Multiscenario flood hazard assessment using probabilistic runoff hydrograph estimation and 2D hydrodynamic modelling

Abstract In this paper, we aim to define a procedure of flood hazard assessment applicable large river basins in which events can be induced/sustained by the full basin area or fractions total as functions extent triggering precipitation event. The proposed is based on combined approach accounting for (1) reconstruction intensity–duration–frequency curves expressing magnitude terms intensity multiple return periods; (2) application soil conservation service method runoff estimation from selected rainfall scenario considering some characteristics (i.e. type, land use/treatment, surface condition, and antecedent moisture conditions); (3) 2D hydrodynamic modelling conducted HEC-RAS model using hydrographs hydrological input data; (4) maps overlaying inundation depicting different periods. To account variability event resulting hydrograph, contributing areas are considered. tested at archaeological site Sybaris southern Italy, periodically involved variable magnitude. obtained results highlight that floodable strongly conditioned period, expected. always simulated flooding process, except smallest only 300-year involves part site. Our findings may useful developing supporting risk management plans area. developed might easily exported other fluvial contexts evaluations scenarios, due geometry extent, needed.