Risk and size estimation of debris flow caused by storm rainfall in mountain regions  

作　　者：CHENG Genwei Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China 

出　　处：《Science China(Technological Sciences)》2003年第z1期12-19,共8页中国科学（技术科学英文版）

基　　金：This work was supported by the Knowledge Innovation Project, Chinese Academy of Sciences (KZCX2-SW-319);the National Natural Science Foundation of China (Grant No. 30271042).

摘　　要：Debris flow is a common disaster in mountain regions. The valley slope, storm rainfall and amassed sand-rock materials in a watershed may influence the types of debris flow. The bursting of debris flow is not a pure random event. Field investigations show the periodicity of its burst, but no directive evidence has been found yet. A risk definition of debris flow is proposed here based upon the accumulation and the starting conditions of loose material in channel. According to this definition, the risk of debris flow is of quasi-periodicity. A formula of risk estimation is derived. Analysis of relative factors reveals the relationship between frequency and size of debris flow. For a debris flow creek, the longer the time interval between two occurrences of debris flows is, the bigger the bursting event will be.Debris flow is a common disaster in mountain regions. The valley slope, storm rainfall and amassed sand-rock materials in a watershed may influence the types of debris flow. The bursting of debris flow is not a pure random event. Field investigations show the periodicity of its burst, but no directive evidence has been found yet. A risk definition of debris flow is proposed here based upon the accumulation and the starting conditions of loose material in channel. According to this definition, the risk of debris flow is of quasi-periodicity. A formula of risk estimation is derived. Analysis of relative factors reveals the relationship between frequency and size of debris flow. For a debris flow creek, the longer the time interval between two occurrences of debris flows is, the bigger the bursting event will be.

关 键 词：DEBRIS flow  periodicity  estimating method. 

分 类 号：P642.23[天文地球—工程地质学]