implement functional sediment connectivity analysis.
In this context, a UAV survey represents the main
source of high temporal resolution topographic data
allowing the generation of several 3D products from
LiDAR or Photogrammetric processing. Among these
products, Digital Elevation Models are fundamental to
derive structural connectivity parameters while DEMs
of Difference are used to estimate the impact of
topographic changes. Therefore, a multi-temporal
analysis is crucial to successfully achieve the goal of
the Morpheus project. In the case of this project, the
regions particularly studied in the framework of
sediment connectivity include Liguria, Veneto and
Friuli Venezia Giulia. The selected study areas
encompass several catchments located in contrasting
landscapes of northern Italy and featuring different
sediment transport processes. Among the many, Rio
Cucco basin (0.65 Km
2
) saw an extreme event in 2003
that triggered an unusually large debris flow in the
area.
In order to test the multi-source, multi-scale and
multi-temporal coherence of spatial heterogeneous
data, fundamental for assessing the impact of
topographic changes, a UAV- based survey of Rio
Cucco was conducted by our team in June 2024. The
presence of a natural pine forest over much of the
basin surface directed us toward the choice of a
LiDAR sensor for dense point cloud acquisition and
DEM production. After post-processing and analysis
of these datasets, a comparison was needed with the
same type of data provided by EAGLE FVG (official
geo portal of Friuli Venezia Giulia). The aim from this
comparison is to document the temporal changes
occurring in Rio Cucco and to harmonize different
datasets referred to the same study area. To this
purpose, the data will be analysed and validated in
terms of point clouds density, georeferencing,
accuracy, and uncertainties by exploiting data co-
registration algorithms. Furthermore,
to assure the
optimal output for the geomorphometric approach, a
land cover classification procedure was tested relying
on a simple deep learning model.
2 STUDY AREA
The Rio Cucco basin is a torrential watercourse
located in the municipality of Malborghetto-Valbruna
(Udine, Italy) where it serves as a right tributary of the
Fella River. Its watershed comprises two sub-basins,
fed by smaller channels and two main branches that
converge into an alluvial fan near the village of Cucco.
The basin's geology features dolomites and dolomitic
limestones from the Anisian Ladinian period
(Dolomia dello Sciliar), along with nodular
limestones, marls, and calcarenites in its upper areas.
The southern slopes of Monte Cucco are marked by
vertical rocky cliffs, frequent rockfalls, and debris
accumulations, particularly in regions dominated by
friable calcareous and dolomitic rocks prone to
thermoclastism and cryoclastism.
The alluvial fan, spanning roughly 0.2 km², hosts
a natural pine forest of black pine and Scots pine in its
apex and residential areas, meadows, and a state road
bridge at its lower end. The predominantly south-
facing aspect, combined with arid conditions caused
by the area's permeability and frequent material
deposition, inhibits soil formation. Annual
precipitation averages 1,500 mm, with summer and
autumn peaks corresponding to increased debris flow
activity. Significant flood events, such as those in June
1996 and August 2003, caused extensive sediment
mobilization and damage, with the latter involving
325 mm of rainfall over 12 hours and the transport of
approximately 80,000 m³ of sediment.
After the 2003 flood, more than 300 million euros
were invested throughout the Valcanale and Canal del
Ferro to secure, restore existing hydraulic works as
well as build new structures on the most affected
basins (FVG Region, 2007). Two branches of the
basin were extensively reworked with the construction
of cross works and berms, which converge to a
downstream storage basin of 100,000 m
3
. The latter,
in particular, is protected by two cyclopean boulder
embankments, joined by a filtering weir that conveys
the solid-liquid material to a reinforced concrete gutter
near the State Road crossing, which is followed by
another channelling work in cemented boulders to the
point of discharge into the Fella River. The basin plays
a vital role in mitigating flood risks, directing
sediment-laden flows into reinforced concrete
channels towards the Fella River. Figure 1 shows the
location of the basin with respect to the surrounding
area.
Figure 1: Rio Cucco Basin.