由濁流驅動之海底辮狀河道常出現於深海沖積扇上，其形貌特徵與陸上之辮狀河道相似。過去的研究發現水下辮狀河道之活躍辮狀指數與筆直渠道之寬度、無因次水流功率及無因次泥沙水流功率成正比。然而，在自然界中的海底渠道大多並非等寬且筆直，而是會逐漸變寬或變窄。因此，本研究藉由飽和鹽水與砂混合模擬海底濁流進行小尺度之物理實驗，探討不同河道形狀及水砂比對水下辮狀渠道形貌演變的影響，實驗中採用的河道形狀包含菱形、沙漏型及倒梯形。根據實驗結果顯示，活躍辮狀指數和漸進變化的河道寬度呈正比關係。當河道寬度漸寬，會發展出越複雜的水下辮狀河道形貌；反之，當河道寬度漸窄，則會抑制水下河道的辮狀發展。同時，活躍辮狀指數也與無因次水流功率及無因次泥砂水流功率成正相關。在相同寬度下，水砂比增加則會使活躍辮狀指數略微減少。此外，活躍寬度與體積變化量會成正比。這些趨勢都與陸上辮狀河道的研究結果相符。而沙洲的幾何形狀則不受水砂比及河道形狀之影響。除了物理實驗，本研究也使用兩種數值模型代入實驗地形與率定之流量進行模擬。Reduced-complexity model (RCM)定床模擬水流效果良好，而iRIC之Nays2DH模組雖然可以模擬動床，但是將其應用到水下河道之動床模擬則效果不佳。

Submarine braided channels, driven by turbidity currents, have been revealed on several deep-sea fans, displaying similar morphological features to fluvial braided rivers. Past experimental studies on submarine braided channels have shown that active braiding intensity (BI_A) is proportional to fixed confinement width, dimensionless stream power (ω^*) and dimensionless sediment-stream power (ω^(**)).

However, the field-scale submarine braided channels may not restrict to a fixed confinement width. In this study, we use physical experiments to investigate the influence of confinement shapes and inflow-to-sediment discharge ratios (Q_in⁄Q_s ) on the evolution of submarine braided channels. The experimental results show that the BI_A is strongly proportional to the varying confinement width. The measured BI_A is proportional to both the ω^* and ω^(**).Additionally, increasing Q_in⁄Q_s causes a slightly decrease of BI_A. The measured active width (W_a) is proportional to the bulk change (V_bulk). These relations all agree with the published trends of both fluvial and submarine braided channels. For the geometric properties of sandbars, the measured sandbar aspect ratio and sandbar compactness ratio remain constant regardless the change of confinement shape or Q_in⁄Q_s .

In addition to physical experiments, this study employed two numerical models to simulate the experimental terrain and calibrated flow rates. The Reduced-Complexity Model (RCM) performed well in simulating the fixed bed flow, while the Nays2DH in iRIC, although capable of simulating mobile beds, did not perform well when applied to the simulation of mobile beds in submarine channels.

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