Many friction relations or flow laws have been proposed to describe the flow and
stopping behavior of debris flows. Practical application requires knowledge of the typical range of parameters as well as knowledge of the suitability of the flow laws to the torrent under investigation. Here we systematically compare a wide variety of debris flow laws using two one dimensional numerical simulation models of debris flows and field data from an automated debris flow observation station at the Illgraben torrent, Switzerland. Both models solve the shallow water equations and incorporate a frictional resistance term that describes the properties of flowing debris. The DFEM model uses the finite element method; debris flow friction relations, or flow laws, include the Voellmy fluid, simplified Bingham, and dilatant/grain shearing relations. The WAF-DF is based on the Weighted Average Flux method and has been successfully applied to describe debris flow propagation and the propagation of roll waves superimposed on debris flows. Debris flow laws include the Herschel-Bulkley and general viscoplastic formulations. Both models are compared with field observations to provide the closest match with the observations, providing typical values of debris flow parameters for the various flow laws.