A software package for predicting design-flood hydrographs in small and ungauged basins

In this study, software for estimating design hydrographs in small and ungauged basins is presented. The main aim is to propose a fast and user-friendly empirical tool that the practitioner can apply for hydrological studies characterised by a lack of observed data. The software implements a homonymous framework called event-based approach for small and ungauged basins (EBA4SUB) that was recently developed and tested by the authors to estimate the design peak discharge using the same input information necessary to apply the rational formula. EBA4SUB is a classical hydrological event-based model in which each step (design hyetograph, net rainfall estimation, and rainfall-runoff transformation) is appropriately adapted for empirical applications without calibration. As a case study, the software is applied in a small watershed while varying the hyetograph shape, rainfall peak position, and return time. The results provide an overview of the software and confirm the secondary role of the design rainfall peak position.