**Author details**

The usability of the model to compute an "index" has been proven elsewhere, and it is confirmed on the present application to the 2016 case study, to Bormida, Tanaro, and Chisola

The comparison between the computed "index" and the *collected* residential and productive damages proves that if the former should be used to estimate the real damages, an *over-* or *under*estimation of the latter could be done. Moreover, collected damages can be very different with respect to real damages. This is due to the many factors, including the attitude of privates, or legislation. Application to Bormida river also showed a strong variability in the

For this reason, it should be considered that, at the present state, a real calibration of the model is not possible and the use of the term *index* should be maintained. However, the IDP can be a useful index to estimate the order of magnitude of the total indemnification requests by privates or to estimate the total flood costs. Available data on 2016 flood show that, for Alessandria and Asti provinces, the total costs are between 1.6 and 3.9 times the private

The adoption of the IRP allows the risk quantification and its ranking; in spite of the fact that, at present, risk quantification in EFD is not compulsory, in this frame, IRP can be a useful instrument to (i) improve risk ranking and mapping and to (ii) estimate damages for the

Obviously, over/underestimations by the model should be taken into account by decision

The authors would like to thank the contributions of V. Laurino and I. Longo for the scientific research carried on during the preparation of their Bachelor thesis in the University of Turin and Politecnico of Turin, respectively. This research has been possible by a strict and no-profit

The authors declare that there are no existing or possible conflicts of interest, including financial, personal, or any other relationship which could influence their scientific work, at the time

collaboration among Public Administration, the Politecnico, and the University.

DPCM Decree of the President of the Ministry council

EFD European Flood Directive

total amount of indemnification requested by economic activities.

32 Natural Hazards - Risk Assessment and Vulnerability Reduction

makers and public administration, especially in Re.N.Di.S. procedures.

rivers.

requests.

application of Re.N.Di.S. procedures.

**Acknowledgements**

**Conflict of interest**

of manuscript submission.

**List of acronyms**

Luca Franzi1 \*, Gennaro Bianco2 , Alessandro Pezzoli<sup>3</sup> and Angelo Besana4

\*Address all correspondence to: luca.franzi@regione.piemonte.it

1 Soil Defence Department, Regione Piemonte, Torino, Italy

2 DIATI - Politecnico di Torino and Turin University, Torino, Italy

3 DIST - Politecnico di Torino and Turin University and R3C – Politecnico di Torino, Torino, Italy

4 DIST - Politecnico di Torino and Turin University, Torino, Italy
