本研究探討不同水砂比對於渠道回淤與沖積扇堆積形態之影響，實驗使 用的顆粒為粗砂，在不同砂量、不同濃度的水砂比進行實驗，藉此觀察沖 積扇的平面堆積形態變化與歷程以及渠道回淤現象；實驗觀測顆粒由儲存 槽經由渠道堆積於平台上之變化，乾砂顆粒在此坡度渠道之顆粒性質，以 及顆粒摩擦力與邊壁效應對渠道回淤之結果；改變不同的水砂比，對於顆 粒之堆積或回淤造成什麼影響，討論顆粒之向源回淤現象，平面堆積時扇 面之發展情況，在水砂比 n=2.5 之情況下，扇面所觀察到的扇面回填、脫 離改道和河道化現象，以及渠道回淤時不流動層前端發生之渦流現象。;The effect of water-sediment ratio on channel accretion and alluvial fun aggradation is experimentally explored in this study. The experimental observation of the sand particles from the upstream storage tank through the feeding channel, and their final accumulation on the platform were performed by adjusting different discharges of water and sediment, respectively. The experimental results show that the progradation of the fan is proportional to the square root of the time at given discharge. In the cases of the water-sand ratio greater than 2.1, the processes of backfilling, avulsion and channelization were observed during the formation of the alluvial fun, while a moving shock propagated in the upstream direction in the feeding channel.
