Abstract
Abstract. The geomorphological change detection through the comparison of repeated topographic surveys is a recent approach that benefits greatly from the latest developments in topographical data acquisition techniques. Among them, airborne LiDAR makes the monitoring of geomorphological changes a more reliable and accurate approach for natural hazard and risk management. In this study, two LiDAR digital terrain models (DTMs) (2 m resolution) were acquired just before and after a complex 340 000 m3 landslide event (4 November 2010) that generated a debris flow in the channel of the Rotolon catchment (eastern Italian Alps). The analysis of these data was used to set up the initial condition for the application of a dynamic model. The comparison between the pre- and post-event DTMs allowed us to identify erosion and depositional areas and the volume of the landslide. The knowledge of the phenomenon dynamics was the base of a sound back analysis of the event with the 3-D numerical model DAN3D. This particular code was selected for its capability to modify the rheology and the parameters of the moving mass during run-out, as actually observed along the path of the 2010 debris flow. Nowadays some portions of Mt. Rotolon flank are still moving and show signs of detachment. The same soil parameters used in the back-analysis model could be used to simulate the run-out for possible future landslides, allowing us to generate reliable risk scenarios useful for awareness of civil defense and strategy of emergency plans.
Highlights
Recent improvements in topographical data acquisition techniques and software allow us to derive high-resolution digital terrain models (DTMs) and develop new methodologies for analyzing earth surface processes (e.g. McKean and Roering, 2004; Lane et al, 2004; Lashermes et al, 2007; Iwahashi et al, 2012; Cavalli et al, 2013; Tarolli, 2014)
Comparisons of light detection and ranging (LiDAR)-derived DTMs obtained from successive surveys make it possible to produce DEM of differences (DoD) maps, which are a valuable tool to interpret the evolution of geomorphological processes and to quantitatively assess morphological changes due to erosion and deposition on rivers (Lane et al, 2003; Wheaton et al, 2010; Picco et al, 2013;) and in case of debris flows (Scheidl et al, 2008; Theule et al, 2012; Blasone et al, 2014) and landslides (Burns et al, 2010; DeLong et al, 2012)
In 2013, Worni et al stated that the future challenges in numerical modelling of flows are linked to the capability of understanding precisely the dynamic of the phenomena and to the availability of high-resolution DTMs
Summary
Recent improvements in topographical data acquisition techniques and software allow us to derive high-resolution digital terrain models (DTMs) and develop new methodologies for analyzing earth surface processes (e.g. McKean and Roering, 2004; Lane et al, 2004; Lashermes et al, 2007; Iwahashi et al, 2012; Cavalli et al, 2013; Tarolli, 2014). Comparisons of LiDAR-derived DTMs obtained from successive surveys make it possible to produce DEM of differences (DoD) maps, which are a valuable tool to interpret the evolution of geomorphological processes and to quantitatively assess morphological changes due to erosion and deposition on rivers (Lane et al, 2003; Wheaton et al, 2010; Picco et al, 2013;) and in case of debris flows (Scheidl et al, 2008; Theule et al, 2012; Blasone et al, 2014) and landslides (Burns et al, 2010; DeLong et al, 2012) Another tool broadly used to investigate the dynamics of geomorphological processes is numerical modelling (Hungr et al, 2005, Rickenmann, 2005). In this paper we report the use of DoD maps as a base to calibrate a 3-D model, using the numerical code DAN3D (McDougall and Hungr, 2004), of a large debris flow event that occurred on 4 November 2010 in the eastern Italian Alps
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
