Investigating compound flooding in Como

Compound events are extreme events whose impact is enhanced by the synergy, in time and/or space, of multiple variables. An example of this typology of events is provided by compound flooding. In this case, the resulting flooded area is increased by several factors, combining together; for example, the contemporaneous occurrence of high sea level and heavy precipitation (multivariate event), the presence of high soil saturation prior to rainfall events (preconditioned event), a precipitation event affecting several basins (spatially compounding event), or a succession of precipitation events (temporally compounding event). In this respect, we have adopted a compound analysis to study a series of floods that affected the town of Como (Northern Italy). Indeed, the town experiences recurrent damages due to the flooding of the nearby lake. In particular, we collected and analyzed 53 flood events, covering the period 1981-2020, in order to gain a better and more in-depth understanding of the phenomenon. This may eventually have important implications for the prediction and risk reduction of compound flooding.