Ghiaia dei Risi

Original name

Landslide movement in Ghiaia dei Risi

Geographic Area

Ghiaia dei Risi, Italy

Reference Project

Documentation of the landslide movement in Ghiaia dei Risi

Site description

The need for documentation arises following a collaboration with the Department of Earth and Environmental Sciences of the University of Pavia. The serious landslides were evident on Sunday 26 January 2020.The landslide affected four houses, three of which inhabited only in the summer period and one occupied by a permanent resident. All four houses and the road to reach them have been declared unsafe by the competent bodies. The first containment interventions were carried out already in 2017 following some subsidence of the land. The Municipality has proceeded in the past years with interventions to slow down the advance of the landslide front. The administration carried out works for a total cost of over 65 thousand euros, with the aim of reducing the water content in the subsoil by controlling the flows from the mountain and removing the water retained by the ground through the draining trenches. Three years ago, thanks to a loan granted by the Region, the Municipality had intervened with a consolidation work along the slope of the hill, for a cost of over 350 thousand euros. The intervention, carried out on a front about 50 meters wide, was not conclusive. The mayor then asked for an intervention from the University of Pavia, activating an intervention of experts and advanced technologies to understand the landslide pattern of the hillside above the hamlet of Ghiaia dei Risi. The Dada LAB laboratory, which is carrying out investigations in collaboration with researchers from the Department of Earth and Environmental Sciences to model the land affected by the landslide, fits into this context.

Credits

Promoted by
Municipality of Borgo Priolo, Italy

Coordinator
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Partnership
UNIPV, University of Pavia
DICAr, Department of Civil Engineering and Architecture
Department of Earth and Environmental Sciences

Survey Activities

Laser Scanner
Elisabetta Doria
Silvia La Placa

UAVs Photogrammetry
Francesca Picchio
Matteo Crozi

Terrestrial Photogrammetry
Elisabetta Doria
Silvia La Placa

Photo
Elisabetta Doria
Silvia La Placa

Post production Activities

3D Models
Elisabetta Doria
Silvia La Placa
Matteo Crozi

  • Gallery
  • 3D Model

Documentation Methodology

The landslide movement’s documentation actions were carried out in 2020, despite the current health emergency, due to the gravity of the local situation and the importance of the intervention. the survey was carried out in two phases.

The TLS laser scanner survey campaign was planned with FARO Focus S150 which produced 41 scans for the description of the external environments of the building's factory and the hillside. All the reference targets were marked with GPS tracking in order to geolocate the models obtained. In parallel, a photogrammetric acquisition of the external facings and roofs was envisaged through UAVs remotely piloted systems, conducted with DJI RTK drone and DJI Mavic drone. The laser scanner survey of a slope was complex and we wanted to proceed with a second experiment.

During the second phase the survey was carried out using Lidar technology with KAARTA stencils, a quick survey of less detail than the TLS but ideal for describing the natural external environment and reading the movements and morphologies of the ground. A second flight was also conducted with DJI RTK drone to have a comparison between the two models. All the reference targets were marked with GPS tracking in order to geolocate the models obtained. The models obtained from the survey conducted by the DAda LAB laboratory were shared with the collaborators of the University of Pavia to proceed with accurate modeling of the landslides found in order to study intervention models on critical situations.

Bibliography

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