Debris flow on the gully channel in a large-scale landslide

本研究的目的是定量了解大型滑坡中泥石流的规模、径流方式和临界降雨量等特征。本研究选取Ohya滑坡作为观测场，获得了1993~1994年暴雨期间泥石流的四条水文过程图。结果表明：(1)泥石流峰值流量与降雨强度呈线性关系；(2)峰值流量与总流量呈对数线性关系；(3)泥石流形成的临界雨强分别为7 mm/10min和12 mm/h。(4)泥石流峰值流量为2~13m^3/S，总量约为8000~80000 m^3。

The aim of this study is to understand quantitatively the characteristics of debris flow which occurs in the large-scale landslide, e.g.the scale, the mode of flow down and the critical rainfall. In this study, we selected Ohya landslide as a observed field and obtained four hydrographs of debris flow which occurred in heavy rainfall from 1993 to 1994. The discharge of debris flow rose rapidly as the intensity of rainfall per 10 minutes, and after rainfall abruptly dropped down.From observed hydrogaphs the following results are quoted :(1) The relationship between the peek discharge of debris flow and the rainfall intensity may have a linear relation.(2) Also the relation between peek discharge and the total discharge has a linear on a log scale.(3) The critical rainfall intensity for causing a debris flow is 7mm per 10minutes, 12mm per hour respectively.(4) The Peek discharge of flow rate ranges from 2 to 13 m^3/s and the total volume is from about 8000 to 80000 m^3.