In the context of developing innovative solutions and strategies to address landslide risks, the TWINFALL project proposes the development of digital twins based on advanced numerical approaches and monitoring systems.
The project's case studies are located in the Pre-Alpine region, an area already impacted by hydrogeological risks that are expected to worsen due to climate change. As in this area rockfalls and debris flows are the primary phenomena likely to worsen, the project aims to develop digital twins for these two types of landslides, equipping local authorities with essential tools to manage hydrogeological risks. The digital twins will be a detailed virtual representation of the slopes in the selected pilot cases, integrating mathematical models and simulations with both traditional and innovative monitoring systems. The continuous monitoring will allow for real-time observation of slope changes, supporting the development of early warning systems, and for updates to the model, providing new scenarios based on quantitative data. Additionally, simulations incorporating climate change scenarios will offer valuable decision-making support to local authorities, aiding in the development of mitigation and evacuation plans, and the design of tailored engineering solutions.
Rockfalls will be modelled on two different scales: large rock masses and small blocks, which are nonetheless significant for citizen safety.
The selected case studies are located in the Province of Lecco. For large rock mass collapses, the study will focus on the Torrioni di Rialba (Abbadia Lariana) and Monte San Martino (Lecco). Regarding the widespread small-block rockfalls, the outcrops above the road connecting Ballabio to the Pian dei Resinelli area will be considered. The small channels near the Rotary trail (Lecco) and the Meria catchment (Mandello del Lario) will be the case studies for debris flows.
The monitoring will involve innovative and traditional technologies, as gauge stations for measuring weather and hydraulic variables using Arduino systems, PhotoMonitoring with optical/multispectral sensors to obtain information about ground changes or displacements through appropriate Digital Image Processing techniques, photogrammetric surveys using UAVs and thermal cameras, seismic noise recording to track subtle spectral and polarization changes in rock structures and to quantify sediment transport.
The active involvement of local communities will be promoted to ensure the effectiveness and sustainability of protection measures. This purpose will be pursued through the development of a mobile application for rockfall and debris flow data collection. Encouraging direct citizen participation through involvement in monitoring activities fosters a sense of shared responsibility and strengthens social resilience against hydrogeological risks. Moreover, this approach will improve the collection and analysis of multi-temporal data, providing an accurate picture of rockfall and debris flow phenomena, that is necessary to create highly specific and predictive digital twins.
The use of a mobile application will allow both technicians and citizens to participate in the monitoring process. The app will enable the collection of geolocated images precisely aligned with a previously available reference photo, thanks to the integration of an advanced algorithm for matching singular points.
Advances in numerical modelling will allow for the design of the architecture of the digital twins. A cutting-edge solution for predicting rockfalls and simulating their runout consist in the use of the Material Point Method alongside phase-field modelling for fracture propagation. The advantage provided by these numerical models is integrating real-time monitoring data, making them particularly suitable to digital twin development. Furthermore, regarding innovative debris flow modelling, the improvement of an existing physically based model, SMART-SED, is plann