Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 10 5 2010 10.5194/nhess-10-999-2010 http://www.nat-hazards-earth-syst-sci.net/10/999/2010/ http://www.nat-hazards-earth-syst-sci.net/10/999/2010/nhess-10-999-2010.html http://www.nat-hazards-earth-syst-sci.net/10/999/2010/nhess-10-999-2010.pdf 999 1008 2010-05-10 Risk management on an alluvial fan: a case study of the 2008 debris-flow event at Villar Pellice (Piedmont, N-W Italy) M. Arattano R. Conte L. Franzi luca.franzi@regione.piemonte.it D. Giordan A. Lazzari F. Luino Italian National Research Council, Istituto di Ricerca per la Protezione Idrogeologica, Torino, Italy Regione Piemonte, Civil Protection Department, Torino, Italy Regione Piemonte, Public Works, Soil Defence Department, Torino, Italy In the Piedmont Region (North-Western Italy), the regional authorities manage debris flow risk by following the ideal sequence of steps that are generally pursued in land planning and civil protection activities. Complex procedures and methods are elaborated and widely discussed with politicians, economists and the general public. On the contrary, in emergency situations, civil protection agencies generally prefer the adoption of simple and flexible criteria. In this paper, a catastrophic debris flow event, that occurred in 2008 in Villar Pellice, is described in this perspective, after an analysis of the triggering rainfalls and of the effects on human life and properties. 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