Articles | Volume 15, issue 7
Research article
02 Jul 2015
Research article |  | 02 Jul 2015

Modeling debris-flow runout patterns on two alpine fans with different dynamic simulation models

K. Schraml, B. Thomschitz, B. W. McArdell, C. Graf, and R. Kaitna

Abstract. Predicting potential deposition areas of future debris-flow events is important for engineering hazard assessment in alpine regions. To this end, numerical simulation models are commonly used tools. However, knowledge of appropriate model parameters is essential but often not available. In this study we use two numerical simulation models, RAMMS–DF (rapid mass movement system–debris-flow) and DAN3D (dynamic analysis of landslides in three dimensions), to back-calculate two well-documented debris-flow events in Austria and to compare the range and sensitivity of input parameters for the Voellmy flow model. All simulations are based on the same digital elevation models and similar boundary conditions. Our results show that observed deposition patterns are best matched with a parameter set of μ [–] and ξ [m s-2], ranging between 0.07 to 0.11 and 200 to 300 m s-2, respectively, for RAMMS–DF, and between 0.07 to 0.08 and 300 to 400 m s-2, respectively, for DAN3D. Sensitivity analysis shows a higher sensitivity of model parameters for the DAN3D model than for the RAMMS–DF model. This contributes to the evaluation of realistic model parameters for simulation of debris-flows in steep mountain catchments and highlights the sensitivity of the models.

Short summary
In this paper we used two different numerical simulation models to replicate two debris-flow events in Austria and compare the range and sensitivity of the model input parameters. We expect that our results contribute to a better application of simulation models for hazard and risk assessment in alpine regions.
Final-revised paper