摘要
本研究藉由渠槽試驗模擬單根漂流木在定床渠道之初始起動情形，並探討不同漂流木長度、直徑、與水流夾角及底床粒徑對漂流木初始起動水流條件之影響。試驗發現，當漂流木與水流方向平行時，隨著水深逐漸增加，漂流木所受之浮力隨之增加，摩擦阻力則逐漸減小，直至漂流木開始發生運動，此時漂流木會以半浮動半滑動的方式向下游移動；而漂流木與水流方向傾斜及垂直時，則皆為滾動之方式向下游移動。綜合試驗與模式預測之結果得知，漂流木能否穩定停留在渠道中，主要跟漂流木與水流之夾角、漂流木密度、直徑、渠道坡度及底床粗糙度等因子有關。本研究由試驗結果推導出漂流木初始起動無因次迴歸曲線。因此，在進行漂流木穩定性判定時，可參考本研究所提出之漂流木初始啟動關係式，作為簡單之判定依據。
並列摘要
This research used a flume experiment to simulate the entrainment of single wood and explore the influences on the flow condition of large woody debris (LWD) entrainment under different lengths and diameters of LWD, grain sizes, and the flow angle between the LWD and the central flow. The results showed the LWD started to move downstream by semi-floating and semi-sliding when the LWD was parallel with the flow. The motion occurred because of the increased water depth, increased buoyancy, and decreased friction force. However, the LWD was rolling downstream while the LWD was oblique or transverse to the flow. The results showed the main factors causing LWD to remain stable in the channel were the flow angle between the LWD, the density and the diameter of the LWD, the channel slope, and the bed roughness. The regression analysis showed the significant fit dimensionless model of the LWD entrainment in the experiment study. Therefore, the results provided simple principles to predict the stability of the LWD.
延伸閱讀
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- 陳鋕銘（2015）。漂流木犯罪初探。生態台灣，(48)，28-31。https://www.airitilibrary.com/Article/Detail?DocID=19914903-201507-201508040003-201508040003-28-31
- 羅婉心（2021）。仿生設計應用於漂流奇木燈飾之創作研究〔碩士論文，國立臺中科技大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0061-1307202115452500
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