單根漂流木之初始起動理論模式

Incipient Motion Theoretical Model of Single Large Woody Debris

10.29417/JCSWC.201203_43(1).0002

陳樹群(Su-Chin Chen)；王啟榮(Ci-Rong Wang)；趙益群(Yi-Chin Chao)

漂流木 ； 理論模式 ； 漂流木起動水深 ； Large woody debris(LWD) ； theoretical model ； LWD entrainment depth

中華水土保持學報

43卷1期（2012 / 03 / 01）

12 - 20

繁體中文

漂流木部分浸末於水流時，會因與水流不同夾角等因素，產生滑動或滾動之現象。本文結合滑動與滾動之力學平衡機制，建立單根漂流木初始理論起動無因次水深模式。模擬結果顯示，漂流木初始起動水深與水流之夾角及渠道坡度呈現負相關之關係；而且漂流木直徑與密度對漂流木初始起動所需之水深有顯著的影響。本文亦與陳樹群等（2011）之渠道試驗結果相驗證，結果顯示本文所發展出之模式在預測理論起動水深時有良好之表現能力。

The entrainment depth theoretical model for single large woody debris (LWD) has been developed and discussed in terms of the influences of LWD characteristics, channel properties, and different piece angles relative to flow direction. This study integrated a sliding and rolling equilibrium mechanism to establish a theoretical model of wood entrainment depth. The simulated results showed LWD entrainment depth is negatively correlated with different flow angles and channel slope. In addition, the LWD diameter and density significantly influences LWD entrainment depth. The simulated results compared with Chen et al. (2011) showed the theoretical model could effectively [predict???] the incipient depth of LWD entrainment.