土石流氾濫・堆積の数値シミュレーション

Abstract

To establish so-called soft countermeasures for debris flow hazards, it is essential to delineatethe hazardous zone at the debouchment of a ravine due to a potential debris flow. Because thenatural and man-made features of the areas and the scale and properties of the debris flows aredifferent place to place, data of the actual experiences sometimes contribute little to the issue. Thisis a reason one needs more general method which is capable of predicting the hazardous zone orhopefully the distribution of potential hazards within the zone.This paper presents a numerical simulation method which can calculate the two-dimensionaloverland flow, stopping of the front and deposition of the sediments forming a debris cone on anarbitrarily complex surface feature. The application of the method to the results of laboratory exper-iments verified the method. The processes of the Hora-dani debris flow hazard have been reap-peared by the computer simulation. Although there remain some points to be refined, this wouldbe the first and promising method for the approach to the mitigation of the debris flow hazards.