| Summary: | 碩士 === 國立暨南國際大學 === 土木工程學系 === 93 === The mountainous geography, young geology and subtropical climate provide a developing environment for the occurrence of debris flow in Taiwan. The 7.3 chi-chi earthquake, which happened on September 21, 1999, induced a lot of landslides in mountainous region. It was observed that the characteristics of debris flow changed after earthquake. In this study the difference of characteristics is presented and the effect of strong earthquake on the occurrence of debris flows is discussed. Three regions are selected as the study areas for comparing the effects of different magnitudes of ground motion on debris flows. The air photos dated in 1997 (before the earthquake, and after the strike of typhoon Herb) and 2002 (after the earthquake, and after the strike of typhoon Toraji) of these regions are used to identify the occurrence, location and size of debris flows. Using GIS to acquire the geological and geographical characteristics of these debris flows. The Neuro-Fuzzy network is applied to evaluate the potential of debris flows of these study regions. The basic data, including the occurrence and non-occurrence flows are input into the network in a fuzzy approach. These discriminating data is used to train a potential-predicting model by Neuro-Fuzzy network. The effect of earthquake on the potential of debris flows is studied through the comparison of the potential of debris flows in each region before and after the earthquake.
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