Unusual becoming Usual: recent persistent-rainstorm events and their implications for debris flow risk management in the northern Apennines of Italy

The alluvial events of Parma (13 October 2014) and Piacenza (13-14 September 2015) in the northern Apennines of Italy have had significant effects in terms of flooding and morphological changes along the main and secondary rivers of the affected areas. The paper presents a summary of the characteristics of the rainstorm events, as well as of the triggered debris flows and their consequences on infrastructures. In the perspective of an extremization of rainfall regimes as a consequence of ongoing climate changes, these phenomena might become quite usual in the future and should be further studied in order to define regional-specific triggering thresholds, analyse precursors from weather radar datasets and assess susceptibility on a regional scale basis.