主動崩落型土石流流出特性之試驗研究

Experimental Study on the Properties of Debris Flow

連惠邦(Hui-Pang Lien) ； 林柏壽(Bo-Shou Lin) ； 薛祖淇(Tzu-Chi Shiue)

《中華水土保持學報》 31卷3期 (2000/09) Pp. 217-226

https://doi.org/10.29417/JCSWC.200009_31(3).0005

摘要

本研究乃利用渠槽試驗探討溪流兩岸邊坡土體崩落撞擊溪床堆積土砂而形成土石流之後，其泥砂體積濃度、土砂流出規模及土砂流量等土砂流出特性之變化規律。根據試驗資料分析結果表明，渠槽坡度與流動距離爲影響崩落型土石流土砂流出規模之主要因素，隨著渠槽坡度及流動距離之增加，其土砂流出規模亦隨之提高；惟當流動距離大於或等於10倍渠槽寬度時，土石流已達擬似平衡階段，其泥砂體積濃度和土砂流量即不再隨流動距離而變化；同時，其泥砂體積濃度與渠槽坡度之關係，幾乎與溪床沖刷型土石流一致，顯示在平衡階段之流動條件下，土石流泥砂體積濃度與其形成方式無關。最後，本文也舉出陳有蘭溪沿岸兩處土石流災區之調査資料進行案例分析，結果顯示在總土砂流出量之估算誤差均在6.0％以下，模擬分析結果相當良好，可以提供工程防災設計之參採。

關鍵字

土石流 ； 泥砂體積濃度 ； 土砂流出規模 ； 土砂流量

並列摘要

Previous studies have shown that both flume slope and movement distance are the major factors affecting the movement magnitude of debris flow induced by active landslide from streambank. Increase in the s lope and distance often leads to increase in movement magnitude. However, debris flow will reach the equilibrium stage of constant sediment concentration and discharge when the movement distance is equal to or larger than 10 times the flume width. Meanwhile, the relationship between sediment concentration and flume slope for debris flow induced by landslide is almost the same as that of debris flow triggered by storm runoff. Therefore, the results of this study revealed that sediment concentration of debris flow under equilibrium stage is irrelevant to the formation of debris flow. Finally, two debris flow disaster areas were utilized for model simulation and the estimated sediment volumes had errors within 6%.

並列關鍵字

debris flow ； volumetric sediment concentration ； magnitude of sediment outflow ； sediment discharge