Flood Peaks and Geomorphic Processes in an Ephemeral Mediterranean Stream: Torrent de Sant Jordi (Pollenca, Mallorca)

The research presented herein studies three episodes of flooding that affected the ephemeral basin of the Sant Jordi stream in northwestern Mallorca. These events are considered common since they do not reach the proportions in terms of the flow rates of other cases that have occurred in Mallorca, but they are nevertheless important due to the impact they have on human activity and also due to the morphological changes caused in the basin itself. On the one hand, the development of the field work to characterize and calculate the peak flows is presented, and on the other hand, the geomorphic changes caused by the water and the materials carried away are explained. The results allow us to identify a type of Mediterranean flood, which happens on a regular basis, but which does not stand out for its flows or for its major socio-economic impacts but still has an effect on the natural and anthropic environment. This information can be valuable for local and regional authorities as well as for the public to avoid risk situations and prevent impacts on public and private property caused by future events.