土石流之定量判別指標

Quantitative Classification on Debris Flow

連惠邦(Hui-Pang Lien)

《中華水土保持學報》 28卷2期 (1997/06) Pp. 129-136

https://doi.org/10.29417/JCSWC.199706_28(2).0005

摘要

長期以來，鑑別土石流流動形態多數採用外觀特徵的定性描述，而較少從其運動本質衍導出特定的定量關係式，以鑑別土石流，並與一般挾砂水流之流動形態加以區分。因此，本文乃利用水砂混合流體中固體顆粒和液相水體間之驅動能量關係，分別建立泥砂體積濃度和溪床坡度兩參數之臨界公式，以作為鑑別礫石型土石流之定量關係式。經與現場實測資料及室內試驗成果比對驗證，結果相當吻合。研究顯示，屬於土石流流動形態者，不僅其固體泥砂含量必須大於臨界泥砂體積濃度（C_(dmin)），即方程式略同時，其溪床坡度還必須滿足方程式略之要求，使土石流能夠克服沿程的阻力而維持運動。式中tanθ_c為臨界溪床坡度。

關鍵字

土石流 ； 泥砂體積濃度 ； 臨界坡度

並列摘要

To classify the debris flow and the sediment-laden flow is one of the most significant works for modeling studies. However, a qualitative description is often employed to identify the difference between debris-flow and sediment-laden flow, rather than a quantitative description This study indicates a quantitative model based on the relation of the potential energy with Sediment-water mixtured fluid which is composed of solid particles and liquid particles is designed. The model reveals that the minimum volumetric concentration of sediment (C_(dmin)) and critical channel slope (θ_c) are the major parameters to distinguish the difference between debris flow and sediment-laden flow. Those can be expressed as The equation is abbreviated and The equation is abbreviated This models applicability is verified by the data from field surveys and experiments in a tilting flume.

並列關鍵字

Debris Flow ； Volume Concentration of Sediment ； Critical Slope