Abstract
Abstract In mountain drainage basins, channel morphology and fluvial dynamics are heavily controlled by landslide sediment supply and local transport capacity. Although the importance of hillslope-channel coupling has long been acknowledged, the downstream effect of landslide activity on fluvial sediment transport is largely unknown. This is a critical gap for evaluating hillslope-channel feedback mechanisms and contemporary sediment budgets, as well as for addressing issues of sediment management in compliance with EU Water Frame (2000/60/EC) and Floods (2007/60/EC) Directives. This project aims to: (1) provide a methodological framework for estimating landslide-related sediment transfer across a range of representative settings in the Northern Apennines, with a focus on sediment supply to the fluvial drainage network; (2) evaluate geomorphic changes along mountain streams of the Northern Apennines, at the decadal and the event scale, particularly in relation to the extreme floods experienced by Romagna rivers in 2023 and 2024; (3) produce guided workflows for assessing sediment dynamics and potential response at the basin scale. Methods include (1) combinations of field, proximal, and remote sensing techniques for compiling landslide inventories, through which evaluate rates of sediment supply to the drainage network (WP1); (2) field, proximal and remotely-based monitoring of landslide-related geomorphic change and sediment transfer on hillslopes and along channels (WP2); (3) spatially-distributed modelling of sediment transport and connectivity for assessing fluvial response scenarios to varying rates of landslide sediment supply, hence propose sediment management strategies (WP3). WP4 will undertake dissemination towards the scientific community and relevant stakeholders. LASST will exploit opportunities offered by emerging technologies, such as UAV and airborne LiDAR-derived high-resolution topography. It will adopt state-of-art tools for computing geomorphic change detection to quantify fluvial sediment budgets. The range of expertise in the LASST working group ensures that the project will be at the forefront of the current technological transition, but yet grounded on empirical data. LASST devotes specific efforts to generalize models and tools developed for the proposed case studies. Overall, LASST will complement national initiatives that characterize the hydro-morphological conditions of Italian fluvial systems (IDRAIM and IRIS), by focusing on intermontane fluvial systems of the Northern Apennines. In these settings, where inherited effects of past anthropogenic disturbance have led to dramatic channel bed incision and reduced sediment export to the sea, LASST will address how landslide sediment supply and enhancement of fluvial continuity can mitigate the existing sedimentary disequilibrium.
Results achieved
The University of Bologna research unit focused on the analysis of fluvial geomorphic responses to sediment inputs and extreme rainfall events. Research activities included the investigation of channel adjustments and sediment redistribution processes in confined mountain streams. Multi-temporal analyses of aerial imagery and digital elevation models were used to evaluate channel evolution and sediment dynamics. In this case, the investigation was extended (beyond the Marecchia and Sillaro Rivers) to two highly confined stream channels of the Marnoso-Arenacea formation, the Senio and Savio Rivers, which experienced multiple severe storms across the 2023-2024 period. These studies demonstrated that extreme rainfall events can produce substantial geomorphic changes and significantly modify sediment transport conditions in river systems. The UNIBO unit also contributed to the interpretation of sediment connectivity patterns and to the integration of hillslope and channel processes within basin-scale sediment budgets. The main scientific outputs include (i) peer-reviewed publications addressing landslide activity and sediment dynamics in the Northern Apennines. Conference contributions presenting advances in modelling landslide-driven sediment supply and fluvial responses; (ii) invited presentations and lectures aimed at disseminating project methodologies and results; (iii) technical reports and methodological documentation describing datasets and modelling workflows. The project generated several open datasets and digital products supporting reproducibility and data sharing, including: (i) multi-temporal landslide inventories; (ii) UAV multispectral datasets; (iii) drainage network datasets derived from high-resolution digital terrain models; (iv) modelling outputs from sediment transport simulations. These outputs contribute to improving the quantitative understanding of sediment transfer processes in landslide-dominated mountain drainage basins.Project details
Unibo Team Leader: Francesco Brardinoni
Unibo involved Department/s:
Dipartimento di Scienze Biologiche, Geologiche e Ambientali
Coordinator:
CNR - Consiglio Nazionale delle Ricerche(Italy)
Total Unibo Contribution: Euro (EUR) 63.920,00
Project Duration in months: 24
Start Date:
28/09/2023
End Date:
28/02/2026
