土石流氾濫危険範囲の指定法に関する研究

Abstract

Numerical methods to simulate the processes of stoppage of both a muddy and a stonydebris flows at mouth of a torrent are presented. These methods consist of two-dimensionalmomentum conservation equations and the continuity equations of the bulk as well as thecomponents of fine and coarse solid in the flow. The main difference between the muddyand stony debris flow is the term of resistance to flow in the momentum equations. Thefinite difference scheme of these equations renders possible the calculation of the two-dimensional overland flow, the stoppage of the forefront, the deposition of sediment on anarbitrarily complex surface feature and the distribution of the destructive power on theflooded area, and, thereafter, the hazardous zone due to debris flow can be delineated.