Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 14, 2469-2485, 2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
17 Sep 2014
Analysis of the French insurance market exposure to floods: a stochastic model combining river overflow and surface runoff
D. Moncoulon1,2, D. Labat2, J. Ardon1, E. Leblois3, T. Onfroy1, C. Poulard3, S. Aji1, A. Rémy4, and A. Quantin1 1CCR, 157 bvd Haussmann, 75008 Paris, France
2GET, 14 av. Edouard Belin, 31400 Toulouse, France
3IRSTEA, Centre de Lyon, 5 rue de la Doua, CS70077, 69626 Villeurbanne CEDEX, France
4Macif, 2 et 4 rue de Pied de Fond, 79037 Niort CEDEX 09, France
Abstract. The analysis of flood exposure at a national scale for the French insurance market must combine the generation of a probabilistic event set of all possible (but which have not yet occurred) flood situations with hazard and damage modeling. In this study, hazard and damage models are calibrated on a 1995–2010 historical event set, both for hazard results (river flow, flooded areas) and loss estimations. Thus, uncertainties in the deterministic estimation of a single event loss are known before simulating a probabilistic event set. To take into account at least 90 % of the insured flood losses, the probabilistic event set must combine the river overflow (small and large catchments) with the surface runoff, due to heavy rainfall, on the slopes of the watershed. Indeed, internal studies of the CCR (Caisse Centrale de Reassurance) claim database have shown that approximately 45 % of the insured flood losses are located inside the floodplains and 45 % outside. Another 10 % is due to sea surge floods and groundwater rise. In this approach, two independent probabilistic methods are combined to create a single flood loss distribution: a generation of fictive river flows based on the historical records of the river gauge network and a generation of fictive rain fields on small catchments, calibrated on the 1958–2010 Météo-France rain database SAFRAN. All the events in the probabilistic event sets are simulated with the deterministic model. This hazard and damage distribution is used to simulate the flood losses at the national scale for an insurance company (Macif) and to generate flood areas associated with hazard return periods. The flood maps concern river overflow and surface water runoff. Validation of these maps is conducted by comparison with the address located claim data on a small catchment (downstream Argens).
Please read the corrigendum first before accessing the article.

Citation: Moncoulon, D., Labat, D., Ardon, J., Leblois, E., Onfroy, T., Poulard, C., Aji, S., Rémy, A., and Quantin, A.: Analysis of the French insurance market exposure to floods: a stochastic model combining river overflow and surface runoff, Nat. Hazards Earth Syst. Sci., 14, 2469-2485,, 2014.
Publications Copernicus