抄録
Warning and evacuation timing for debris flow has great importance to protect life from debris flow disaster. In this sense, a warning system has been operated since a decade ago in some district. However, it's based on an assumption that debris flow always occures at the time of maximum rain intensity, although considerable amount occures at less rain intensity. Adding to that, the critical rain standard of the warning system tend to be fixed using the method which includes rather empirical “fuzzy” decision of critical line (CL) i. e. the critical rain standard. These factors sometimes cause inaccuracy in warning and evacuation timing.
Hence, some improvement to this inaccuracy is proposed in this report by means of “whole snake line judgement” with which the whole precipitation dynamic pattern can be overlooked. And this method is seemed to be successful for more accurate warning and evacuation timing.
