A 240-year history of avalanche risk in the Vosges Mountains based on non-conventional (re)sources

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGEInternational audienceDespite the strong societal impact of mountain risks, their systematic documentation remains poor. Therefore, snow avalanche chronologies exceeding several decades are exceptional, especially in medium-high mountain ranges. This article implements a combination of historical and geographical methods leading to the reconstruction, at the scale of the entire Vosges Mountains (north-east of France), of more than 700 avalanches that have occurred since the late eighteenth century on 128 paths. The clearly episodic nature of the derived geo-chronology can be explained by three interrelated factors that have changed together over time: the body and reliability of sources, social practices conditioning the vulnerability and the natural hazard itself. Finally, the geo-chronology reflects the changes in the meaning of the hazard in social space. Specifically, the event which could be retrieved from the historical sources is an aspect of the interaction between society and its environment. These results confirm the role of the historian in contextualising and evaluating such data. It transforms these data into information that is relevant for mitigating risk and understanding its change over time. The work also demonstrates the usefulness of constructing an original database from a diverse suite of historical data and field investigations. This approach could be applied to other risk phenomena in the frequent situation in which archival data are sparse