DEBRIS FLOW RULE BASED ON ROUGH SET THEORY EXTRACTION FROM DISASTER CAUSED BY THE NAGASAKI HEAVY RAIN IN JULY, 1982

Abstract

Record concentrated heavy rain hit the Nagasaki Prefecture in July, 1982. It caused a large number of debris flows. It is considered that rainfall makes a prediction of debris flow. Rainfall measures in various regions. However, there are cases where it does not cause debris flows. Therefore, we have to study the natural feature of the region to predict debris flow, since it is not clear to distinguish which torrent is dangerous. This study is clear that essential factor which extracts from natural feature data causes debris flow. We have tried to expand area of rule based on rough set theory. Finally, we have defined new rule and examined validit.