現象，利用高速攝影機拍攝，並透過影像處理探討其顆粒流整體流動過程。在本研究中我們藉由不同釋放位置(水上、水下)、不同量體及不同顆粒大小情況下對水下質量體運動形貌變化並加以歸類，觀察記錄顆粒流之運動行為、流動速度，除了探討其顆粒流整體流動行為，我們亦發現當釋放量體越重，形貌變化越緩慢及堆積量百分比越少；有趣的是，於水下釋放時顆粒流之平均速度均快過於水上釋放，且量體越多，其最終堆積距離也較長，此外實驗最後應用粒子影像法來量測顆粒流之流況分析，希望探討其顆粒流之完整性。

In the last few years, landslide-disasters have occurred frequently. If debris flows or downstream happened, it’ll produce huge of terrigenous sediments which moves quickly into the water, become subaqueous debris flows, submarine landslides, and so on…… It might cause tsunamis to happen and cause serious threat to the resident and their property. Therefore, subaqueous mass movement behavior has became a current and urgent research topic. However, subaqueous mass movement is difficult to observe, so we must mostly use numerical methods or experimental approaches to investigate it.
In order to simulate effectively its movement, and forecast its likely motion. This article will investigate two dimensional slope channel, granular flow, and collapse by scientific experiment. Using high speed cameras and image processing to discuss whole of the granular flow. In the experiment, we use different factors, such as dryness, subaqueous volume, and weight to classify subaqueous mass movement and configuration change. Observing and recording granular flow performance, and speed is necessary, not only probe granular flow movement, but we also discover that the heavier weight we add, the slower the outward appearance and the smaller percentage that it deposits. Another interesting fact is, when releasing the granular flow subaqueous, its average velocity is faster than dry. Not only this, but we also discover that the more weight you apply, the longer stacked distance you get. In addition, with the experiment using Particle image velocimetry (PIV) to measure granular flow’s flow conditions, we hope we can investigate the principles of the granular flow.

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