Design hydrograph estimation in small and fully ungauged basins: a preliminary assessment of the EBA4SUB framework

Design hydrograph estimation in small and ungauged basins is still a critical issue in hydrological studies. Although a great effort has been devoted to improving the knowledge on this topic in the last 10 years, some unresolved problems still limit the practitioners. Indeed, in small and ungauged watersheds located in areas where regionalisation analyses are not available, hydrologists still typically apply the rational formula. In a recent contribution, we proposed an event-based framework illustrating its potential benefits over the widely used rational formula and underlining its tendency to be less sensitive and less subjective. In the present contribution, we present a preliminary assessment of the proposed framework, analysing its application to five watersheds for which enough observed data are available to provide an evaluation of the model's performance. Although the results confirm that the design hydrograph estimation in small and ungauged basins is affected by relevant errors and uncertainty, they also show that the proposed framework is promising for practical hydrology.