自然ダムの越流決壊によって形成される洪水の予測

Abstract

Failure of landslide dams is one of the main causes of severe flood disaster.Discharges resulting from dam failures can be much larger than those originating from mere strong rainfall. This fact, however, has been only qualitatively known and the quantitative analysis which enables to calculate the process of development of overflow channel on the dam body and the hydrograph of discharge has not existed. This paper, at first, proposes an empirical method to estimate the life span of a landslide dam. Secondly, a system of equations to be used in the numerical simulation of the process of failure and estimation of the discharge hydrograph is given. Comparison of the calculated results to those of the flume experiments proves the method is promissing.