The landslide dam of Ventia Creek (Umbria, central Italy)

A landslide dam is a natural phenomenon where a large amount of materials coming from slopes cause a damming of a river. This paper presents a case of dammed river where the natural lake is still now stable. Type and volume of materials are the main aspects that control such phenomena. Using geostatistics approaches, coupling auxiliary map to the elevations data, a higher quality digital elevation model is obtained. The comparison between the DEM before-event and after-event has allowed a better estimation of volume involved and the identification of main landslide features like the crown, the zone of depletion and the accumulation zone. The study has allowed to develop a method where, in case of lack of topographic data, through geostatistical interpolation techniques and using auxiliary maps, is possible to achieve a better definition of the digital terrain model, and therefore a more accurate assessment of mobilized volumes during the event.