Marco Baldo

ADVICE: A New Approach for Near-Real-Time Monitoring of Surface Displacements in Landslide Hazard Scenarios

We present a new method for near-real-time monitoring of surface displacements due to landslide phenomena, namely ADVanced dIsplaCement monitoring system for Early warning (ADVICE). The procedure includes: (i) data acquisition and transfer protocols; (ii) data collection, filtering, and validation; (iii) data analysis and restitution through a set of dedicated software; (iv) recognition of displacement/velocity threshold, early warning messages via SMS and/or emails; (v) automatic publication of the results on a dedicated webpage. We show how the system evolved and the results obtained by applying ADVICE over three years into a real early warning scenario relevant to a large earthflow located in southern Italy. ADVICE has speed-up and facilitated the understanding of the landslide phenomenon, the communication of the monitoring results to the partners, and consequently the decision-making process in a critical scenario. Our work might have potential applications not only for landslide monitoring but also in other contexts, as monitoring of other geohazards and of complex infrastructures, as open-pit mines, buildings, dams, etc.

Landslide 3D Surface Deformation Model Obtained Via RTS Measurements

We present a new procedure that allows retrieving in near-real-time 3D surface deformation models starting from data acquired via Robotized Total Stations (RTS). The RTS measurements are first pre-processed and then implemented on 3D maps that include vector arrows representative of the intensities and of the real directions of motion in a given system of coordinates. The 3D surface deformation models are finally overlain on a DTM and/or on an updated picture of the monitored area. We discuss an example of application to an active large-scale landslide located in the area of Montaguto (southern Italy, ca. 100 km northeast from Naples). In this complex landslide scenario, the use of 3D representations of the surface deformation simplified the understanding of the evolution of the landslide phenomenon and received positive feedbacks from operators of the Italian Civil Protection Department.

The Use of Micro-UAV to Monitor Active Landslide Scenarios

We present a procedure to use micro-UAV (Unmanned Aerial Vehicles) to perform photogrammetry survey and monitoring analysis in landslide scenarios. The employed methodology is mainly composed of two phases: the first one is the UAV mission planning and execution, while the latter is the picture elaboration and alignment. The UAV used during all tests here described has been developed for photographic applications. Thanks to its “V” shape, propellers do not fall within camera field during normal flight operation and the eight motors configuration ensures more reliability in urban areas uses than a classical quadcopter configuration. The processing of the acquired photos relies on both standard photogrammetry procedure as well as innovative methods for photo alignment derived from computer vision algorithms. Examples of application are also provided to show the results and the potential of this methodology in real landslide scenarios.

Relationship between man-made environment and slope stability: the case of 2014 rainfall events in the terraced landscape of the Liguria region (northwestern Italy)

ABSTRACT In the autumn of 2014, a series of rainfall events affected several sectors of the Liguria region, triggering many shallow landslides and causing three casualties and severe structural damages. The most intensely unstable area covered 385 km2, in which more than 1600 landslides have been identified. After these events, an airborne Light Detection and Ranging survey was carried out. The survey yielded a high-resolution digital terrain model (DTM) and aerial images that provided a means of identifying and mapping all the occurred landslides. The distribution analysis of slope instabilities highlighted the link with various human activities. In fact, the majority of the detected landslides occurred in man-modified areas. Geospatial and statistical analyses provided the identification of three main anthropic factors: terraces, their level of maintenance and road network. Moreover, they quantified their role in landslide triggering. These factors were not analysed as separate elements, but as a continuous process, overlapping in time, in man-made influence on landscape. The identification of such factors is a key element for a correct behaviour characterization of this landscape towards extreme flash floods events.

Traces of the active Capitignano and San Giovanni faults (Abruzzi Apennines, Italy)

ABSTRACT We present a 1:20,000 scale map of the traces of the active Capitignano and San Giovanni faults in the area of the Montereale basin (central Apennines, Italy) covering an area of about 80 km2. Detailed fault mapping is based on high-resolution topography from airborne LiDAR imagery validated by extensive ground truthing and geophysical prospecting. Our analysis allowed the recognition of several features related to fault activity, even in scarcely accessible areas characterized by dense vegetation cover and rugged terrain. The identified fault traces run at the base of the NW-SE striking Montereale basin-bounding mountain front and along the base of the southwestern slope of the Monte Mozzano ridge, and have a length of about 12 and 8 km, respectively. Improving the knowledge of fault geometry is a critical issue not only for the recognition of seismogenic sources but also for surface fault hazard assessment and for local urban planning. The knowledge of the exact location of the fault traces is also crucial for the seismogenic characterization of the active faults by means of paleoseismological trenching.

The Use of Airborne LiDAR Data in Basin-Fan System Monitoring: An Example from Southern Calabria (Italy)

To analyse morphologic and volumetric changes within an active basin-fan system of about 0.250 km2 in Calabria (South Italy), we compare two high-resolution DTMs (50 cm) derived from aerial LiDAR surveys conducted in October 2012 and May 2013. The comparison allowed us to: (i) evaluate the magnitude of erosion-transport-sedimentation processes (ii) identify the extent of an active landslide within the feeder sub-basin, and (iii) confirm the fan, feeder channel and feeder basin dynamics obtained from previous works based on geological and geomorphological field surveys. The results demonstrate that the LiDAR techniques can be a useful tool for the monitoring of geomorphological changes in areas affected by severe erosion and depositional processes.

Infrastructure in Geohazard Contexts: The Importance of Automatic and Near-Real-Time Monitoring

The analysis and interpretation of ground deformation plays an important role in monitoring activities aimed at ensuring the safety of people and/or infrastructure in geohazard scenarios such as earthquakes, volcanic activity and landslides. Nowadays, a wide spectrum of instruments and methods is available, ranging from in-situ to remote sensing approaches. However, the research described here was primarily to develop automatic, and increasingly accurate, monitoring instruments, while acknowledging that the available tools for an efficient exploitation, understanding and interpretation of the measurements made still lack efficiency.

Near Real Time Monitoring Systems and Periodic Surveys Using a Multi Sensors UAV: The Case of Ponzano Landslide

Following the heavy snowfalls in the central and southern Italy at the end of winter 2017, the reactivation of many landslides in the Apennines area was observed. Some of them had already been subject to several seismic events, with main shocks on 08/24/2016 (M6.0) and 10/26/2016 (M5.9). This paper shows preliminary results concerning the Ponzano landslide activity (Civitella del Tronto—Italy), located in the central Italy at about 40 km from the 2016 main earthquakes areas. This landslide reactivated in the last days of February 2017 with displacements of more than 8 meters in the first few days, probably due to the fast snowmelt (about 1.2 m snowpack, accumulated in the middle of January). In accordance with the Department of Civil Protection, different monitoring systems have been foreseen in order to describe the behavior of the landslide and to monitor the oldest part of the village. To reach these goals, a near-real time monitoring approach was implemented by means of a robotized total station. Additionally, a series of UAV aerial surveys for a multi-temporal site analysis were accomplished. The first approach allowed to perform a continuous displacement monitoring (frequency of measurements 0.5 h ÷ 2 h) and to detect landslide movements due to spring rainfalls. The second one allowed us to perform a rapid mapping of the area immediately after the main reactivation, and its evolution after a few months. Thanks to a modular fixed wing multisensor UAV recently developed in our institute, it was possible to perform a survey using optical and multispectral sensors. In this work, we present the results obtained by both systems, and we describe how they can be used in the emergency scenarios and in subsequent landslide management phases.

Rapid mapping application of vegetated terraces based on high resolution airborne LiDAR

Abstract The aim of this work is to define a methodology for terraced areas survey and rapid mapping in a complex environment, like Ligurian (Northwestern Italy) one, where a remarkable percentage of its surface is estimated as terraced and where the canopy coverage makes their recognition very hard. Methodology steps are the definition of LiDAR survey parameters, morphometric filtering and GIS processing for final mapping. Each phase is oriented to provide a reliable terrace mapping, also practicable in canopy-covered areas due to a particular attention to land cover influence. The work considers a case study (Rupinaro basin) close to Cinque Terre, with a mixed land cover (terraces, forest and urbanized areas). The methodology provided encouraging results detecting 448 ha of terraces, 95% of them located under canopy cover. This finding pointed out that terraces mapping cannot rely only on photo-interpretation, as canopies will hamper their detection. Mapping of these areas, frequently characterized by abandonment, is crucial while identifying potential trigger factors for slope instabilities. This case study highlighted the importance of a carefully planned production chain, that should start from LiDAR survey parameter choice, providing the best input for analysis algorithm and providing the correct identification of terraces.

Multitemporal Study of the San Martino Sulla Marrucina Landslide (Central Italy)

In this study, we aim at achieving details on the San Martino Sulla Marrucina (SM) landslide failure mechanisms. The SM landslide represents one of the most complex and large-scale mass movements recently occurred in the Chieti province (Central Italy). We present the preliminary results of an integrated study based on a multidisciplinary approach. The investigated phenomenon represents a local reactivation of a wider quiescent landslide and that its morphological evolution is doubtless characterized by a retrogressive trend. Furthermore, we propose a geodynamic model based on deep kinematic conditioning. The data collected, integrated with those already existent, will permit further investigations of the landslide susceptibility in the municipality territory and in the surrounding areas.