AN AHP/GM-BASED QUANTITATIVE METHOD FOR DYNAMIC RISK ASSESSMENT OF DEBRIS-FLOW HAZARDS

摘要

An innovative quantitative approach for dynamic risk assessment of debris-flow hazards using the integrated skills of analytical hierarchy process (AHP) and grey modeling theory (GM) is developed and verified with a real case occurred in Taiwan. Theoretical model of AHP is first built for risk assessment of debris-flow hazards where 9 important influence factors considering topological, metrological and rain-fall conditions are selected and their relative risk impacts are analyzed Among these 9 influence factors the GM(1,1) models are employed for intensity of rainfall and accumulated rainfall while linear model is employed for duration of rainfall for prediction. Two predicted schemes are proposed: (1) Single-step prediction (SSP) scheme, and (2) Recycling point-wise prediction (RPP) scheme. The real case of debris-flow disasters occurred Taiwan is tested by the use of AHP/GM: the debris-flow occurred in Tung-Men village, Hua-lien, June 23, 1990. The results show that the proposed AHP/GM integrated quantitative dynamic risk assessment schemes can provide early precaution, warning and alarming in time for the occurrence of debris flow disaster. Using appropriate grey modeling for dynamic influence factors as well as AHP framework and criteria can successfully predict the risk change of debris-flow hazards.