Variable hydrograph inputs for a numerical debris-flow runout model

Abstract. Debris flows affect people and infrastructure around the world, as a result, many numerical models modelling approaches have been developed to simulate their impacts. Observations from instrumented debris-flow channels show that variability in inflow depth, velocity, discharge real debris is much higher than what typically used simulations. However, effect of this natural on model outputs not well known. In study, we examine effects using complex time series within single-phase runout utilizing Voellmy flow-resistance model. The interactions between topography flow resistance were studied first simple triangular hydrograph, which showed simulated discharges change because local slopes parameters. Next, more inflows tested based 24 hydrographs initiated three locations. We described method scale by defining target event volume maximum allowable peak discharge. results large variation depths velocities arising variable inflow. variable-inflow conditions demonstrated simulations two case histories flows, where leads significant variations simulation outputs. provide an indication range impacts may result conditions. These demonstrate can lead reasonable estimates potential