Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Synthetic "debris flow initiation hazard map"

Firstly, a standard form devoted to “debris flow risk analysis” was a reference document. It was designed by ARMINES.M.GI/ENSMP.CGI in a previous research project.

The identification of predisposition factors was improved using GIS tools.

The methodology was improved for the mapping of the predisposition factors and resulted in a synthetic “debris flow initiation hazard map”, with an application in the Arbonne catchment (Savoie, France). This map allows the identification of material sources areas and then various potential scenarios of debris flow initiation can be analysed, with the associated volumes.

These scenarios have to be characterized with reference to a typology of debris flow initiation and mobilization processes. This typology, previously established, refers to 12 main processes. The classification proposed is based on geomorphologic surveys performed in many Alpine debris flow source areas and underlines the importance of local conditions related to geology, geomorphology, hydrology and hydrogeology.

As a consequence of these general results, scenarios of debris flow events can be analysed in a qualitative manner, with the objective of determining orders of magnitude of the following volumes, considering field conditions: volumes available in the source areas, volumes which are liable to be mobilized into debris flow materials, volumes which are liable to reach the lower parts of the catchment.

Reported by

UMLV-CGI, Bât IFI, 5 Bd Descartes
77454 Champs-sur-Marne, Marne-la-Vallé