This chapter outlines methods to assess flood hazard and flood risk on alluvial fans. Concepts of flood hazard and risk are discussed as well as uncertainties in predicting floods. Both stochastic and deterministic predictive methods are presented. As an example of a practical stochastic method, a random walk algorithm to compute potential flow paths in the context of a Monte Carlo procedure is outlined. In addition, a conceptual model to link stochastic and deterministic approaches is proposed. Finally, as an example of risk map delineation, the FLO-2D damage assessment procedure is presented that computes flood costs based on damage-depth tables and deterministic model results.
