Due to climate change extreme events will become more frequent and more intense in the future. Hence, a better understanding of the physical processes associated with highly unsteady flows is essential. Among these, tsunamis, storm surges and flash floods are the most common. Due to their rarity and complexity, experimental approaches are required and dam-break waves are often use to reproduce tsunami-like flows. However, most laboratory tests are conducted on (unrealistic) smooth inverts, hence rising the question on how the bed roughness affects the hydrodynamic properties of these flows. Based on a large experimental campaign with multiple repetitions, these results show a clear dependence of the wave front celerity and inundation depth on the bed roughness, providing additional knowledge and new empirical expressions that will support researchers and practitioners in predicting the behavior of these unsteady flows during future extreme events.
