A COMPARISON OF TORRENTIAL RAINFALL-TRIGGERD NATURAL SLOPE FAILURE IN THAILAND AND JAPAN

Recently, in Japan, due to increase of torrential ra infall event with locally-hig h intensity, which may be regarded as one phenomenon of climate change, frequency of subsequent natural slope failure event has drastically been increasing. Therefore, it is an urgent task to clarify mechanism of both surface flow and moisture infiltration into subsoil caused by torrential rainfall, focusing water mass balance in slopes. However, the investigation includes difficulties on data storage on historical rainfall records, and site selection of field monitoring. From such viewpoints, authors had started filed monitoring jointly with Kasetsart Univ., focusing on the similarity of rainfall characteristics between torrential rainfall event with locally-high intensity observed in Japan and squall in tropical countries. In this study, it is discussed to investigate whether or not the findings obtained through field monitoring in Thailand are applicable to torrential rainfall in Japan based on the comparative study of rainfall and geological characteristics in the two co untries. In addition, as well as the introduction of the current research works on early warning system considering the effect of antecedent rainfall on slope failure installed in Thailand, the feasibility of the system to be installed in Japan is discussed.