The fifth webinar of the LandAware 2026 webinar series “From Monitoring to Decision: Lessons Learned from the Mont de La Saxe Landslide Early Warning System”, by Davide Bertolo (K4T -Knowledge for Tomorrow, Italy) is scheduled for 28 May 2026, 14:00 UTC.
Abstract:
Landslide Early Warning Systems (LEWS) are increasingly based on high-frequency monitoring data and the definition of empirical thresholds. However, operational experience has shown that the exceedance of such thresholds does not always lead to failure, posing significant challenges for decision-makers responsible for issuing warnings.
This presentation discusses the lessons learned from the management of the Mont de La Saxe landslide (Aosta Valley, Italy), one of the most intensively monitored large slope instabilities in the Alps. Between 2012 and 2014, the site experienced critical acceleration phases that required the activation of civil protection measures under conditions of high uncertainty.
The experience highlighted key limitations of threshold-based approaches, particularly in terms of false alarms and decision reliability. In response, a multi-stage decision framework was progressively developed, integrating data from different monitoring systems with field observations and contextual information.
The presentation will focus on the practical challenges faced during the emergency, the evolution of the early warning procedure, and the operational strategies adopted to support timely and reliable decisions. Particular attention will be given to how combining multiple lines of evidence can improve confidence in warning levels and reduce the risk of both false alarms and missed events.
The Mont de La Saxe case provides a concrete example of how early warning systems can evolve from purely data-driven approaches to more structured and transparent decision processes, offering insights that are transferable to other monitored slope instabilities and relevant for international LEWS initiatives such as LandAware.

Bio:
Davide Bertolo is an engineering geologist with more than 25 years of experience in landslide risk management, monitoring systems, and civil protection decision-making. He has served as Head of the Geological Survey of the Autonomous Region of Aosta Valley (Italy), where he led the development and implementation of advanced monitoring networks for large alpine instabilities, including the Mont de La Saxe landslide.
His work focuses on bridging the gap between data acquisition and decision-making, with particular emphasis on early warning systems and probabilistic approaches to risk management. He is the author of a Bayesian-based early warning methodology that integrates quantitative monitoring data with qualitative field evidence to support transparent and robust decision processes.
Davide is currently founder of K4T, an advisory initiative focused on innovative solutions for geological risk and civil protection, combining domain expertise with advanced data analysis and decision-support methodologies.



